A review of correspondence from NOC-L & Roadholder
A miscellaneous collection of useful ideas
Preventing coil breakdown
If your coils are breaking down at a certain frequency of engine vibration, make sure they aren't earthed, take them out of their clamps, and tape the bodies to stop them earthing. Apparently the coil windings vibrate, and at the correct frequency they short out to the body, especially where the body is badly damaged due to over tightening the clamps). If you find the flat spot goes when the coils are de-earthed, you'll need to replace them.
Dave Taylor (lsd.taylor2@virgin.net) on NOC-L 28th. Feb 1997
Getting a good finish on alloy castings
I learned a while back that the way Enzo Ferrari finished the alloy castings in his cars was to spray them with silver paint, then wipe off as much of the paint as possible immediately with a cloth. I have tried this on BMW castings, and found that a better method is to spray the paint onto the cloth, then wipe it on the alloy. It looks great, and more importantly, it fills the pores of the metal which makes cleaning a simple job. If you don't like the look, wipe off the paint with mineral spirits and try again.
Stan Smith (sks3rd@aol.com) on NOC-L 10th. Mar 1997
Slotting Dominator engine plates for easier removal
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"I am sure I am not the only one to notice that if it wasn't for that bolt which fastens the bottom of the Dominator engine to the engine plate, I would be able to lift out the engine without the gearbox and all it entails. Is there any reason why I should not cut these holes in the plates into slots?" |
Now that you mention it, that explains why the engine plates of my Atlas basket case had been 'modified' in that area. Unfortunately it appears that in this case, the slotting didn't leave enough metal or strength. By the time I got the bike there was almost nothing left under the bolt head and the unsupported part of the plate had broken away. I replaced the plates with another pair. Now I'm wondering if this was a common modification.
Dave Culgan (culgandm@sterlingdi.com) on NOC-L 13th. Mar 1997
Slotting Dominator engine plates - not advised
This is a very common modification, but in my view should be avoided like a case of warts. The Norton twin's engine plates have little enough bearing at the bottom/rear of the cases as it is, and slotting the lower holes will seriously weaken the plates. I've taken the opposite tack when making engine plates: I increase the bearing surface by making the boss area in the engine plate as large as I can, and make the hole a close fit to the stud. It may render the power unit a little more inconvenient to remove, but makes the plates and crankcases much less prone to damage.
Greg Kricorissian (grkricor@ccs.carleton.ca) on NOC-L 14th. Mar 1997
Noise from tachometer drive
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"The tachometer head on my 1960 Model 99 sometimes screeches enough to annoy. where the drive enters. After I spray a little bit of WD 40 carefully around the bearing it all goes quiet for a while but then the screech returns after 100 plus miles." |
In my experience, the screeching you speak of comes from inside the instrument head; most often it's due to the internal bush having run dry, and a complete strip down is in order. Other times, its due to the thrust pad for the shaft on the rotating magnet having worn axially, causing it to rub against the internals. This is most often caused by an unwitting owner fitting a speedo cable with an inner core that protrudes too far into the head ... it causes axial loading of the internal drive when the collar nut is tightened on the outer cable. If you want to experiment with some grease, use the smallest dab you can, because it will almost certainly find itself into the head and gum things up. Better still, try some graphite.
Greg Kricorissian (grkricor@ccs.carleton.ca) on NOC-L 25th. Mar 1997
Modified pillion footrest for use with rearsets
About 8 years ago while at the INOA Rally in Canada I saw a crude passenger footpeg bracket that I have improved upon. It moves the passenger footpegs back to allow the operation of rearsets with a passenger. For those of us who prefer the comfort of rearsets over the stock setup, yet still carry a passenger, this is the answer. I have received a few inquires about the brackets, from people viewing them on my homepage, so I've made a few sets. You can view them direct at http://stripe.colorado.edu/~lines/foot.html or wade through my motorcycle pictures page to find them.
Cliff Lines (lines@stripe.colorado.edu) on NOC-L 2nd. Apr 1997
Determining crankshaft shims required before final assembly
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"I plan to pre-assemble the crankcases with the crankshaft and the new Superblends to measure the crankshaft end play to see if shims are needed. It seems to me that once the inner bearing shells are pressed onto the crankshaft they will be quite a pain to get off, if shims prove to be needed." |
If you have an old inner race from a Superblend bearing, you can grind out the inside diameter a little until it is a loose fit on the shaft. Fit one of the new main bearings to the crank (say, the drive side) then use the old loose fitting inner race on the timing side to establish what shims are required to get the correct end float. Finally fit the new timing side inner race with the appropriate shims behind it.
Andy Holmes (pha59@cc.keele.ac.uk) on NOC-L 10th. Apr 1997
Unique oil tank breather
As for breathers, it's not a good idea to use them as chain-lubers, as do some people, I've seen, do (my own bike came with this bodge on it). Blow-by gases are mostly just water of combustion, emulsified oil and sulphur acids anyway, none of which are good for chains.
I route my breather into an (empty) can of Guinness Extra Stout, housed where the starter motor would sit on a Mk.lll. The colour scheme matches the black-and-gold livery of my Interstate quite nicely.
D.J.Walker(djw12@leicester.ac.uk)on NOC-L 10th. Apr 1997
Gaskets for compression plates
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"I intend to use a steel compression plate to reduce the Combat compression to 'normal'. Should I also use the standard paper gasket in addition to the compression plate and if so, below, above, or one on each side? Alternatively, should I use some kind of liquid gasket?" |
Yes, by all means put a paper gasket on both sides of the compression plate. I recommend using Permatex gasket sealer. I have never had oil leaks with this product and cannot say the same for others I've tried.
Neil Rasband (rasband@beethoven.byu.edu) on NOC-L 21st. Apr 1997
Gearbox reverse camplates
If you need a reverse camplate for the Norton gearbox, eliminating the shift linkage, give me a call.
Heinz Kegler (ytnh94a@prodigy.com) on NOC-L 8th. May 1997
Piston ring gaps
Place the rings, one at a time in the bore, ensuring they are dead square, and check them only at the unworn portion at the top. Use progressively larger feeler gauges to measure the gap: be careful: it is a snug fit in there. Having determined the gap is OK, you can then check again a ½" down to gauge the bore wear ... to ensure the gap is not too large.
I do not believe in re-ringing in bores that are worn near the limit (because of ring expansion/contraction as it travels the bore): it's better to rebore and have it over with. When I rebuilt my Mk.lll, the gaps with the new rings (Hepolites) measured way too small, but the bores were spot on dimension. However, directions with the rings stated explicitly not to file the gaps ... the gaps should be right at the correct bore size. The 'old' rings were also Hepolites (I installed 3 years ago), but their ring gaps were still fine. (I also do not believe in re-installing old rings).
After checking around to get to the bottom of the discrepancies, I found that interpretation of the nominal bore size varies greatly depending on which reference you seek. Some of the Haynes manuals weren't even close in doing the metric conversion. In the end, I decided it was a case of production tolerances adding up in the wrong direction, and that there was no correct answer. What I think is overwhelmingly obvious is that it's better to be too loose, than too tight (within sensible limits!). Thus, I took my pistons, rings and cylinders to a machine shop, and I had the cylinders honed ever so slightly oversize (about a half thou!). This brought the ring gap to the lower tolerance dimension, and the piston skirt clearance a half thou. too generous.
Gregg Kricorissian (grkricor@ccs.carleton.ca) on NOC-L 9th. May 1997
Castrol R
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"I'd like to get that 'R' aroma floating about. The way I see it there are a few options:-" |
- 1) Run Castrol R in the crankcase, and let the residue burn
- 2) Mix some R in the gas (2-4 oz.) and chance fouling a plug
- 3) Mix in castor based 2 stroke oil into the gas (Maxima 927 - 2 to 4 oz.)
- 4) Dump some straight castor into the gas
Alternative to Castrol R
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"I tried option 4, using ~3 oz. per 4 gallons of gas. There was a very slight aroma, but it was definitely a bit tougher to start, although when running, its was fine. Castor oil from the pharmacy is expensive too...$4 for 6 oz!!, whereas the Maxima is $6 for 16 oz. What's the consensus on the best mix?" |
I use Maxima 927 but I probably use a little less than 2 - 4 oz. I bet I use about a shot glass - 1 oz.? maybe 2 oz. at the most. Use something to stir up the tank if you add the oil last; I use a big screwdriver or a tyre spoon. I assume that unless it is well mixed the oil may slither its way into your carburettor in one big glug - probably un-atomisable by any known British carb. This may be your starting problem. I've done this for years with no known problems.
Joe Michaud (triumph@fia.net) on NOC-L 14th. May 1997
Oil soaking of gaskets
Speaking of goop to use on gaskets, a Canadian guy at the 1995 Norton National told me he never used anything, on the various crankcase and gearbox gaskets. Instead, he would just soak them overnight in oil before using them. Supposedly this made them swell up to conform to the irregularities better. I was a little dubious about soaking a gasket in very the fluid you're trying to prevent from leaking through that gasket, but his bike was sparkling, and he said it never leaked oil.
Mike Taglieri (miketync@)juno.com) on NOC-L 24th. May 1997
Wheel alignment
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"Does anyone have an easy guide to aligning the rear wheel? All of that straight edge business seems too hard. Is it OK to run the axle all the way against the slot front or back and back off from there? Or how about using a square and measuring space between the rim and the swinging arm tubing?" |
I did this recently and found the side stand better than the centre. The centre stand gets in the way, and with the bike leaning to one side it's easier to get at the sides of the wheels and tyres.
Place the bike on the side stand, then get a piece of 6 x 1 or something else long, flat and reasonably light. Place the straight edge against both wheels, and with both sides of the front wheel against the edge, look at the contact points on the rear wheel. Adjust the rear wheel with regard to the chain tension so that all four contact points, front wheel and rear wheel are the same. I did this when I was sorting out a bit of a high speed wobble and it helped considerably.
Peter Aslan (miketync@)aol.com on NOC-L 2nd. Jun 1997
Techniques for easier removal of cylinder heads
This problem of installing Norton heads arises because Nortons have their pushrod tunnels permanently cast into the cylinder barrels rather than using the vast array of little tin tubes, rubber washers, etc., found leaking onto older engine designs (the names of which modesty prevents me from mentioning).
The Norton design was a major improvement in oil-tightness, but it makes getting the head off and on with the engine in the frame very tricky indeed if you do it the way the book says; because you're supposed to lift all four pushrods as high as possible into the head and hold them there while you lift the head out of the frame, or you won't have enough clearance to get it out. Six hands are the practical minimum for this job, and most Brit-bikers have only two.
The answer is to use a pair of nylon tie wraps (the kind used on electrical harnesses, etc.) As soon as the head is lifted free from the gasket, put one tie wrap around each pair of pushrods, fastening it so the long end of the tie wrap points out away from the barrel. Snug them up tight enough so that it's a bit difficult to move them up and down on the pushrods. Now, as you remove the head, push the tie wrap down all the way on each pair of pushrods, then put a finger from each hand under the tie wrap on the pushrods to hold it up (and its pair of pushrods) as you're lifting the head free of the engine. Holding each pair of pushrods this way leaves you eight fingers to lift the head out of the frame. it will be easy to keep the pushrods snug against the head and you'll clear the frame with no danger of bending a pushrod, and no extra hands needed. After the head is off, keep the tie wraps on the pushrods (unless you need to service them, of course), so you can tell the left pair from the right pair by the direction that the end of the tie wrap is pointing.
To reinstall the head, just hold the pushrods high up in the head with a finger on the tie wrap as you did before while lifting the head loosely onto the barrel. Once the head is past the frame and over the barrel, with the pushrods in their tunnels, you don't need the tie wraps anymore, so snip each one off while holding the long end, to be sure no nylon bit falls into the engine. Note that the only purpose of this trick is to keep the pushrods out of harm's way during removal and installation of the head. During installation, you still have to follow the book and be sure the pushrods are properly located on their rocker-arms before tightening down the head bolts, or a pushrod could be bent.
If, like the writer, you've already taken the head off by the traditional blood and chaos method, you can still put it back on with the tie-wrap method; firstly making sure the pushrods damaged during removal have been replaced and all skin lacerations have stopped oozing, which could cause rust. You simply have to put a tie wrap on each pair of pushrods, aiming the end of the tie wrap toward the outside of each pair so you'll be able to tell the left from right. If you've mixed them up already, you'll survive, but it's better practice not to interchange pairs.
I invented this trick many years ago, and used it last October on my ring-job with no problem, even though I was out of practice. Easier head installation is probably the only good thing that can be said about separate pushrod tubes of the earlier engine designs - this trick makes Norton head removal and installation almost as easy, without giving up the oil-tightness and durability of cast-in pushrod tunnels.
Mike Taglieri (miketync@)juno.com on NOC-L 3rd. Jun 1997
Spray cleaner - a product recommendation
I ran across a product at my local friendly Honda dealer that works really well. At the suggestion of the guy at the parts counter, I picked up a can of 'Spray Cleaner & Polish' by Pro Honda. It is an aerosol cleaner & wax similar to 'Lemon Pledge' but thicker, and of course, it wipes streak free on a variety of surfaces.
A couple of weeks ago, I used it to clean up the wooden artillery wheels on my old 1929 Hudson. The results were little short of spectacular, cleaning and shining paint, natural finished wood, rubber, chrome and aluminum, and in far less time than I am used to spending. It is made in the U.S.A. exclusively for Honda.
Paul O'Neil (hudson29@aol.com) on NOC-L 14th. Jul 1997
Fitting studs into alloy
In my experience, studs often pull out of alloy blocks because they have not been securely bottomed out in their threads. Bottoming the stud so that it contacts the alloy at bottom of the stud hole preloads the thread, and minimizes fretting from vibration during use. By all means, when you discover a loose stud, re-thread its hole in the alloy block with a coarse thread, and make up a double-diameter stud to replace it.
Alternatives include fitting a 'TimeCert', which is like a solid HeliCoil. In any case, when rebuilding any engine, check all the stud holes to ensure the threads are perfectly clean, and in good condition so they retain the stud securely. Any kind of dirt in the holes will lead to early failure due to abrading the alloy threads.
Gregg Kricorissian (grkricor@ccs.carleton.ca) on NOC-L 22nd. Jul 1997
Refilling gearbox oil
When refilling the gearbox with oil, you can easily see the inside of the level plug from the open inspection hole by pointing a flashlight down and to the rear. By looking at it, and gauging the oil level visually, you don't need to remove the level plug, saving the mess of oil all over the exhaust pipe and frame when the surplus runs out.
Paul O'Neil (hudson29@aol.com) on NOC-L 20th. Aug 1997
Something else that may be obvious, but is sometimes overlooked, is that when you re-fill a dry gearbox, you should kick over the engine a few times, to distribute the oil inside the box, and then let it sit for a while before making a final level measurement. You'll be surprised how much it settles.
Greg Kricorissian (grkricor@ccs.carleton.ca) on NOC-L 21st. Aug 1997
Vibration from loose crankcase securing bolt
On my 1973 850, I had recently noticed a strange 'feeling' in my twist grip under large throttle openings / high r.p.m. The sensation is sort of hard to describe, kind of like a weird vibration or something. The cause turned out to be that the middle bolt that attaches the crankcase to the cradle had come loose. After tightening it the sensation completely went away. I just thought that I'd pass this observation along in case someone else notices a similar strange sensation in their twist grip.
Eric Goforth (ericgoforth@compuserve.com) on NOC-L 22nd. Aug 1997
Checking wheel alignment to eliminate steering wobble
Try this tip for wobble, I had the problem and it worked to greatly minimize it.
Tip your bike against a wall so that it is resting on its handle bar and not the kick stand or center stand. Get a long (and straight) 2" x 4". Press it firmly against the front and back tyres. Do they line up? Both wheels should line up so that the both front tyre and back tyre have 2 points of contact with the 2" x 4", that is on the rims of the rubber. If not adjust the rear tyre so that it does. Even 1/16" out of alignment makes a big difference in handling.
Steven R. Schoner (dm550@cleveland.freenet.edu) on NOC-L 14th. Sep 1997
Removing seized disc brake pistons
Drill and tap the caliper at the flat, inaccessible side (nearest the spokes). Fit a shortened bolt from a car seat belt anchorage, they all seem to be 7/16" UNF, but what makes them attractive is the thin hex head (it clears the spokes). Choose a bolt that is threaded all the way and not shouldered, and a thin washer (I've used fibre ones). The hole of course is so you can insert a drift and tap out any stubborn piston. I've done this on 3 Commandos with no problems.
Jordan Princic (jordan@zip.com.au) on NOC-L 30th. Jan 1998
Stripped exhaust port 'get you home' fixes
A temporary fix is the beer can. Take a pair of scissors and cut a piece of aluminium the size of the threads on the nut. It's kind of a trick to get it in there, but if you put it in the hole in a sort of conical fashion it will catch and give enough hold to hold the pipe against the gasket.
Eric Williams Lamberts (ewl@med.unr.edu) on NOC-L 3rd. Feb 1998
I have in the past done a 'road side fix' by using several large hose clamps going above and below the exhaust pipe around the head and then using some wire to keep the 'band aids' from slipping apart. It held the exhaust pipe in place until I could get home and do a proper fix. The last time I did this, it lasted for the duration of my trip to Canada, over 3000 miles; so it does work, it just looks a bit strange.
John Ebert (jmebert@worldnet.att.net) on NOC-L 3rd. Feb 1998
A cure for leaking Commando fuel tank caps
When our local club secretary had his Commando catch fire and burn out after a backfire through the carburettor recently, it concentrated my mind on my leaking gas cap. Even with a new seal and careful attention to the tank rim it still poured out on the slightest lean when the tank was full. I decided it must be leaking up the shaft the seal holder slides on, but there was no access, as the end of the hollow shaft is peened over.
I ground the peened part off and disassembled it. Sure enough there is another seal on the shaft which prevents petrol taking this route out, and mine was perished. There is no part number for it but a piece of any petrol-proof rubber pipe of a similar size cut very neatly to length will do. When reassembling, a small washer and a self tapper took the place of the peened part of the pipe to hold it all together. A lot cheaper than a new cap!
Chris Ghent (we@amaze.net.au) on NOC-L 27th. Feb 1998
Fixing a loose bearing
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"My drive side bearing inner is loose on the crankshaft; I renewed the bearing and used bearing Loctite to prevent the inner from turning, but after a few hundred miles it started to move again. Any suggestions?" |
Have the i.d. of the inner race copper plated, about .002" thick. It worked great for me, though on the o.d. of the drive side and timing side bearings in my case. Talk to your plating company about how to insulate the area you don't want plated; I did mine with big washers.
Heinz Kegler (ytnh94a@prodigy.com) on NOC-L 11th. Apr 1998
Clutch tightening
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"I'm not ready to put the rear tyre together yet but would like to finish the primary; how do I tighten the clutch hub retaining bolt to seventy ft. lbs. without the rear chain and tyre on?" |
I made a tool to do this from two old clutch plates, one outer and one inner. Bolt or weld them together concentrically (in line !!) and weld or bolt about 2 feet of 1" x 1/8" or similar flat bar to the pair, bent in a 'Z' to clear the primary case. Slip the tool into the clutch, engaging the inner and outer drive slots and hold the handle as you do everything up. It works for clutch centres, and with the primary chain fitted, the engine sprocket nut as well.
Angelo (rubberboy@dial.pipex.com) on NOC-L 13th. Apr 1998
Use a piece of mild steel bar about 1 - 1¼" wide and 3/16" thick, which is bent at the ends to form a slight 'S'. The length of the bar is such that it is too long to fit between the two chainwheels in the primary so that by engaging the ends into the space between the teeth on both sprockets you can jam the primary solid without loading the primary chain. It works both ways (doing up/undoing) and also for the clutch/alternator. It is small enough to carry with you if you're into roadside repairs!
Martin Edridge (martin.edridge@rcn.org.uk) on NOC-L 14th. Apr 1998
Fitting pistons without a ring compressor
I never even use a ring compressor. I found an easier way, putting the pistons in the cylinders before attaching them to the rods. That's easier because you can install them with the cylinder upside-down on your workbench and carefully ease the rings in place one-by-one. If you put the inside circlips on before you do this, you can slide the pins in from the outside as you lower the cylinders onto the rods. This was so much easier that I'll never go back to the old way, at least for 360-degree twins.
Mike Taglieri (miketync@)juno.com on NOC-L 3rd. Mar 1998
Removing rust from the inside of petrol tanks
A cement mixer is good for removing rust, etc from inside tanks. Just put some nuts and bolts inside, stuff in with blankets to protect outside, and switch on for a while.
Jordan Princic (jordan@zip.com.au) on NOC-L 10th. Jun 1998
Eliminating the Boyer solder joint failure
I too have experienced the problem with the pickup board 's connectors. Solution-- get rid of them! (the bullet connectors that is).
What is happening is that the wires going through the board and point soldered are weakening, then breaking at the point where they enter the board. This creates a minute break in the circuit that can be very frustrating to eliminate. The bike will run perfectly one moment, then die the next.
What I did to fix mine, was to unsolder the wires, removing them from the board. Next I carefully drilled out the two holes so that short 6-32 brass screws could fit through (make sure the heads do not touch). Next, screw a brass nut to the other end, then solder the head to the board. Then replace the bullet end of the wires that go to the Boyer black box with regular 'Y' blade connectors, using a brass nut to secure them to the altered circuit board pickup module.
Steven R. Schoner (dm550@cleveland.freenet.edu) on NOC-L 7th. Jul 1998
I would caution that a direct soldered set-up such as that described has failed on my bike - the wires actually fracturing within the insulation. In my experience, unless you have somehow shorted out a Boyer, all defects of the system can be found close to the backplate connectors. Curiously, the very early Boyer had screw connectors, long since discarded. They never failed by breaking, but occasionally came undone. This gave me a great familiarity with the 'inexplicable' popping and banging and trying-to-run-backwards symptoms of an ailing Boyer, which has set me in good store a couple of times since.
A useful trick to help diagnose faulty wiring between backplate and Boyer unit: take your plugs out, switch on and move the wires around as much as you can. When you hear the plugs clicking, you've found the dodgy connection or broken wire.
Joe Schofield (skywings@bhpa.co.uk) on NOC-L 8th. Jul 1998
Spokes
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"Reassembling the wheels of my 1961 Dominator, I have noticed there are two different types of spokes, not in length but in the length of the 'hooks'" |
The outer spokes have a longer 'hook' as well as a sharper bend because they have to bend around the flange.
Vernon Fueston (fueston@snowcrest.net) on NOC-L 28th. Jul 1998
Commando blows oil over the rear end at higher r.p.m.
This sounds like the crankshaft oil seal. Crankcase pressure blows engine oil into the primary chaincase which then becomes overfilled and leaks out of the final drive. A good test is to take out the primary level plug and see if oil comes out; if it does then it was over full. If it is not clean then it has probably got engine oil mixed up in it.
Treve Whitford (magdis@nortonownersclub.org) on NOC-L 30th. Jul 1998
Replacing the Commando drive side crankshaft oil seal without rebuilding the engine
You do have to pull the drive sprocket and clutch but the primary inner does not have to come off. When you pull the sprocket you can see the seal immediately behind it. The woodruff key needs to come out too. The hardest part is to get hold of the seal to pull it out. To do this I drilled a hole in the metal part of it (about 1/8th." I think), being very careful not to damage the alloy crankcase. Centre punch first. Then with a stiff piece of wire, bend the tip to a right angle and insert in the hole as a hook (yes I used a coat hanger). Pull the seal out.
Chris Ghent (we@amaze.net.au) on NOC-L 19th. Aug 1998
Alternatively, drill two small holes opposite one another in the metal part of the seal and screw in two self tapping screws until they contact the crankcase. Then screw them in evenly, thus forcing the seal out.
Treve Whitford (magdis@nortonownersclub.org) on NOC-L 19th. Aug 1998
When inserting the new seal, it has to go in very evenly, but it helps if the sharp edge on the outside of the seal is removed with a sanding disk or file before the seal is fitted. A piece of pipe the with an i.d. slightly larger than the shaft and an OD slightly smaller than the o.d. of the seal is the de-luxe tool for doing this job. Used with a mallet it makes the fitment of seals a breeze. Oh, and remember to oil the shaft before fitting the seal.
Colin Sharpe (sharpe_colin@videojet.com) on NOC-L 19th. Aug 1998
Commando rear brake safety modification
This month's Classic Bike had an article on how to make your Commando more reliable. One of the things they pointed out was that in the event of the rear brake cable breaking, the rear brake pedal can swing downward and dig into the pavement with disastrous results. They showed an aftermarket spring, but didn't say where to get it.
I went out and looked at mine and added a piece of piano wire as a back up safety. I looped it once around the bolt that is mid position on the brake pedal, then up and around the footpeg support, then back down and around the wire. The loop is stiff and large enough to move up and down with the brake pedal, but will hold the pedal up in event of rear brake cable failure.
Eric Lamberts (ewl@med.unr.edu) on NOC-L 1st. Oct 1998
Fitting oil seals without damaging the lip
When fitting an oil seal and there's some danger that a sharp edge might damage the sealing lip, use kitchen aluminium foil to wrap around the sharp bits. This helps protect the seal, and can be easily applied and removed after.
Jordan Princic (jordan@zip.com.au) on NOC-L 2nd. Oct 1998
Removing the Commando kickstart bush
I put in a new bush in my kickstart shaft and it appears that I pushed it in too far because the kickstart shaft had significant end play, about 40thou. I dropped a 3/8" nut in the shaft, then I dropped a 3/8" i.d. washer that was fairly thick and filed in an elliptical shape. Then I used a 3/8" drive socket as a spacer against the kickstart inner face and threaded a 3/8" rod into the nut. Along with a second nut and washer on the socket I was able to pull the bush out as far as I needed. It would be easy to pull the whole thing out as well.
With about 18" of threaded rod and a bunch of washers and an assortment of 3/8" drive sockets you can install and remove swing arm bushes, hub bearings, and steering head bearings without hammering them once. If you have a lathe you can make the right spacers, but what's the challenge in that?
Bob Patton (bpatton@humboldt1.com) on NOC-L 12th. Oct 1998
Fill the oil grooves in the section that goes into the bush of the kickstart shaft with 5-minute epoxy or the like. Put the kickstart shaft into a soft-jawed vice with the bush facing up, and fill the bush with the heaviest oil you can find or a light grease that flows easily without leaving any air pockets in the hole. Put the layshaft into the first 1/8" or so of the bush and give the end of the layshaft a couple of judicious whacks with a hammer. As the bush doesn't extend into the full depth of the hole, the hydraulic pressure will drive the bush out. Oh yes, and don't forget to wrap a rag tightly around the top of the kickstart shaft after inserting the layshaft or you'll have grease all over your ceiling (believe me, I know)!
John Hayduska (lists@benaco.com) on NOC-L 12th. Oct 1998
Generating logos and transfers (decals)
Computer scanning and laser cutting can be useful in several ways:-
Firstly for the generation of self adhesive decals (stickers); it's even possible to use a hand held scanner on an existing (compound curve) tank decal and get a good result.
Secondly, if you don't want decals (because they move, slide, fade, aren't the right colour, get taken off by fuel etc.) it's possible to cut masking film (Friskit) with the laser and you can use the computer to make either positives or negatives or mirrors and inverts. You can use these to mask either the background or the foreground, spray the logo you want, have colours peeking through and then lacquer over the whole thing to give it immense depth and a contiguous surface that is totally impervious to all of those challenging issues mentioned above.
For those in the UK, there is a good production company in Chester, GB Signs Ltd. Charges are reasonable as well.
Colin Steer (goscard@aol.com) on NOC-L 21st. Oct 1998
Repairing leaky tanks
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"After rebuilding my Commando, I recognized that the petrol tank was leaking. A closer inspection has shown that the leak is about apart from the left-hand front stud screw under the tank. I would like to repair the tank without touching its high quality surface finish. Is there any way, such as the use of a resin/plastic product, of repairing the leakage without welding or soldering and damaging the paintwork?" |
I've had good success with repair of a leak on a Dunstall tank I use for racing. I took the tank to a reputable autobody (panel beater) shop where the fellows first briskly rinsed the tank with acetone. They used moderate air pressure in the tank to assure the acetone washed through the partings and broken seams of the fibreglass tank. They then dried it out with air.
I recommend the pressuring up of the tank, especially with acetone, be left to those knowledgeable and with the correct equipment. The fellow at the shop then mixed a slow setting resin and again used moderate compressed air to force the resin through all the partings and broken seams. Afterwards, he periodically rotated the tank to let the resin accumulate in 'strategic' spots in the tank (along the problem seam) to assure an accumulation of resin. I realize that the ultimate fix is to route out all the bad areas and re-glass them, but this above outlined approach has been an effective remedy for me.
John Magyar (paslan@uk.mdis.com) on NOC-L 17th. Sep 1998
I would drain the tank and wash it out, then put it on its back with the bad side up. Close the gas tap and blow air at LOW pressure into one of the gas taps, leaving the other one closed. Brush on soapy water and mark all leaks. Clean scrupulously around the leaks and if the tank is thick enough make an inverted vee cut around the leak. (You want the bottom of your cut to be wider than the top of the cut).
Repair with Maine epoxy or other epoxy that is gasoline (petrol) proof. A good store that specializes in plastics and fibreglass can help. In the US there is an epoxy available at any hardware store called JB Weld that works just fine. Take your time. Handle the tank like fine china--it is probably more fragile. When you turn the paint side down, use a towel or blanket to protect the paint. Don't drop it, and be very careful of the front of the tank as you remove it from the bike, unless you've chipped it already, (like mine!), in which case you don't have to worry.
You might want to seal the tank; either marine epoxy, or one of the tank sealing kits available at motorcycle dealers will do the trick. The plus side of sealing is that if you have one leak, you may well have another, that will make your new paint job bubble up. The downside is that most of the chemicals used in sealing tanks can be paint destroyers, and you must exercise extraordinary caution to keep them off the paint, although I had little problem when I sealed mine. Preparation for sealing is key; if your tank is not scrupulously clean when you seal, you will have wasted your time and made a bad situation worse.
Eric Lamberts (ewr@med.unr.edu) on NOC-L 11th. Nov 1998
You are not patching a hole you are trying to stop a steel insert from pulling out of the tank. If you look at the front studs on the tank you will see a circle around the base. That is where the insert is friction welded in the tank and the leak will be around that circle.
The only solution, in my opinion, is TIG welding. TIG is localised and the heat should not affect the paint job too much. Clean the tank out with detergent and water first and weld with water in the tank , it will help to disperse the heat. A good TIG welder should be able to repair this with a minimum of damage to the rest of the tank; I know because it is what I do every day. Try the epoxy first if you like but I think this is the best solution. This problem is usually caused by vibration and/or using the bike without the rear tank mounting.
Chris Tilley (t.tilley@virgin.net) on NOC-L 11th. Nov 1998
It would seem to me that the answer depends at least partly on whether the leak is caused by a crack or by minor rust. If it is caused by a crack, then during subsequent use the crack will 'travel' and lengthen. This may cause the leak to start again, even if sealing had been successful. In the worst case, the crack may travel around the welded insert for the stud, causing it to break out ... this is a very frequent failure on Commando oil tanks.
Since the area you're describing is under the tank and not visible when the tank is installed, why not just bite the bullet and have the leak MIG welded? Done carefully and in small stages, MIG welding will not cause much heat build up. Having thus repaired the crack, it should be easy to touch up the repair afterwards since the damage will be localised.
Greg Kricorissian (greg-k@spyder-it.com) on NOC-L 11th. Nov 1998
In the UK a product called Petseal, a 2-part resin thing, has been around for years and is very effective at sealing tanks. However, in my experience a leak so close to the mounting studs on the Interstate tank is indicative of major fatigue damage. I have seen tanks with a 4-5 cm2 area torn out of the bottom of the tank by the stud. If you use resin, be very sure beforehand that there is no further damage lying in wait. If you do have more damage, I think welding is the only fix.
Joe Schofield (skywings@bhpa.co.uk) on NOC-L 11th. Nov 1998
I have to agree with this response. I had the exact same problem with a newly painted Interstate tank, which was finally fixed by welding the stud into the hole. It was done with minimal blistering in the area within an inch or two of the stud and not obvious once the tank was on the bike.
Mike Sullivan (sullivan@inwave .com) on NOC-L 11th. Nov 1998
The tank must be properly supported. There should be a whole load of foam sheets which fix to the underside of the tank above the top frame spine tube (the big one). This supports the tank and if it is missing, all the weight is carried on the front mountings and the rear tank underside. Unfortunately this is a common problem on restorations.
Peter Aslan (paslan@uk.mdis.com) on NOC-L 12th. Nov 1998
Commando sidestand problems
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"My Commando side stand always goes up under the silencer when raised, no matter how I bend the last few inches. Also, a new spring makes it seem worse." |
Do you have the rubber buffer (06-3324) installed on the metal bump near the middle of the stand on its top? This buffer contacts the frame tube to keep the stand from riding too far in underneath when the stand is retracted. These rubbers are known to get chewed up and fall off, so buy a few at a time and use some cement to mount it on the stand's knob.
David Schmidt (dschmidt@voicemnet.com) on NOC-L 26th. Nov 1998
You need a tighter bush for the side stand or a bigger bolt.
Vic Churchill (mountanort@ozemail.com.au) on NOC-L 26th. Nov 1998
I had the same problem and cured it by bending it so that when the stand is fully forward (i.e. with the bike resting on it), the 'spike' points straight up. Then, I put a 4" length of neoprene fuel hose onto the spike, so that it would protrude past the muffler when the stand is stowed.
Greg Kricorissian (gregg-k@spyder-it.com) on NOC-L 26th. Nov 1998
When this happens to mine it always seems to mean I need a new bolt in the pivot. They get bent very easily. The bolt should be tight in the hole, and the flanges on the stand and on the frame, which come together and act as a stop to prevent the stand from going out any further, should have square shoulders. The tang is then in the right place and easily snared with a heel when bent as original.
At the other end of the stand I have always had trouble with the small rubber bung which is supposed to contact the frame and stop the stand from going underneath (mine's a 1973 750; I think some others may have a different setup). The small mushroom peg on the stand which the bung fits over cuts through the bung when it hits the frame as if made for the job and I went through a number of bungs quickly. The mushroom had also started to cut its way through the frame.
I filed the sharp edges off the mushroom but this made no difference to the bung use rate. In the end I cut off a piece of pushbike inner tube about three inches long and strapped this around the frame with a couple of plastic wiring ties. When the stand comes around the bung hits the rubber rather than the metal and the soft landing means the bung does not get cut up. I can flick the stand around and let the spring pull it in with a bang and the bung still survives. This is out of sight and no-one has ever noticed the inner tube. It's a crude but successful mod.
Chris Ghent (we@amaze.net.au) on NOC-L 26th. Nov 1998
It sounds like either your stand is bent or more likely the bush is worn at the pivot. If there is any play in the pivot, fix that and all your problems should disappear; well, not all but the problem with your sidestand at least. I had similar problems with mine and had a bush made to be snug in the stand and shimmed vertically so that there was no play at all. The little bump stop I bought from Norvil is quite hard and plasticy and pressed on nicely over the noddy on the stand and never comes off. The stand functions perfectly, is not modified and gives no grief.
Martin Edridge (martin.edridge@rcn.org.uk) on NOC-L 26th. Nov 1998
Try placing a Jubilee clip on the frame, where the rubber bumper on the side stand strikes the lower frame tube. Set the clip so the screw hits the rubber buffer. I've been using this modification for the past 10 years or so and it works fine. If I were to ever strip to the frame for a total restoration, I would consider welding a bracket to the frame at this point to perform the same purpose.
Peter Aslan (paslan@uk.mdis.com) on NOC-L 26th. Nov 1998
This problem can occur when the sidestand bushing and bolt is worn, and possibly even the hole in the stand where the bushing goes in. I suggest you dismantle and inspect, replacing any worn parts. The bolt, nut and spring are available from dealers. If your problem doesn't go away, you'll have to build up the part of the plate attached to the frame with weld to replace material lost over the years. It's this missing metal that makes the stand use the silencer or frame as a stop. But you should also have a rubber knob on the little bobble cast into the stand, which should bear on the frame.
Joe Schofield (skywings@bhpa.co.uk) on NOC-L 26th. Nov 1998
Steering damper modifications
I'd thought about the trick head steady for my Mk.lll, but really improved the high speed handling in another way: I fitted an adjustable hydraulic steering damper. Around town I would leave it at '0', and on the highway, just dial in a damping figure of about '6'.
I used a generic tubular damper from a bike shop, as made for a BMW as I recall. Its body is about 1" in diameter, and has a sliding rod passing through it, about 18" long. There is a dial that allows you to adjust the damping from 'off' to 'full', and on most you can do it while mobile ... actually, to be more useful you should be sure that you can adjust it while on the move.
Most bike 'go-faster' shops sell various types of these dampers, ranging from about $69 to $295. This one was a $129 variety. (The more expensive ones are a little more glitzy, and made from fluted alloy from compressed rocking horse droppings)
The damper came with an alloy lug to fit into the bore of the steering stem, which attaches to the sliding rod that passes through the body.
The damper body had a threaded stud on a sort of hinge, to fasten to the frame. This allows the damper to self align as the forks are moved.
I machined up a split clamp from alloy billet, to grab the left side downtube just below the tank. I threaded the body of the clamp for the damper's stud.
I had to modify the alloy lug that came with the damper to fit the bore of the Commando's steering stem by reducing its diameter. This lug was exactly like the goose neck that holds the handlebars on a common bicycle. The alternative to the alloy lug at the fork end is to make a split clamp that grabs the stanchion, but then you have to remove your headlamp bracket, or your gaiters. It may an alternative if you're running the original 'wiper' boots.
The main trick is to ensure that the damper rod is exactly at half its travel when the front wheel is pointing straight ahead i.e. ensure it does not run out of travel when you move the forks from full left to right.
Greg Kricorissian (dgregg-k@spyder-it.com) on NOC-L 6th. Mar 1999
Eliminate the oil line across the cylinder head (twins)
I was contemplating drilling the intake rocker spindles, which allows you to eliminate the oil line across the top of the head, because the oil can feed from one side to the other through the spindles.
I think this modification was invented by Brian Slark years ago, but I've never heard anything about it. Has anyone tried this procedure, and is there any downside? Since some of the oilway drillings in the head look like 1/16" or smaller, I assume just about any size hole larger than that will allow sufficient oil to pass.
Mike Taglieri (miket_ync@juno.com) on NOC-L 14th. Jun 1999
I've known people who have done this, but always wondered why it has not become more popular. Perhaps it's because of the potential for starving the feed to the drive side rockers if the timing side clearances become a bit slack.
So far as drilling the rocker shafts, they are made from hardened steel, which could make drilling quite a problem. I suspect they are case hardened, so once you grind through the skin (likely 0.010" deep), you could drill the remainder with a good cobalt bit. As far as the diameter of the hole, go for 1/8" to ensure you don't create a restriction, and further you won't risk plugging with odd bits of 'stuff'.
Gregg Kricorissian (gregg-k@spyder-it.com) on NOC-L 14th. Jun 1999
Do-it-yourself magnetic sump plug
For machines which were not fitted with a magnetic sump plug, you can fit the magnet off of a refrigerator magnet and put it into the middle of the brass gauze. That should catch any metal filings. I have done this on my 850 Commando as a back-up for the magnetic drain plug and I always get a few extra bits of metal that may not have been caught otherwise.
John Ebert (jmebert@worldnet.att.net) on NOC-L 22nd. Jun 1999
A check for piston slap
Here's a possible test that might tell you something. Warm up the engine, then stop it, remove the plug on that side, and pour in some very heavy oil -- STP oil-treatment is almost honey-like, so perhaps a blend of that with regular oil would be about right. Then run the engine again. If the noise is something involving too loose a fit of the piston, the thick oil should gum that up and make the noise stop for a few seconds, then it will come back as the thick oil is dissipated. If the thick oil has no effect on the noise, it is probably not piston-related.
Mike Taglieri (miket_ync@juno.com) on NOC-L 28th. Jan 2000
