Skip to main content
000000 000003 000006 000009 000012 000015 000018 000021 000024 000027 000030 000033 000036 000039 000042 000045 000048 000051 000054 000057 000060 000063 000066 000069 000072 000075 000078 000081 000084 000087 000090 000093 000096 000099 000102 000105 000108 000111 000114 000117 000120 000123 000126 000129 000132 000135 000138 000141 000144 000147 000150 000153 000156 000159 000162 000165 000168 000171 000174 000177 000180 000183 000186 000189 000192 000195 000198 000201 000204 000207 000210 000213 000216 000219 000222 000225 000228 000231 000234 000237 000240 000243 000246 000249 000252 000255 000258 000261 000264 000267 000270 000273 000276 000279 000282 000285 000288 000291 000294 000297 000300 000303 000306 000309 000312 000318 000321 000324 000327 000330 000333 000336 000339 000342 000345 000348 000351 000354 000357 000360 000363 000366 000369 000372 000375 000378 000381 000384 000387 000390 000393 000396 000399 000402 000405 000408 000411 000414 000417 000420 000423 000426 000429 000432 000435 000438 000441 000444 000447 000450 000453 000456 000459 000462 000465 000468 000471 000474 000477 000480 000483 000486 000489 000492 000495 000498 000501 000504 000507 000510 000513 000516 000519 000522 000525 000528 000531 000534 000537 000540 000543 000546 000549 000552 000555 000558 000561 000564 000567 000570 000573 000576 000579 000582 000585 000588 000591 000594 000597 000600 000603 000606 000609 000612 000615 000618 000621 000624 000627 000630 000633 000636 000639 000642 000645 000648 000651 000654 000657 000660 000663 000666 000669 000672 000675 000678 000681 000684 000687 000690 000693 000696 000699 000702 000705 000708 000711 000714 000717 000720 000723 000726 000729 000732 000735 000738 000741 000744 000747 000750 000753 000756 000759 000762 000765 000768 000771 000774 000777 000780 000783 000786 000789 000792 000795 000798 000801 000804 000807 000810 000813 000816 000819 000822 000825 000828 000831 000834 000837 000840 000843 000846 000849 000852 000855 000858 000861 000864 000867 000870 000873 000876 000879 000882
English French German Italian Spanish

Non starter and the novice

Forums

I'm a novice MkIII commando owner. After some early trouble I thought I was beginning to get the knack of getting this beautiful bike going (it had been sittng for a while so got someone to help clean out carbs and some other suggestions people made). A couple of weeks ago I went on a fairly long run out of London and all seemed ok. Bike left for a week. I then tried to start it again and struggled but eventually managed to do so. However, it kept cutting out and wasn't very easy to kick start again. It also wasn't pulling properly either and I brought it straight back home.

Over the last week, I've charged the battery, checked there's more than 12v but I just cant get it to start. It has a Boyer ignition.

Any advice gratefully received. I'd love to get it up to Norfolk in a couple of weeks.

Michael

Permalink

Previously michael_macneil wrote:

I'm a novice MkIII commando owner. After some early trouble I thought I was beginning to get the knack of getting this beautiful bike going (it had been sittng for a while so got someone to help clean out carbs and some other suggestions people made). A couple of weeks ago I went on a fairly long run out of London and all seemed ok. Bike left for a week. I then tried to start it again and struggled but eventually managed to do so. However, it kept cutting out and wasn't very easy to kick start again. It also wasn't pulling properly either and I brought it straight back home.

Over the last week, I've charged the battery, checked there's more than 12v but I just cant get it to start. It has a Boyer ignition.

Any advice gratefully received. I'd love to get it up to Norfolk in a couple of weeks.

Michael

If you have at least 12V in the battery then the Boyer is excellent. Not needed to touch mine since fitted in 1989.

Petrol these days is a bit dodgy, contaminated with ethanol and this can upset running and damage parts in the fuel system. Try some BP Ultimate.

If not fuel quality and supply (Have you check the filters in the top of the petrol taps?) then the fault could be electrical. I still use the original coils but they have been known to break down. Same goes for HT leads. Are both plugs the same colour, is one wet with petrol? tracing the problem to one cylinder simplifies things as does knowing it is both affected.

A single AmalMk 1 932 was the way I went. Not only did it simplify things, give a smoother throttle action but also upped fuel consumption to 68 mpg average. A new R/H carb from Amal comes with ethanol resistant parts. (You will need to take out the black air filter and replace it with the earlier or after market item and buy the earlier bracket for the side panel, all straight forward)

Please keep us updated.

Permalink

probaly wet sumped take the drain plug out the sump and see if any oil comes out if it does let it.

now check you have enough oil in the tank and try starting it again.

my mk111 has the same problem if left for two weeks the factory anty drain valve sticks open.

my es2 will start no problem wet sumped

Permalink

Neil,

Let's get some terms sorted out once and for all for your postings.

Contamination refers to the presence of something that is not meant to be there. A lot of modern petrol is formulated to contain ethanol. Whether you agree with it or not, the ethanol is a component of the formulation. It is not a contaminant.

Whatever your views on current petrol formulations, please use appropriate terminology to avoid confusion.

Permalink

Previously robert_wright wrote:

probaly wet sumped take the drain plug out the sump and see if any oil comes out if it does let it.

now check you have enough oil in the tank and try starting it again.

my mk111 has the same problem if left for two weeks the factory anty drain valve sticks open.

my es2 will start no problem wet sumped

I am fed-up with owners going on about wet sumping its will not stop a Norton from starting and fitting taps anti-wet sumping valves only masks the real problem of a wearing oil pump, I try looking at the wiring and Ignition system first if this is working right then go to the fuel side, to find the fault its a processes

of elimination

yours anna j

Permalink

Previously Chris Grimmett wrote:

Neil,

Let's get some terms sorted out once and for all for your postings.

Contamination refers to the presence of something that is not meant to be there. A lot of modern petrol is formulated to contain ethanol. Whether you agree with it or not, the ethanol is a component of the formulation. It is not a contaminant.

Whatever your views on current petrol formulations, please use appropriate terminology to avoid confusion.

Crikey Chris, that was pretty pompous! Do you think we are all daft enough not to understand what Neil is refering to, when he refers to fuel being 'contaminated' by ethanol?

As a matter of fact, you are incorrect in saying that 'contamination refers to the presence of something that is not meant to be there'. It refers to something which makes a substance less pure, and I agree with that 100%!!

Ethanol is rubbish, foisted on us forreasons political, not practical, and it is common knowledge it causes problems, not least of which classic vehicles catching fire, etc etc. It won't go away, that is for sure, but rather than bury our heads in the sand, we need to be aware of it's pitfalls.

Ian

Permalink

Anna's correct Michael,you need to work through methodically & eliminate one by one.You need electrickery, fuel and air to run, make a list and work through it & don't forget the simple stuff!.

If you can't start:

First thing: Check you haven't knocked the kill switch to 'off'' (I did this coming off the ferry in Santander a few years ago, kicked myself purple in the heat - I bet I am not the first person to do this)

Do you have a nice spark off the plug? If not check your wiring, plug gap, fresh plugsc,fuse, boyer wires in the points cover (known weak point), coils etc

If you have a spark,..

Do you have fuel in n the carbs?,check the tank - should you be on main or reserve?Try with both main & reserve taps on (blocked tap?), drain off some fuel (is it contaminated with water)? etc

Is the tank breather clogged (may start but like dreams will then fade & die)? Any splits in the air hoses to carb or balance tube etc

My MK III needs more than a week to wet sump, you could as a precaution try draining the sump. I normally do this if a check in the oil tank reveals mainlyair. I would not recommend strating with a wet sumped engine.

Re starting, you don't say what carbs you have, I went back to2 (new) Amals some time ago;tickle to flood (I've removedchoke slides, the design is perverse), get pistons to just on compression, then give it the long swinging kick with plenty of weight behind it.

Good luck, let us know how you get on

Regards Mike

MK III Commando

Permalink

Chris G, I agree 100% with what Ian C has written above.

Yes, this business is political and centres around government renewable targets. (Not the well being of historic vehicles)

In the USA, the first Bill put through by the Obama administration was to call CO2 a pollutant. This despite CO2 being absolutely necessary as the essential ingredient in the photosynthesisprocess, allowing us and our Norton's to breath by turning CO2 into oxygen. (Mixed with mostly Nitrogen = air) Perhaps just for you Chris, one should therefore suggest that instead of saying our petrol is contaminated with Ethanol but instead it has been polluted with Ethanol.

And yet the total amount of atmospheric CO2 on Earth is <0.05%, not the whopping 5% Ethanol mix in petrol, introduced by stealth and the 10% as soon as our government can get it on the market to make up their renewable targets set for 2020. Way off at the moment!

If you want to know why Obama classified CO2 as a pollutant, just ask. (In an effort to stick to the fact that there is an unnecessary and harmful agent in our petrol imposed upon us)

The FBHVC(NOC not affiliated) are supposed to be stakeholders in all matters concerning historic vehicles. Why were we not warned about Ethanol in advance, instead of wondering why the Pet seal had turned to gung and fuel hoses leaking, and that just for starters.

Nice to know that some of us are not all in it together and not all brainwashed. (Greenwashed)

But is there a happy ending?

And me, I'm just a Flat Earther, a denier and headless chicken. But more than that, I won't stand for BS and l love and want to protect my Norton's. What's your problem Chris?

Permalink

Same old, same old.

Id bet a thousand to one it's nothing whatever to do with ethanol.

And Anna, so starting a wet sumped bike is no problem eh?

The originator of this thread will go crazy if he takes any notice of you two

Permalink

Hi Michael, assuming you have sparks at the plugsI would check tappet clearance before anything else, tappets could have tightened during previous run which makes for hard starting

Then check ignition timing and carb jets,etc

If the engine was wet sumping it would have done it before your initial good run

Regards Laurence

Permalink

Previously peter_stowe wrote:

Same old, same old.

Id bet a thousand to one it's nothing whatever to do with ethanol.

And Anna, so starting a wet sumped bike is no problem eh?

The originator of this thread will go crazy if he takes any notice of you two

I know what you mean Peter,if it has wet sumped then it will be difficult to get a nice strong swift kick to start it. I certainly don't know any women strong enough to kick start a wet sumped Commando!

Permalink

John, I don't know what Peter means, he's a very rude man but be fair.

When we say wet sumped, do we mean the full contents of the oil tank being in the sump, in which case no chance of starting or are we talking about just a fraction of this? Either way ,this is wet sumping

Permalink

Peter rude? According to you Neil, anyone who does not agree with your fanatical anti ethanol obsession is a complete idiot. How rude is that? Many of us have used a 10% ethanol fuel without any problems.

Permalink

Gentlemen, donât you think we should concentrate on trying to find a solution to Michaelâs problem rather than degenerate this thread into a slanging match?

There have been a few useful suggestions so far, particularly checking the Boyer pick up wiring, as this is notorious for the wire strands breaking inside the insulation where the wires feed through the plate & are cable tied & araldited into place. Outwardly everything looks fine, but as the engine warms up, the insulation expands & the broken strands part, causing a misfire & eventual break down. Check for continuity with a meter & wiggle the wires while checking. If thereâs a problem youâll get erratic readings or no continuity at all. Aside from this, check the basics, as has already been suggested. Make sure you have good regular sparks on both plugs & that the ignition timing hasnât slipped, have you checked that you have the 12v at the boyer black box? Ignition switches can corrode inside & not give full continuity, as can connections in the loom. With the fuel system, if you can flood the carbs, assuming you have concentrics, it should at least start, even if it wonât keep running. If you canât get a good flow of fuel when flooding the carbs, then look for a blockage or restriction. If after going through all the basics you still have no joy, report back with what you have done & what you have found & we may be able to advise further.

Hope you get things sorted & make it to Norfolk, but Iâm sure weâll be able to help you out & get you back on the road if you have problems. Make sure you have the breakdown assistance number with yousmiley

Regards, Tim

Permalink

If its got Amals fitted, it's highly likely that it is dirt in the pilot jet/ airways, especially if it's been standing a while.

If I have sparks at the plugs, not wet sumped, the pilots are the next thing to check- make sure you do it properly- then balance the carbs properly as by the book.

Trying to source ethonal free petrol in the hope that will help is about as much use as praying to a God

Permalink

And your God, Peter, being Algore..!

Sorry Tim but I'm not letting Peter get away with that.

Being a Mk3 owner, I'm interested in what the problem turns out to be and more importantly; what the cure is.

If I may suggest one final piece of advice, that would be to make one change at a time before testing.

A few years ago a mate made 18 changes before finding out he had some duff mag pickups. Though a change of pickups got him going again there were a lot of changes toremember before it was as good as it could be.

Permalink

Previously neil_wyatt wrote:

And your God, Peter, being Algore..!

Sorry Tim but I'm not letting Peter get away with that.

Being a Mk3 owner, I'm interested in what the problem turns out to be and more importantly; what the cure is.

If I may suggest one final piece of advice, that would be to make one change at a time before testing.

A few years ago a mate made 18 changes before finding out he had some duff mag pickups. Though a change of pickups got him going again there were a lot of changes toremember before it was as good as it could be.

No Neil, I have no God, or spiritual leader, or drums to bang on about.

Just my common sense and own observations.

Whereas you appear to be quiet a blinded zealot

Permalink

Hi Michael

I am also a Norton Commando novice, having recently purchased a 1975 Mk2a Intersate, and like you, I am having exactly the same problems. My bike has a Boyer Bransden electronic ignition and a single mikuni carb and if left for more than one day it is absolute murder to start !. Howevrer, once I've exhausted myself and eventuially manage to kick it over, it can stop and start a, kicking it over all day.....bu the next day.....back to difficult starting. I'm also used to kicking over British bikes ( I also have an AJS 500 single)......but like you, I am a total novice with Commando's. The bike is in my local bike garage at the minute andthe initial feelings are thatit may be tappet clearance.....it'll be interesting to see what the final diagnosis eventually is !..........please keep in touch and let me know what your findings are ?.....and hope you get it sorted out

Best wishes

John

PS: Thanks to everyone for the previous useful suggestions re Michael's problems....

Permalink

Your drum to bang, Peter is pro Ethanol. (Miss guidedGreen nonsense)

Now, I suggest we stick to the thread having said our piece, before someone ends the thread and we never find out what the problem is with this Commando. I certainly want to know what the problem(s) are / were.

John above: Might be an idea to see if you have a bad case of wet sumping. See what you get out of the sump the next day after starting. We did have a case on here where the oil tank was emptying over night!

Leaving the engine on compression helps slow down the wet sumping process. With you not using Amal(s)the issues might be different, but again I'm certain we'd be interested to know where the problem is. Keep in touch.

Permalink

Previously John McNicoll wrote:

Previously peter_stowe wrote:

Same old, same old.

Id bet a thousand to one it's nothing whatever to do with ethanol.

And Anna, so starting a wet sumped bike is no problem eh?

The originator of this thread will go crazy if he takes any notice of you two

I know what you mean Peter,if it has wet sumped then it will be difficult to get a nice strong swift kick to start it. I certainly don't know any women strong enough to kick start a wet sumped Commando!

well you just got too know of one now, that can, just take the plugs out and turn the engine over on the kick start for 6 or 7 time and it then near empty the oil out of the sump without doing any damage and you can see if you got some nice big fat sparks at the same times and some fuel will be making its way through as we, then you can fit the plug and have the engine running in on time, I am six foot tall and over 18 stone and can deck any man alive, as I done 25 years in marshal arts witch I took up when I was living in Japan, back in the 70s so do not mess with Anna J

Permalink

Previously peter_stowe wrote:

Same old, same old.

Id bet a thousand to one it's nothing whatever to do with ethanol.

And Anna, so starting a wet sumped bike is no problem eh?

The originator of this thread will go crazy if he takes any notice of you two

Why that peter have you have a degree in engineering then !!

Well if not then I just happen to have a Degree in marine engineering , and use to playing with alot bigger stuff than these toys

, yours anna j

Permalink

Previously neil_wyatt wrote:

Chris G, I agree 100% with what Ian C has written above.

Yes, this business is political and centers around government renewable targets. (Not the well being of historic vehicles)

In the USA, the first Bill put through by the Obama administration was to call CO2 a pollutant. This despite CO2 being absolutely necessary as the essential ingredient in the photosynthesisprocess, allowing us and our Norton's to breath by turning CO2 into oxygen. (Mixed with mostly Nitrogen = air) Perhaps just for you Chris, one should therefore suggest that instead of saying our petrol is contaminated with Ethanol but instead it has been polluted with Ethanol.

And yet the total amount of atmospheric CO2 on Earth is <0.05%, not the whopping 5% Ethanol mix in petrol, introduced by stealth and the 10% as soon as our government can get it on the market to make up their renewable targets set for 2020. Way off at the moment!

If you want to know why Obama classified CO2 as a pollutant, just ask. (In an effort to stick to the fact that there is an unnecessary and harmful agent in our petrol imposed upon us)

The FBHVC(NOC not affiliated) are supposed to be stakeholders in all matters concerning historic vehicles. Why were we not warned about Ethanol in advance, instead of wondering why the Pet seal had turned to gung and fuel hoses leaking, and that just for starters.

Nice to know that some of us are not all in it together and not all brainwashed. (Green-washed)

But is there a happy ending?

null

And me, I'm just a Flat Earthier, a denier and headless chicken. But more than that, I won't stand for BS and l love and want to protect my Norton's. What's your problem Chris?

Well then I got news for you the N.O.C is under the umbrella of the F.B.H.V.C As this is the main body of all historical vehicle clubs thats all clubs and diesel and jet fuel and aluminum oxides & barium oxides are toxic to plants and all life forms , So ask your self why the Government are allowing this Geo-engineering program to go on, you only have too look up and see the chem trails that hang in the sky for hours . contrails only last a few minuits , So whats really going On , there lots going on but the Governments are Not telling us all, were having to find out for our selfs, do your Research yours Anna J

Attachments chemtrail_poster360usa-jpg
Permalink

Hi Michael, I bet you've got fed up reading all this vitriolic infighting haven't you. Do yourself a favour mate and pop along to your nearest NOC branch meeting and ask if someone there will help you sortyour problemout. Most branches will have at least a few very experienced members who would be willing to helpsomeone understand their beast a little better. I amsecretary of the Shenstone branch andif you live anywhere round here we will gladly help you.Look in "Roadholder" for your nearest branch and get in touch with the secretary. "Were here to help"

Cheers Big Alan Clarke Shenstone South Staffs

Permalink

Hope Michael lives in East Yorkshire, Big Alan.!!!!!!!!

Anna, Rosie Pugh, secretary of the FBHvC told me that of all the clubs I was a member of that only the VMCC were affiliated.

Should I give her another grilling?

Permalink

I think all the irrelevance has frightened Michael and his Mk III away. We do need to stick to the topic and be kind and helpful to new members asking advice or we won't attract new members and the club will slowly wither and die.

Permalink

There was quite a discussion a week or two ago about attracting new and younger members. Take a look back through this conversation now and ask yourself; if this was your first insight into the NOC, would you come back?

Permalink

Previously neil_wyatt wrote:

Your drum to bang, Peter is pro Ethanol. (Miss guidedGreen nonsense)

Now, I suggest we stick to the thread having said our piece, before someone ends the thread and we never find out what the problem is with this Commando. I certainly want to know what the problem(s) are / were.

John above: Might be an idea to see if you have a bad case of wet sumping. See what you get out of the sump the next day after starting. We did have a case on here where the oil tank was emptying over night!

Leaving the engine on compression helps slow down the wet sumping process. With you not using Amal(s)the issues might be different, but again I'm certain we'd be interested to know where the problem is. Keep in touch.

Hi Neil

Will do.

I have been advised before to leave the bike on compression. I'll certainly give that a go. I'm in the throes of getting an Alton electric start for the bike as I have arthritis. If / when I proceed with the Alton, is it safe to say thet the starting difficulties would disappear overnight ?.

Cheers

John

Permalink

Previously andy_marks wrote:

There was quite a discussion a week or two ago about attracting new and younger members. Take a look back through this conversation now and ask yourself; if this was your first insight into the NOC, would you come back?

Hi Andy

You make a very good point !. I am brand new to this owners club having only very recently bought myself a Commando having fancied one for years, and I guess in an ideal world comments should be kept as positive and friendly as possible, notwithstanding the fact that a little light hearted banter is generally perceived as ok by most people ?. We had a bit of bad feeling in the AJS and Matchless Owners Club ( to which I'm also a member)some time ago, and it reached a point that a very experienced elderly ex-Matchless company engineer decided he's had enough with the in-fighting and relinquished his membership, and the club forum has never been the same since....we sadly miss his marque expertise!. This can happen with new members also. If you dont mind me commenting so early in my membership, I would urge experienced members to be cognisant that what might seem to be "banter" to them, can be perceived quite differently by new, in-experienced members.......just a thought ?.......

Permalink

Previously John Pye wrote:

Previously andy_marks wrote:

There was quite a discussion a week or two ago about attracting new and younger members. Take a look back through this conversation now and ask yourself; if this was your first insight into the NOC, would you come back?

Hi Andy

You make a very good point !. I am brand new to this owners club having only very recently bought myself a Commando having fancied one for years, and I guess in an ideal world comments should be kept as positive and friendly as possible, notwithstanding the fact that a little light hearted banter is generally perceived as ok by most people ?. We had a bit of bad feeling in the AJS and Matchless Owners Club ( to which I'm also a member)some time ago, and it reached a point that a very experienced elderly ex-Matchless company engineer decided he's had enough with the in-fighting and relinquished his membership, and the club forum has never been the same since....we sadly miss his marque expertise!. This can happen with new members also. If you dont mind me commenting so early in my membership, I would urge experienced members to be cognizant that what might seem to be "banter" to them, can be perceived quite differently by new, in-experienced members.......just a thought ?.......

And this is help in trying to sort out a Commando then, If this machine wet sumps easy then the oil pump need looking at, or the oil seal are leaking in the timing cover, if you cannot get a good swing at the kick starter just try starting it on the left hand cylinder get that warm and do the same to the other side , then once warm it should start easier on two cylinders, but if you have nothing happing its time to go back to the drawing board , and start from scratch, and double check every thing you did, it may be just a wire some where that not making a good contact or something blocked up, somewhere . without seeing what amiss we cannot go much further, Yours Anna J

Permalink

Hi John,

Glad we are back on topic, although answers are not always straight forward and you sometimes need to widen it a bit.

Anyway, although I have a Mk 3, I removed the electric starter, putting in a blanking plate when I restored the bike. The engine was rebuilt by RGM in 1989.

I always planned to put the electric start back once I got too old or knackered to kick it over. That day is coming soon.

From reports, I have heard on the new Alton starters and the upgraded Mk 3 starters start well even from cold, without destroying parts on backfire.

I had problems starting my Commando last year. I checked the battery and found 11.8 volts!!!! Just charging isn't enough if the battery has had it. Got a new gel battery from BOM Battery's and as long as I free the clutch first, tickle the carb and empty the sump if not started in the last two weeks (In my case...All different) The she goes after a few kicks with full choke and first kick with no choke when warm.(+ a bit of throttle) But I always need to tickle the carb on each start. I call that my anti theft device!

Good luck and thanks for getting back. Always an anti climax if we never find out what the cure / problem is / was...

Permalink

In my experience, most non-catastrophic failures with Commandos tend to be a combination of problems.

A Boyer with low volts will be over-advanced and will kick back like a mule. Michael hasn't mentioned those symptoms.

If the oil tank can drain in a week then there is a problem with the pump. If the flywheel is dragging in oil then it will be very difficult to spin the motor fast enough to start it. An 850 Commando is harder to kick over than a 650 twin. Primary gearing is probably a factor here.

If the bike has been standing and the carbs needed cleaning then unless the main cause of that fouling has been addressed, the problem will return. It would probably be a good idea to drain the fuel tank, clean taps and filters (which unscrew with the taps...or at least we hope they do) and remove the tank from the bike to give it a thorough clean.

If water has built up in the tank, it will cause precisely this sort of problem if drawn into the pilot jets.

One more thought...please excuse if it sounds condescending...but are you using the choke correctly ? Just last week in France, a BSA owner was insisting that his choke was on when he pulled the lever back and off when the cable was slack...It's a common mistake for those not used to Amal type carbs. Lots of black smoke and rough running but M20s are much more tolerant of that sort of thing than a Commando.

You're probably going to need to go through everything in the end. It may be best to plan an overhaul of the electrical and fuel systems.

Permalink

Dear All

Thanks for the varied comments and an apology for the time taken to get respond (three children, working away etc).

I am adopting the advised approach of doing one thing at a time and then checking, which seems the only way to go given my inexperience. This is what I've tacked today:

1. Drained the sump. The manual says "small amount" of oil should come out but I basically emptied the oil tank.

2. Checked the battery, agan. It is showing 12.69v, so that should be enough? However, what I did note was that I got a kick-back at one point when kicking over.

3. Checked spark - elimination shows both leads are working and I am getting a spark from one-plug but not the other, so I suspect the next step is to replace the offending plug?

Also, and I know this is very daft but how do you tell if the piston is on compression.

Again, thanks for your help,

Michael

Permalink

Maybe this answer is a little simplistic but if you depress the starter lever slowly, you should feel a resistance when one of the pistons come up on compression. This is assumeing that your rings are in good nick and that the valves are adjusted correctly.

Permalink

Previously michael_sullivan wrote:

Maybe this answer is a little simplistic but if you depress the starter lever slowly, you should feel a resistance when one of the pistons come up on compression. This is assumeing that your rings are in good nick and that the valves are adjusted correctly.

Makes sense to me - thanks Michael

Permalink

Previously richard_payne wrote:

In my experience, most non-catastrophic failures with Commandos tend to be a combination of problems.

A Boyer with low volts will be over-advanced and will kick back like a mule. Michael hasn't mentioned those symptoms.

If the oil tank can drain in a week then there is a problem with the pump. If the flywheel is dragging in oil then it will be very difficult to spin the motor fast enough to start it. An 850 Commando is harder to kick over than a 650 twin. Primary gearing is probably a factor here.

If the bike has been standing and the carbs needed cleaning then unless the main cause of that fouling has been addressed, the problem will return. It would probably be a good idea to drain the fuel tank, clean taps and filters (which unscrew with the taps...or at least we hope they do) and remove the tank from the bike to give it a thorough clean.

If water has built up in the tank, it will cause precisely this sort of problem if drawn into the pilot jets.

One more thought...please excuse if it sounds condescending...but are you using the choke correctly ? Just last week in France, a BSA owner was insisting that his choke was on when he pulled the lever back and off when the cable was slack...It's a common mistake for those not used to Amal type carbs. Lots of black smoke and rough running but M20s are much more tolerant of that sort of thing than a Commando.

You're probably going to need to go through everything in the end. It may be best to plan an overhaul of the electrical and fuel systems.

Dear Richard - thanks for the tip about the choke. I don't think you're being at all condescending - the advice is appreciated. Cable slack on the amal carbs is choke on?

Best wishes,

Michael

Permalink

Previously michael_macneil wrote:

Dear All

Thanks for the varied comments and an apology for the time taken to get respond (three children, working away etc).

I am adopting the advised approach of doing one thing at a time and then checking, which seems the only way to go given my inexperience. This is what I've tacked today:

1. Drained the sump. The manual says "small amount" of oil should come out but I basically emptied the oil tank.

2. Checked the battery, agan. It is showing 12.69v, so that should be enough? However, what I did note was that I got a kick-back at one point when kicking over.

3. Checked spark - elimination shows both leads are working and I am getting a spark from one-plug but not the other, so I suspect the next step is to replace the offending plug?

Also, and I know this is very daft but how do you tell if the piston is on compression.

Again, thanks for your help,

Michael

1. To lose all of your oil to the sump in a few days shows the oil pump needs refurbising to restore its internal clearances. Your running oil pressure will be low until you do.

2. Your voltage test was not under load, once you turn the ignition on the voltage will drop as the Boyer takes some juice, once the battery voltage drops the Boyer will act up by going over advanced. The later MK4 Boyer and all the Pazons are more tolerant of lower voltages and are a must for NK3's with Starters.

3. New plug, then if still no spark swap coils to see if a coil is defective. Also make sure you have a dedicated earth wire from the head to the battery +ve terminal (there is one already down below on an engine stud but best be sure as you are relying on a path from the head to the crankcases), I had major problems with a boyer only firing one side until I did this, I also ran the boyer earth to the same piont on the head.

Permalink

Wet sumping is not always down to worn oil pumps. Although this is probably the most common reason, pump to crankcase joint is another regular culprit, but for some more possibilities, have a read through this thread, http://www.nortonownersclub.org/noc-chat/technical4-commando-forum/65493698?b_start=0#224696178. We have now cured that machine, it was down to incorrect drilling of the oilways.

Regards, Tim

Permalink

To check which piston is coming up on compression you can remove both plugs and them placing your thumb over the spark plug hole you will feel the pressure increase as you depress the kickstarter as both pistons go up and down together the other piston will have no compression as it is on the exhaust stroke ie. exhaust valve open. Having sifted through the advice given here, I would doubt that the valve clearances are the issue but you might as well satisfy yourself that they are correct. If your plugs are wet then the carburation should be good enough to start. The oil you drained out of the sump may have drained own over the time spent away but again, once replaced in the tank, should only be a temorary inconveience. That leaves the ignition. By swapping over various plugs, leads, coils etc you should be able to get to the bottom of it. Try connecting a car battery to ensure a satisfactory supply of volts (you don't say whether you are using the electric start) but make a proper job of the connections so you don't set the whole place alight.

Let us know how you get on. Contact your nearest local NOC branch for more free advice. Commando's are pretty crude devices and should run in the most adverse conditions.

Permalink

Hi. I've been through the electricstarter/electronic ignition/sprag gear replacement programme, and having struggled to get everything to play, the biggest improvement after all the mods was a Shorai battery to replace a new lead acid one that still struggled despite everything being set u properly. It wasn't cheap, but the bike starts well and there's no worries about a flat battery stranding you if you are dependent on the electric start.

Andy K

Permalink

Folks - thanks for all the advice. New spark plugs and I got it started last night.

Regarding the choke issue - I am pretty siure the choke is 'off' but I am noticing more smoke from the right hand exhaust. Any thoughts?

Anyway, thanks for your advice so far.

All the best,

Michael

Permalink

Previously anna jeannette Dixon wrote:

Previously michael_macneil wrote:

Folks - thanks for all the advice. New spark plugs and I got it started last night.

Regarding the choke issue - I am pretty sure the choke is 'off' but I am noticing more smoke from the right hand exhaust. Any thoughts?

Anyway, thanks for your advice so far.

All the best,

Michael

Yes you nothing to worrie about its just excess oil in the crankcases trying too find its way out its should burn off and run with no more smoke , my Manxman dose its after its been stud for a month after some revs its then burns off and it gone , no more smoke ,

have you try Bosch triple electrode I been running my 650 Manxman on them now for 3 years and I have not taken them out yet , starting is very easy and runs very nice and it runs cooler too, ask Tim green at Green spark plug.co.uk I am running on W7DTC witch is the same heat range as Champion N5 , But these have No resistors in them its a magneto ignition Being a Commando you need some with resistors in them so this will be a different plug number, Yours Anna J

Permalink

Commandos do not need resistor plugs, the only need to fit resistor plugs is if you have a TV display or you fit a Digital ignition system or a Sprax 3 Phase voltage regulator/rectifier which for some strange reason fails to regulate without resistor plugs.

 

Norton Owners Club Website by White-Hot Design

Privacy Policy