650SS

Sounds like a good place to start would be to learn how to maintain and tune motorcycles.

A lot of people don't like it when I give answers like that, but it is the truth. If you can not figure out how to trouble-shoot and tune a British bike on your own, then you don't have a lot of business owning or riding one as their nature is to need more frequent maintenance than current consumer goods.

Instead of asking us if you should check the ignition timing you should have already done it. Also you should have already checked all electrical connections for your ignition to see if one of them is failing when it gets hot or with vibration. Also you should have thought to try and borrow a spare Boyer black box and swap it in, which is called "The Process of Elimination", yet one more basic troubleshooting skill.........etc. Is this Norman White's old 650ss cafe by chance?

Alloy barrels don't seem to have been a popular item. Worth checking out why.

Ben - remember we all had to start somewhere. And we need new Norton owners - who often don't have the opportunity or the need to maintain their own modern vehicles.And diagnosis is far more difficult than actuall fixing an obvious problem. We've all spent many happy hours optimistically fixing things that weren't broken in the first place.And he might not have access to a spare Boyer!AnywayIf the engine starts then the timing cannot be far out.If the engine stops then it must have run out of something (or got far too much of it).That might be air. Not likely but possible. Is the tank cap vent clear or does the running engine create a partial vacuum after your 15 minutes? The tank cap will hiss when removed.It might be fuel. Clogged filters - not likely, but maybe the motor runs mostly on what is in the float chambers for a few minutes until it is starved.It might be valve gear. If the clearances are too tight then it is possible that that they close up completely when the engine is hot.It might be sparks. Boyers are allegedly sensitive to low voltage and revert to full advance. If the motor is already running but charging is slow it ought to run OK on full advance - but wouldn't be happy trying to re-start. My guess is the Boyer.p.s. this is the second attempt at this post..

On occasion some might consider Benjamin blunt but he is usually right! Although a sometimes amusing way to pass the time, trying to correctly diagnose the faults of an erratically behaving Norton via an on-line forum is difficult. That said, novices in the Norton brotherhood often need help. Those of us who think we know something about Nortons should be ready to ride over and help when possible. Maybe the club could have a register of members prepared to do this?

For what it's worth, I agree with David and would check through the electrics in general and the Boyer in particular.

As for alloy barrels I don't believe them to be unpopular, just rare, expensive and in some cases not looking much like the originals. But if someone has some in 650 or 750 size going for a fair price, I might be interested!

I had a similar problem recently on a Commando with a new Boyer. It just lost power after a few minutes. I had new coils but changed them anyway and the problem was cured. I have not had a chance to test the first set of coils but suspect a problem there.

Coils for use with Boyers have to be in a resistance range. The Boyer instructions tell you the resistance needed. Those aftermarket Harley-Davidson coils, like Accel work well if you get one with the correct resistance.

Of course, Lucas K2FC magnetos work really well too, if you have one .

Try using the Champion N3C spark plugs as the N4 would run a bit hotin the 650 and 750 motors. A very well known Norton dealer recommends N3's for Norton twins.Use a gap of 0.025. Also try the NGK B8ES plugs as they area really good plug for the Norton twins. I run all my 600 to 750 engines on either N3's or B8ES spark plugs. You could also try the Champion N6YC with the extended nose.

Stay with the club Malcolm as we are not all as offensive as Mr Gradler, and it really does not matter how experienceed or inexperiencedwe are, there are members out there whose knowledge and experience will help with what you may think is a difficulty but to others is simplistic.

Keep asking the questions!

Good luck with your 650SS

Regards, Paul

This 'engine dying' problem may be due to something as simple as the battery not giving the Boyer set-up enough volts to run properly. The early Boyer modules did not like running with less than 12 volts.

Also, when a battery was low, a nasty kickback or short engine run could also happen.

Checkout your charging system and make sure that your battery is getting enough juice to keep the Boyer active. I would put money on your alternator not giving 100%. This could be due to a broken wire in the charging set-up. Have you lost a wire off your rectifier?

This is probably to simple to be the cause of your problems, but, how old is the battery, and is it holding a full charge? The stupid design of the Boyer system (Fully advanced ignition with a poorly charged battery) is a great way to cause knee injuries, when it kicks back!

Hi Malcolm

The most likely causes of your troubles have been well covered in all the other replies. However, I had a similar fault a while back and I traced it to the Boyer unit. It turned out that I had placed it (between oil tankand battery box) where it was not getting a decent cooling air current.

The importance of getting a coil with the recommended resistance has already been mentioned, it will be about 3 ohms. If the resistance is lower the current through the coil will be higher, resulting in the Boyer unit and the coil overheating and eventually one or the other will give up the ghost.

P.S. Most NOC members will be glad to offer the benefit of their experience to anyone who wants it. Otherwise, what's the pointof the Forum?

Pjm.

Hi Malcolm, hope you DO stay with the club - rest assured there aren't too many arrogant sods like Benjamin here but all clubs have to have at least one - It's in the rules! As David says, we all had to start somewhere so it's non-productive to slag off someone just because they don't appear to have much knowledge of their bike. No-one knows it ALL - except me of course!

Just tinker and see what happens - that's how we learn. It's not likely that you'll blow up the bike or yourself!

Cheers, Lionel

4ah is a bit on the small side for a coil ignition bike. I use a 5ah on my magneto ignition Norton. Wouldn't want to go any smaller really. Gordon.

I had this exact problem with my 650 mercury. The problem was traced to the Boyer unit. They had a batch of units which had a faulty transistor. I had it replaced under warranty without a fuss despite the unit being out of the warranty period. As a precaution I changed my coil to a Boyer dual fire one with a higher ohm figure (4.2). The original was at 3 ohmsand the tech chap at Boyer suggested a higher ohm figure would put less stress on their ignition unit.

My T100R Daytona had a Boyer fitted, and the battery was giving a full out put. All my P11's and N15's had the Lucas 2MC capacitors so i did not notice, as i used the same battery in my P11 and the T100R.The T100R went onto full advance after about 5 or 10 minutes of running. It spat back, and i just about managed to get it home. I fitted a new fully charged battery and it was running perfect again. The Pazon ignitions run on a much lower voltage, so if you are replacing the Boyer try one of those. I have one on my single seat P11 and it runs gang buster.

This whole thread is another thing which makes me very wary of Boyer ignition systems. I have always found that Joe Lucas points and condenser systems work very well if they are in good condition and properly maintained. By properly maintained, I mostly mean that the auto advance has to be oiled from time to time, not given a hopeful squirt of WD40 which does nothing good at all. I did have a Boyer on my Commando, but I put the points back after having serious starting problems with a low battery.

Previously wrote:

Hi All,

I have a Dominator 650ss, it has had a lot of work done to it and is beautiful to look at and is in the cafe racer guise but has retained the original 650ss engine and frame which match.

Since i purchased it i have had a number of problems which i have been sorting out slowly.

1. headgasket blew first time out, repaired by the vendor. It has an alloy barrel and needed a proper copper gasket in there.

2. it has 12v ignition boyer type with dual single fire coil. and every time i ride it it will run for 10-15 minutes and then splutter and cut out, I started using higher rate fuses as usually as soon as i put in a new fuse it would run fine again however now the fuse has not blown but after 10 minutes it spluttered and cut out but will not start again.

Also previously after it had cut out and got hot it would not idle and would pop and splutter and cut out but would always start again when cold.

I have N4 plugs and have just put new HT leads on.

I'm getting kickback and it ran for about 1 second and died and will not start again. i have flooded it, and when i did i got a lot of kickbacks so i have spark and compression.

Could the timing go out or where should i start with this.

any help much appreciated.

mal.

Hello Right I would like to say something here first what year is Your Nice 650ss , As Machines From September 1961 to September 1966 all had Lucas K2FC magnetos fitted And they are the best of the Lucas mags for road use , But BTH made a better mag ,and today they make a magneto that is has electronic trigger this mean it has no points and as a automatic advance and retard and these are 10 times better than boyer As the bike with have its own ignition that independent from the battery and the bike with start and run with out a battery , just like the old magnetos but with bang upto date electronic magneto system so See www.BTH.co.uk , they cost about £600 but you fit it and forget it it works well ! yours Anna J dixon Ps keep with the Club and us nice lady riders

I have fitted one of those BTH magneto units to my 1966 N15CS, and it does run really well. I will also be fitting one to my Dominator 99wide line cafe racer. I was going top fit one to my 1963 Atlas Scrambler but for it to be authentic I am going to fit the proper Lucas K2F. I also found that when one of my P11A Ranger 750's was fitted with a Boyer it did run much smoother, but here is the kicker. The motor when it had the Lucas 6CA CB assembly and an A/R unit 54425657 unit did have much more get up and go, but the Boyer is a fit and for get unit. You pay your money and take your choice.

Me too Gordon! In the first'revision' of my early 99 rebuild, when I wasn't happy with thecoil/distributor system, I used the K2F from my 1955 88. (I'd sold off the frame & tinware) I didn't do anything to it, just cleaned the commutator with a meths rag - didn't it give me a belt just turning it by hand! Live & learn eh? I still have it but will be going with the coil ignition for authenticity and Concours. Although the Mag is worth a fair bit of money, I might just keep it as a backup!Cheers, Lionel

Previously wrote:

Previously wrote:

Hi Malcolm

The most likely causes of your troubles have been well covered in all the other replies. However, I had a similar fault a while back and I traced it to the Boyer unit. It turned out that I had placed it (between oil tankand battery box) where it was not getting a decent cooling air current.

The importance of getting a coil with the recommended resistance has already been mentioned, it will be about 3 ohms. If the resistance is lower the current through the coil will be higher, resulting in the Boyer unit and the coil overheating and eventually one or the other will give up the ghost.

P.S. Most NOC members will be glad to offer the benefit of their experience to anyone who wants it. Otherwise, what's the pointof the Forum?

Pjm.

Will check the coil resistance and battery voltage.

It Is a very tight fit under the seat hump and

Just been charged but it is suspect and has no

Amp hours marked on it. It's not a sealed battery and looks old.

What amp hours should I be looking at.

I found a new one that will fit but it's only 4 amp. Is that enough.

Once again thanks everyone for all the very useful help and advice.

Hi Malcolm

If you want to check your battery you should top up the electrolyte to the indicated level with distilled water then put it on charge.

A simple battery charger doesn't give you much control over the charging current but check after about thirty minutes that the battery isn't getting hot. Keeping charging until it starts gassing and you will see bubbles rising to the top of the electrolyte.

If you have a hydrometer check the specific gravity of the electrolyte, it should be around 1.250 to 1.280 when charged.

Finally, with the battery on the bike, check and note the battery voltage with all switches off. A good reading will be about 12.5V. Next turn your headlight on.The voltage shouldn't drop below 11V even if you leave the lights on for 5 minutes.

A 4 ampere-hour battery should , theoretically, supply 4 amps for 1 hour or 1 amp for 4 hours. It should be alright if your bike charging system is in good nick, but if that fails you won,t get very far.

pjm

Kickback usually indicates the timing is out. Check the ignition timing first as it's easiest. Always start any diagnostic checking with the simplest and cheapest components first. Don't assume that something expensive has happened. Try to check and change only one thing at a time so you can pinpoint it if you got it right. Not what I tend to do, which is change several things at the same time, fix it but not know what was at fault! It's OK - I've done this with cars, bikes, computers and electrical items! ("Do as I say, not as I do"!)

As Alan says - be methodical. I don't think I'll being fitting electronic ignition anytime soon, although I used to fit them to cars in the 1970s and 80s without probs - except for the one I put on a 1969 Bedford Dormobile which filled up with water due to a) not being waterproof and b) being fitted inside the front just below the 'bonnet' opening. Had I realised I would have sealed everything with silicone sealant. Incidentally, clear silicone, at least, is a good insulator up to about 25kV that I know of. I'm told it's OK for up to 100kV. Scary eh? A TV engineer fixed my old colout TV when it started arcing HT to the chassis (The symptoms are a loud crack and the picture blinking on & off!) The TV is still working but not used now we have a large flatscreen. No probs with vehicle ignition HT so it might be something to bear in mind if you have a leakage from your magneto, for example.

Good luck and don't forget to tell us when you find the fault(s)

Lionel

PS. Re: kickback - it can be running weak or have an airleak at the inlet manifold, of course!

I have the same bike with similar set-up (assuming yours has an alternator). If the battery is not fully charged on mine, (I now keep it on trickle charge) the bike will start from cold but after a while the plugs foul up on tickover due to battery not fully charged and providing weak spark. Engine will then cut out and become difficult to re-start.

Hi Peter, yours definitely isn't right. Once the engine is running, even on tickover, there should be more than enough juice from the alternator to provide the small current demanded by the ignition. You either have a current drain, faulty alternatoror faulty wiring somewhere. Once a bike is running the battery is almost superfluous. You should only need it for lights.

Cheers, Lionel