Norton 650SS starting problem

Its likely that one of your pickups, lead  plug,or plug cap are faulty or not faulty but the wrong type. A mag bike with this problem can start on one cylinder ,but only if the mixture on that cylinder is nearly correct. Its also likely that the mixtures are incorrect anyway or the fuel has degraded if older than a couple of months.. If the Mag has a very small points gap this can result in sparking on one cylinder but not the other as the mag cam rings are often unequal . Coil ignition provides a better spark at Kickstarting speed. Half the fun of owning these old clunkers is the satisfaction when you get it running like a sewing machine ,  eventually ,   Have fun.

We seem to be in a change point with fuel. Up to recently much of the uk could buy Esso Synergy plus fuel that despite having E5 stickers on pumps and  could have up to 5% but did not have any ethanol in it . Other premium fuels were not so  forthcoming about what was actually in their pumps. The disribution of Esso fuels has changed and we think it now probably contains ethanol. I would still recommend using a premium grade fuel and try to limit the amount of water vapour that can enter your tank ,or use an additive or drain off and put in the wifes car !.Todays fuel burns a bit weaker and reputidly faster than the real deal.So carburation and ignition timing may need a tweek.Also some paint finishes will disolve if you spill on it. Half the cars in the country are heading for fuel systems breakdowns ,but no one likes to admit it.Just my opinion.

I used to cover the tank breather with tape but then used a fridge magnet (after allowing the fuel to settle ), I did not think it would be effective but after running out of fuel a couple of times , I am convinced!!

Hi Roger.

Further to Robert's comments I would suggest removing both HT pick ups from the magneto to check if there is any oil in there limiting things plus to check that the carbon brushes are in good condition and long enough to do their job. A clean of the slip ring wouldn't do any harm but beware of using your finger to hold the cleaning rag in there or you'll get a shock. Ask me how I know! Plus check plug gaps if you haven't already. Could even be one plug is now defunct and in need of changing but just switching them round as you test should confirm that. They don't last forever and even new ones sometimes have issues apparently.

For what it's worth I used to run my 650SS on the standard fuel but found that a change to the premium grade (Shell in my case at my local service station) made the engine much more responsive so that's what I use now in spite of its extra cost.

Hope you can get it sorted soon.

A properly sorted 650 ss is a very lively machine and a great all round package , enjoy!!

I fitted a Thorspark electronic ignition to my Atlas. Fits straight into the KF2 mag and once the original screw-on cover goes back on on you'd never notice it was there. It didn't have a spark when I got it. Now it has two big fat ones and it never needs adjusting. Cost £150 +p&p. Incredible piece of kit.

I got it from Sussex Motorcyles. 

1961 Dominator with single Amal carb.  Started from cold on 2nd kick after a year (with appropriate fettling first of course).  Runs well.  Starts well from cold (full retard, full choke, tickling), BUT a pig to start when hot or even warm.  New fuel, good spark, plugs a nice colour but noted that after several minutes of fruitless kicking the plugs are bone dry. Is this a carb issue do you think?

Hot starting problem is classic symptom of condenser (capacitor) failure.  Get a replacement from Brightspark.  

I would like to ask Graham Zimmatore how long a time has he had his Thorspark fitted to his machine as I have a tale to tell about the one, I fitted to the K2f magneto!!

Hi Paul,

I fitted the Thorspark into my KF2 magneto about 5 weeks ago. What's the tale you have to tell?

Hi Graham. Are you sitting comfortably, then I'll begin!

Please note this is the abridged version!

 I fitted the Thorspark to my Matchless G9 at least 5 years ago and it transformed the performance noticeably easy starting, lively acceleration increased mpg. all of the boxes were ticked one happy bimbler!

Then it all started to unwind when the engine would start no problem only to start to fire on one cylinder within a few hundred yards, ease back on the throttle and firing would recommence on both cylinders, all would then  be well throughout the journey.

After a season of this misfiring I approached Chris Williams at Sussex Motorcycles who sent to me a new Twin coil unit to replace the original FOC.

All went well  for a while until deja vu crept in and off we go again.

Phone call to Mr Williams who suggested I put a direct earth lead from the cylinder head to the battery "voila" solved, for another season.

Guess what? Misfire rears her ugly head once more .I'm smouldering by now!

Thinks maybe another earth lead to the battery from the other cylinder head could be beneficial, nothing to lose. This wheeze lasted a wee while until having reached the Isle of Man ferry terminal at Liverpool just recently, the engine refused to fire on both cylinders unless I swapped both HT leads over from left to right and the left pot, plug cap "resting" over the spark plug.

At this point still at the terminus in Liverpool a call was made to Mr Williams for him to send over to my Hotel in Ramsey a new coil, this duly arrived within 24hrs. My euphoria was soon wiped away when no improvement to the misfiring was forthcoming, the new coil was no better.

Are you still with me?

The Isle of Man trip was a disaster as eventually the engine ignition petered out whilst attending the international trials sections and the Matchless had to be recovered from the side of the road and eventually carted back home on the mainland which is another saga in itself!

Another phone call to Mr Williams has resulted with him asking me to send the trigger unit electronics back to him for assessment.  He should be in receipt of the component as I write.

One aspect of this long story  is the fact that the engine will run on one cylinder until the ignition switch is turned off or it runs out of fuel either way.

All through the problems that I have had with the Thorspark system I have covered the HT leads with 2.6mm silicone sleeving, routed them from any source of possible earth tracks, wired the whole system from stem to stern anew and consulted one or two oracles who in the end could not help me with my problem.

I hope that he Trispark I have purchased for my Combat is compatible with two cylinders!!!

That's quite a story Paul. I feel for you mate.

Well, so far I'm pretty pleased with the Thorspark I fitted.

The bike has a brand new battery and I've ensured that there are plenty of earth connections to the engine and frame.

Time will tell I guess!

Hi Graham.

I posted my experience for two reasons.

1) To show that the Thorspark has acted up in the way that it is doing and that I cannot believe that my experience is unique to me, therefore.

2) In the hope that someone will read this thread and come up with the definitive answer.

The new battery that you have fitted is a good move, so too the earthing arrangements.

I have an Optimate connected to my battery at all times whilst in my garage which takes good care of it. Due to my low milage per year previous batteries would deteriorate rapidly for me to have to buy another one before I would venture out especially with the electronic ignition dependent on it.

When the Thorspark worked the bike was a joy to ride so I do hope that you have a trouble-free experience with yours.

When Mr Williams comes up with a solution, I'll let you know if you like.

Regards. Paul.

Fitting a modern electronic ingnition gizmo into a 57 year old magneto - what could possibly go wrong? The fact that it works at all is a bloody miracle IMHO. Personally, I think it's got a lot to do with the condition of the mag you're fitting it to. 

The KF2 mag on my bike appears to be in ok nick mechanically, it just didn't produce a spark, most likely due to a dud condensor, which would have meant pulling it out and having it reconditioned. I was going to do that but a friend of mine suggested contacting Chris at Sussex Motorcycles instead. 

The unit fitted in nice and snug and the instructions that came with it were clear and concise. It saved me a lot of work, i.e. having to open up the timing case, remove the mag, send it off to be reconditioned and paying circa £500 to boot.  

The Thorspark kit only cost £150 + £10 p&p, arrived 2 days later and took me a couple of hours to fit, and to be honest I'm NOT very good with electrical stuff. I found Chris to be a really helpful guy and very old school - he even called me sir! Don't get much of that these days (lol)

The benefits of this system over a standard mag are: a) the dual spark, b) you can change over the HT leads and it makes no difference, c) doesn't require points adjustment, d) fit and forget.

A new or good condition battery and copious double wire earth leads are necessary with these units and the automatic advance retard and centre spindle have to be in servicable condition, also, the cam ring they supply with it has to be fitted to prevent the screw on magneto cover from shorting it out. It sounds tricky but it's just common sense really.

Hi Graham.

I recognise your images!

I contacted Chris Williams earlier this afternoon to see if he had had time to check over my trigger unit.

He found it to be working!

I asked him how old my unit was and he told me that he still has my original e-mail order dated 2011! That was a wow! moment I can assure you, time flies. 

Any way it doesn't explain the misfiring and the eventual demise of the spark ultimately over the last number of years as I haven't changed anything on the Matchless only the oil since fitting the Thorspark.

I'll refit the trigger unit once it arrives back and reposition the dual coil under the petrol tank behind the front downtubes instead of under the seat as there is less chance for HT shorting around this area.

That will be my last throw of the dice with this unit as my tether is just about worn through with little else in my locker to fall back on.

Were's Paul Daniels doppleganger when you need him?

I placed the coil unit in between the oil tank and battery box