Intermittent starting issue

Give the points a clean - they often develop a fine oxide film when new or unused for a while.

I'm with Gordon, Sounds like a temporary loss of sparks. I have an old Colourtune plug for this type of issue.With it fitted you can see the quality of the spark under running conditions or if the spark is missing.You can then eliminate other suspects and focus on the problem.Keep an open mind though .Mag earthing brush, shorting cut out button wire? , A mouse nest in the air filter?!!.

If you had your magneto reconditioned by these people and their coil winder, then I suspect thats your problem.last year after spending over £300.00 I was left with a mag whose armature dos'nt run concentric.Impossible to get the chain tension right but it's not their fault. Nothing to do with them.

I did 20 miles today and had some intermittent issues with the Dommie. Three times it cut out when idling in traffic, and on the last time I could not restart until it took 50 yards in gear to bump start down a steep hill to get it going again. Then it ran fine. So now I have a problem. What's the issue? Will it do it again? Will better fuel sort it out? I'm running-in new pistons.I've re-fitted the magneto (K2FC), reconditioned recently by Brightspark.One other symptom is that when starting from cold it seems reluctant to fire up at full speed for the first minute or so. I realise I have just fitted a new pair of KLG plugs (B6PS I think) but the odd slow starting has not altered.I just squirted isopropyl alcohol spray through the pilot circuits and they seem to be clear as far as I can tell. The tank fuel tap and supply hose are clear.

Hello Now thats where your problem is with these NKG B6ps it the wrong type of plug for a Magneto you need Bosch W7DTC there made for ethanol fuels and you find it wil start easy I been justing these for well over 3 years now and had No More problems with my 650 at strating , sometime after a good ride you find that this E5 fuel will dry out fast the float blow and its then hard to start , so try fuel cat , hope this helps yours anna j

Better still, try some Champion plugs and BP Ultimate Ethanol free fuel. Why would anyone wish to put a solvent into their tank, knowingly?

Better still, try some Champion plugs and BP Ultimate Ethanol free fuel. Why would anyone wish to put a solvent into their tank, knowingly?

Hello I run my bikes on Champion plugs for many years but Now Bosch Are a Lot better and more reliable , than any thing else cannot match them , yours anna J

Previously David Cooper wrote:

This evening I cleaned the points, checked the gap, changed the plugs back to the pair that worked fine before - and it was still reluctant to start. It fires for a few strokes and then dies. I know - if there is a spark (and there must be if it fires for a few cycles) then is must be a fuel supply issue - so I'm talking myself into believing the mag is OK. But, sadly, it looks like RITA will be recommissioned tomorrow. Shame because the mag on the 16H is excellent so I had a ride on the single tonight instead. More work and doubtless more mess.

David,

Just a basic thing but have you checked that the petrol cap breather hole is not blocked?

regards