Hitchcocks Forum

My 500 bullet (classic engine nestling in a 53 frame) was always a poor starter. During a recent home service, me and a mate decided to check the ignition timing. Using Hitchcocks tool that screws into the spark plug hole, we discovered it was firing at dead on TDC. We advanced the timing to 8mm before TDC as recommended in the manual. This resulted in rather vicious kickbacks so we retarded it a touch to 5 mm. It now sounds different and not as good. Before it had a deep thud on tickover and was quite baritone as I plodded through town. Now its quieter and the deep thud is much less, with a higher pitch crisper note when on the move. I prefered it before but I guess its now as its supposed to be and it does start much easier. Can anyone explain why it now sounds higher pitched and more raspy with the ignition advanced?

8mm? Shouldn't that be 0.8mm?


Theres another similar thread running with good info

I think you've advanced it far too far. Should only be 0.8mm or 10 degrees.


Tony R

 Chris,


      8mm is for full advance but with the single Enfield it is too difficult to hold it in full advance when setting the timing so it is set at full retard.


    

Hi Chris Tindall------to answer your question }   Because you've miss-read the tech. info. old mate !!---- Yes, that should be --0.8mm BTDC ------  which to the untrained eye does seem like it's at TDC.( about 0.032" ). Put it back to where it should be and look elsewhere for the bad starting. Ignition timing should really be done at full advance for best results------ this is where the engine's performance will spend most of it's time, and also allows for any mechanical wear in the auto-advance, weight stops etc.  Our hosts sell a very useful tool for just this purpose. Incidentally, that timing tool screws in at an angle onto a piston that hardly seems to move on the last 10 degrees of rotation anyway. Result is an almost impossible-to-set situation.  Have you considered fitting Electronic Ignition ?? Not to everyone's taste but a proven item over the years and maintenance-free. 

Ah, I'm sure he said 8mm. I've looked at the manual and yes of course its 0.8mm. I have moved the backplate to the right a touch and the thump has re appeared. It seems we messed up, thanks for the advice everyone