hello. all

having some trouble with my freinds bike and its got us all stumped

basically the bike is only running on cylinders 1 and 4, but if you disconnect the coil it will then start running on 2 and 3, plug the coil back in and it goes back to running on 1 and 4 again at idle or at revs. its also not charging the battery but this might be a sepaerate issue

we have so far

changed the coils 4 different ones in various combos,
2 sets of plug leads again in various combos
New plugs
3 different rectifiers
different carbs (but thefact it runs on all 4 but only in pairs shows its not fuel issue)
new battery
and the cdi off my bike which i know works fine

we are tottaly stumped

we have a feelng might have some thing to do with the speed restrictor in clocks? as that shuts off a coil doesnt it? maybe its stuck on or something?

try a new loom i would

wel thats all thats left to change lol - but we dont want to be changing the loom

speed restriction symptom as follows:
bike will NOT rev past 5.500Rpm in any gear/neutral or as it gets to 5K rpm it runs on 2 cylinders.

if this is whats been happening.. its a simple fix. just by-pass the speed limiter with a resistor mod (DIY instructions or full plug n play mod kit available from me)
ebay Item number: 190317557067

its only running on 2 from start up, doesnt change with revs -

k, which tells me its not the speed limiter.

"its also not charging the battery but this might be a separate issue"
> i think you need to investigate this.. its probably related and causing the problem

Sounds like a short in the loom to me. Start by checking the grounds and work from there. You know it is somewhere in the ignition circuit from the symptoms.

Try swaping over the pos and neg on the coils .

Are the coils well earthed to the frame same goes for reg rec battery and engine ect

right some more developments.

checked every thing possible on the loom with the multi meter couldnt find any thing wrong other than the stator/generator isnt putting out a charge.

as we where running out of ideas we pulled the engine out and removed the head as we thought the HG might have gone between cylinders 2+3, but nope head, gasket, bores and pistons are all in good condition only thing was the in and ex valves we really sutty and coked up on 2+3

we are totally stumped !!!!!!!!!!!!

new loom