M1 rough running

[Webby]

My M1 is running as what can only be described as RUFF!

1 & 3 are ok but 2 & 4 I can hear the splutter.

Runs ok when warmed up but shed loads of exhaust somke. No oil in the smoke as confirmed by tissue over exhaust and compression test and plug wet test. 3k revs and it is lumpy. get to 6k and it smoothes out a little. get to 10k and it seems ok across all cyls.

tickover it hunts all over the place.

Had this dynoed, fuel injection setup and mapping done. At a complete loss now as compression is the same on all cyls.

Back off from medium to full throttle and it trys its best to tip you over the tank before recovering.

I'm sure this is down to the "splutter" but what the heck is it? Valve clearances checked, filters all spot on, plugs all new.

Ideas please?

[DoodleBug]

HT leads, coils?

[Webby]

Metered and all changed. Still the same. Thanks for the response though. Appreciate it

[DoodleBug]

Maybe reg.rec then? Saprk is breaking down when the engine isnt spinning up much.

[Webby]

Thanks. I'm out to the garage shortly to check. Haven't done that yet.

Do they break down under load at all? Should I check when hot? Can I expect to find same readings at idle as full chat?

I know coils sometimes break down when under load and know how to meter for that but reg or rec. Not sure here?

[DoodleBug]

Only real test I know to show that one is on its way is to rev the bike with the lights on. If the lights brighten and dim chances are that the regrec is okay. You will know soon enough when you end up with a dead battery!

[Webby]

Got plenty of them all charged so a flat one won't hurt. Cheers M8