VF1000 F2F - Stuttering, Misfiring at speed.

Hi, Maybe you can help…

My VF1000 when accelerating in top gear from around 70mph starts to slightly misfire, or stutter, almost like a cylinder is cutting in and out.

I’ve checked the plugs and electrics (not the coils, yet) and cant find a problem. I thought maybe there was a problem with the fuel pump but, again, it seems ok.

Any ideas ? Could this be due to a perforated diaphram in a carb?

Look forward to hearing from you.




It’s the carbs… Might be a diaphragm , but it’s more likely to be muck and lacquer deposits from the fuel… These carbs do not work well when dirty… I’ve had mine apart 3 times for the same problem as you describe. I found 2 diaphragms with pinholes - replaced… The float heights were WAY out - reset to 7.5mm… Finally fixed the problem by stripping completely and thoroughly cleaning every orifice with carb cleaner and compressed air. Rebuilt carbs with Keyster rebuild kits (NRP Carbs, Manchester - 0161 832 8646, Ask for Andy, say that Jeff Mitchell sent you and he may well treat you kindly…)

Also - for confirmation of the fault try searching through the USA Sab/Mag/Interceptor Forum - you’ll find so many hits on carbs that you’ll wish you hadn’t looked…!!

All the best


Sunny Scotland - North(ish)
VF1000FE - (MB6 - '84)
XS1100S - (5K7 - '85)

had the same proplem on my vf,turned
out to be the pulse coils,one was breaking
down under load.hope this helps.