Help needed! high revs lumpy run?

Can anyone offer any advice???

Have just had lots of work done to a 1979 KZ1000ST, head gaskets etc. It was running wierd and rebalanced carbs and found a small hole in vacuum tap diaphragm, ok, much improved but at aroun 5000-6000 revs it runs lumpy and a little hesitant, air filter ok, plugs new (in good condition), any body got a clue??? possibly points???

longshanks wrote:

Can anyone offer any advice???

Have just had lots of work done to a 1979 KZ1000ST, head gaskets etc. It was running wierd and rebalanced carbs and found a small hole in vacuum tap diaphragm, ok, much improved but at aroun 5000-6000 revs it runs lumpy and a little hesitant, air filter ok, plugs new (in good condition), any body got a clue??? possibly points???

Yeah, it could be the points. Have you replaced them? If they're original, the springs may have weakened, allowing the points to "float" and the timing to shift around a little bit at higher revs.

Cheers for that, checked they're good, as is the ignition advance, scratching head, it occurs at around 5000 revs and it is slightly chokey? talked to my friend and we reckon the only thing to do is back to the carb balance, what say ya?

Cheers for that, checked they're good, as is the ignition advance, scratching head, it occurs at around 5000 revs and it is slightly chokey? talked to my friend and we reckon the only thing to do is back to the carb balance, what say ya?