Low throttle misfire

[fast pom]

My own carb question. I have cleaned balanced more than once but cant get rid of low throttle misfire . The bike 1978 GS750 2v has 850 wisico pistons +1mm oversize inlet & ex valves. The misfire happens at low speed steady throttle . Accelerates clean. I have striped the carbs so many times checked and rechecked all jets are clean mains are new. Also running Dyna ignition coils and leads. Any help please.

Have also posted this on OSS

[Steve]

You have "checked and re-checked all the jets", but have you dipped the carbs to clean all the little passages that connect them?

Did you do any re-jetting with the 850 kit? I don't know what might be necessary, but I don't think the stock 750 jets would be right.


Oh, and the carbs don't like being "striped". They prefer PLAID.

.

[tkent02]

How did you set the fuel screws?

[gearhead13]

I had to go from a 42.5 pilot to a 47.5 after I bored mine out. I had the same misfire at crusing speed. I still get some popping on deceleration, but much less.

[Don-lo]

Did you think about cam timing? Stock can be way off. We had a moderately built KZ1000 that was chattering the slides of 33 smoothbores because of bad cam timing. Degreeing the cams in completely changed the power: all good, all the time!