Hello

I have a ty 250 mono that has a problem when accelerating. When i accelerate it will pull and sound normal and then it will suddenly stop accelerating any further (before the revs get to its max) and start making a strange noise possibly misfiering but im not sure, it makes the same noise when cruizing in lower gears when there is not much load but i think that may be normal.

Does anyone have any ideas what could be causing this?

Cheers Lewis

Is the air filter clean?

How is it when it's fully warmed up? Mines like that till it's warmed up.

The air filter is clean and it does this when it is hot.

Cheers Lewis

Its probably dieseling,Yam mono's were prone to this.I stopped mine doing it by carefully going up on main jet size till it was just a tad rich - but ran a treat without knocking at all. And I'm almost ashamed to admit the jet was one I found in a Suzuki moped carb,which I gradually reamed out with Mig welder nozzle cleaners - crude,but it worked.......