yz250f yoshimura pipe

[Blader]

I bought my 03 yzf250 and it floods rly easy.. im looking at the jetting and i notice most of them are way off. ex: the leak jet should be 100.. its 55!
why would someone change it to that? could it be because they put the yoshimura pipe on it? how does the pipe effect it?

Anything will help at this point
thanks

[Freak]

Are we talking just the can or the header pipe as well? Most bikes will not need re-jetted with just a slip on, if they do it is very minor change. The header pipe being changed is a different story and honestly, I'm not sure why that is. Has to do with air/fuel, the opening I think. As far as the leak jet, not sure. Could be someone was just trying all different kinds and then gave up and left it in there ? Maybe we can get one of the pros on the board to chime in on this one.

[pjg351]

Originally Posted by Blader

I bought my 03 yzf250 and it floods rly easy.. im looking at the jetting and i notice most of them are way off. ex: the leak jet should be 100.. its 55!
why would someone change it to that? could it be because they put the yoshimura pipe on it? how does the pipe effect it?

Anything will help at this point
thanks

They change the leak jet normally to get a better squirt of fuel into the Carby normally. Check your float level is right first, that could cause it to flood.

[Blader]

i messed with the float and it was letting a little too much in.. but this might be a dumb question but how can i tell if they changed the header? im not sure if its just a slip on or not..

[Yves Edge]

I would leave the 55 in it. If you go to a 100 you'll get a huge bog when you wack the throttle open. If its rich, change or check the pilot, main and needle position. The float level being to high might be some of the problemm. What pilot and main does it have?