off idle roughness with a kdx200 sr

[jabman]

Hi all,

ive just been doing up an old 1990 kdx200 sr with a rebore, new piston, clean carb, new KIPS etc and now for some reason i can start it with the choke, take it off the choke after a minute and tweek the idle screw for a stable tick over but when you start to turn the throttle the revs shoot straight up to about 3k revs. It does this in neutral or in gear with the clutch in?

Im guessing this is a carb set up issue but i have never set a 2 stroke carb up before and dont even know where to start for this problem?

Thanks in advance!!

 

[reepicheep]

The little chart that came with the boyesen reeds was really helpful for me to try and figure out jetting.

The big breakthrough for me was getting over the idea that jets are related to RPM, they aren't, they are related to throttle position (though a throttle position can be problematic at one RPM but not another).

Mess with one thing at a time, and assume nothing, and don't forget to adjust the needle clip position. Resign yourself to the fact that you will remove, tweak, and reinstall the carb something like 20 times before you are done...

 

[jabman]

yer the only mod i have is carbon fibre reeds im using the stock 28mm carb.

do you think lower or higher for the needle seeing as the revs shoot up with only a tiny bit of throttle? also when slowing to a stop the revs go down as i close the throttle and brake but when the clutch comes in the revs shoot up (the throttle has been closed since i started the slowing down)