Tuning help

[EJ Racing 07]

Hello everyone, so i picked up 08 250 that has a motor built by CT with a 300 kit in it. It has a Vortex adjustable cdi, full GYTR exhaust, Mikuni Sudco carb. I'm running 110 through it, my question is that it pops through the exhaust a lot. Do I have a jetting issue? I'm use to tuning our two stroke, I have tried running on all 9 cdi setting and it seems to act the same. Thanks for any help!

[mxdad423]

Is it popping on Decel? if so there are a few things it could be, more than likely it is a little lean, but it could also be an intake air leak, or exhaust leak, all 3 will make it pop on Decel, I just had similar issues with ours, but it also would not idle, I went up on the pilot jet 1 and up on the main 1 size and it idle'd perfect and the popping went away, so I would start with some jetting first. if that doesnt work, spray some starting fluid around the carb and intake while it is idleing, if it has an air leak the rpm's will go up when it picks up the starting fluid. Hope that helps.

Kevin Smitley

[EJ Racing 07]

Thanks Ill check into that, it pops every so often at idle but dose it the most under power

[hwf-racing]

I could never get the Sudco carb tuned right. I swtich to the FCR and all of my issues were gone. Good luck.

[EJ Racing 07]

Originally posted by hwf-racing
I could never get the Sudco carb tuned right. I swtich to the FCR and all of my issues were gone. Good luck.
What size FCR are you running?

[hwf-racing]

32 fcr