I just installed an Area P full exhaust on my 08 250R as well as a Dynojet kit. I was hoping the recommended settings would work but...of course not. It is running poorly below 4500 RPMs. I have now moved the needle lower and it seems to be running fine now.

However, that is not what this post is about. After removing the spark plugs, that were used with factory settings, one side appears to be running lean while the other running rich. I have not tried to sync the carbs as none of that has been touched. I do know that the factory settings for the fuel/air screw is different for each side. Could that be the reason one side shows rich and the other lean? Should I have the carbs re-synced?

Any advice would be appreciated.

Charley

 

I do not have an 08 manual handy. The pilots set points are normally different for each side? What about the Main needles since you lowered one due to being too rich? Are they different as well? I know, just more questions to add to the mix of things.

 

If you're not expert in setting up carbs I'd get the bike set up on a dyno. The carbs should ideally be re-synched anytime they're disturbed. It only takes a couple of minutes once the tank's off.

The fuel/air screw is only effective at idle and a little way off idle. The standard way to set up carbs is to select the correct main jets first so that the mixture is right at full throttle. Then you can select/adjust the needle for correct part throttle mixture. After that the mixture screw can be tweaked for optimum idle. Make sure that the motor's fully warmed up before making any changes.

Rob