Jetting With R&d Power Bowl?

I just switched to blue after many years on a CRF450. I'm looking to clean up the bottom response on my new 07 YZ450F. I'm installing a R&D power bowl today and would like to address all the carb issues at once. All jetting and exhaust is stock. Fuel screw is 1 1/2 out. I race MX and all the tracks are at sea level. It's hot in the Northeast, 95 yesterday but most weekends are around 85-90. The R&D has the adjustable leak jet and a different spring for the AP instead of the oring fix. All advise is welcome as the Yamaha is new to me. Thanks...Doug

I tried the jetting forum without any luck.

Doug I would pm Dean at R&D for advice and test results.

My thoughts on this is that the 07 is lean off the pilot and the mj and needs to be 1 step richer,but the R&D may need special jetting

You might consider sending your carb for mods to Zip Ty Racing. I hear they run the Powerbowl on their race bikes now, and should be very familiar with the jetting needed. They also do some other tweaks to the carb, including a new billet AP setup. My carb is there right now!

I'd like to know if it works as advertised.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now