Jetting. Good place to start question.

[phatdad]

Hello. Just finished my Roberts edition restoration. My bike has the RD Y tube single air filter, Tommie exhaust, and Force V-tec reeds.
The bike is running, to me at least extremely rich. Main is a #420 and pilot #25. A heavy smoker and the plugs are very wet. Just ran it once to operating temp then shut her down.
I have some 2 stroke dirt bike tuning experience but the rz-350 is new to me. Thanks

[Darrell]

This is what Toomey recommends (and sells, of course) for his pipes. The main isn't doing anything when you're just bringing the bike up to temp, if you're running rich while idling look to the pilot circuit, and pay particular attention to your float setting.

SPECIAL NEEDLES AND MAIN JETS GROUND SPECIFICALLY FOR THE STOCK CARBS OF THE US MODEL RZ. NOMINAL SETTING IS NEEDLE ON THE THIRD GROOVE, #410 MAIN JET STD FLOAT SETTING (21MM +/- 1) STOCK #20 PILOT JET, PILOT AIR SCREW SET AT .5 TURNS OUT (1/2 TURN OUT)

[phatdad]

Thanks for the reply, Darrell. Ran the motor a little harder today, after warm-up. Sounds great, nice and crisp on the throttle response, still quite the smoker even in the higher RPMs. Will follow up on the Toomey recommendations. #230 jump to #410 just seems excessive, what do I know. Not much about tunning this motor.