The high speed needle keeps turning as I rev the engine, is that the o ring going bad?

thanks

Yes, install a new one

those that run this engine in the rc8.2, Im not running a shim behind the collet. But the flywheel is very close to hitting the carb. I put a shim behind the collet but now Im having a hard time getting the spur and clutch bell to line up correct?

Don't run a shim. My flywheel is very close to carb, but it's fine. I'm talking around 1mm literally, but it won't rub. Unless your flywheel is bent it will be fine. With a stock AE clutch I usually like 2x1.0 and 1x.9 spring.

No shim behind the collet, only 1 between the inner bearing and the clutch nut and few at the end of the crankshaft.

I turned the carb a little just to make sure the flywheel will not touch the carb

thanks guys. Im really liking this engine. Its very easy to tune, and with the 2035 it sounds awesome. Perfect buggy engine IMO

Will the ST piston and sleeve work with the Vr engine?

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I run the 121 non tuned one with the black head in my rc8t ce and the flywheel comes very close to the carb. i can fit the blade of a xacto knife betwwen just barely, it does not hit though. i turned the carb slightly to give it some clearance any more and my linkages are not at good angles. why do you not run shims behind the flywheel collet.

chris.

Did you read up? The answer to the exact same question is 5 posts ago.

Tony Montana- actually yes, you can run the ST piston and sleeve in the VR, all of the parts are interchangeable, the ST just has all the upgrades in one package. The ST upgrades are

-ceramic rear bearing
-DLC coated and counterweighted crankshaft
-lightened piston
-lighter head

There is a notable power difference between them. A guy jumped into my buggy last race and broke the needle of my carb on the ST, so I just put in my VR instead of repairing it at the track. The VR ran great still nice to drive, but running back to back let me see the difference.

Brandon, are you telling that the 121VR piston and sleeve are totally identical to the 121vrst piston and sleeve?

I understand that they are very similar (ST piston lighter) and can be interchanged but I was 150% sure the porting was different

The piston is different but the sleeve is the same. The piston is lightened but interchangeable from VR to ST.

Thanks for the info Brandon

Just bought a brand new ST can't wait to get it here and break it in.! I'm coming from Werks motors and had pretty good life out of them. Hope these Reedy motors don't disappoint me..!!

im getting the 121vr-st as my next motor. dose anyone know how it runs with a jammin jp-1