Jetting help

[EJ Racing 07]

So I got our FCR 32mm installed and I'm unfamiliar with the best way to jet a four stroke. It's a CT built motor, right now it starts and idles great, will rev up if you bring it up slow but if you punch it, it will just choke out. Where do I start and what steps do I take to get this thing screaming? Thanks for any help!

[mxdad423]

what size main jet are you running? We have a Rage built engine, we are running a 130 main, actually just jettet it down one size this past weekend, was at a 132 but with the change in weather had to go down one size. Sounds like you need to go up on your main and may also have to adust your needle.

Kevin Smitley

[EJ Racing 07]

Well I started with a 138 and have popped in every size up from there, I'm at a 150 now with the needle clip on the lowest. Nothing has changed through this process, the way it sounds I might have to start at 138 and go down that I'm way to high. If you know, there is a small screw in "jet?" if you take the bowl off of the FCR, leave that along? I was just working in adjusting the main, fine tunning it with the needle position then dailing in the pilot? Thanks

[mxdad423]

Yea you may have to go down, the four strokes can fool you sometimes, it may act like it doesn't have enough fuel where in reality you are actually over fueling it. try going to a 132 and setting you needle in the middle posistion and see if that helps it out at all.

Kevin Smitley