I have a question. I need to know what specs I need for my Raptor. I have the White Brothers full exhaust system with 12plates and a K&N filter with the air box lid removed. Any Idea? I was thinking 150/155

I run a Big Gun exhaust and at the suggestion of someone else I jetted my Raptor at 150/155 and it runs great. I don't have the K&N though. A friend of mine runs the same exhaust I do with the K&N with the air box lid removed and he runs a 160/165 so maybe that would work better for you Good luck.

Thanks... I'll just try both. See how It does. It was running fine but I have a feeling I need bigger jets. :wink:

I went up one size on the jets, a K&N and the GYT exhaust.

The power increase was phenominal.

Went from adequate power to fun power.

I'd a gone more on the jetting,, but felt one size was OK for me and any more mean't possible more fine tuning that I didn't want to hassle.
Pure lazyness on my part only, so by all means,, goose it more if it suits ya..

The Yamaha jets come on a shrink wrap card with 8 different sizes to choose from.
Part No GYT-5LP98-00

I bought my son a YFZ 450 and I can't be letting him kick my but on the dunes now can I????

160/165 should be in your range.

I had stock jetting in mine (T4 exh. UNI filter intake) and the jet-hot coated exhaust pipe was glowing red hot; in fact, it was actually translucent it was so hot. I stepped up to a 150/155 and seems to run fine and no red-hot exhaust.

Maybe I should step up again to see if I can get even MORE power?

Do a plug check at least third gear wid open hit the kill switch then pull clutch in check plug for the cinimun color. Dunes you want a little richnot much. Most four strokes produce more power leaner.

Doc

Any updates on jetting on which works best? My girlfriends bike, full fmf with power bomb header, pro design kit with no air box lid kn and outerware. Im starting with 150/155 used only at galmis and what are you setting the mixture screw at (turns wise) from full in?