What size jets on the pilot and main, what number click on the pin, and how many turns on the screw?

Thanks,

Chuy

Depending on your pipe, Go up 2 on the main(162) and 2 on the pilot(48). 1 3/4 turns out on the fuel screw and that should be sweet. Unless you have the Big Gun exhaust. Couldn't get it right. Now, it's Yoshimura to the rescue. Good luck. Peace

Check out YFZcentral.com
they have everything you need to know about jetting.
I have the airbox completely removed and the sparky out and I am jetted
48 pilot
175 main
4 clip on NCVQ (YZ450F) needle
2.5 turns on airscrew

All this and I think that I am still a little lean. (occasional back fire when I let off the throttle)

Late

"Chef" I think you might be a bit lean on the top there unless you have no pipe on airbox nod.

With a pipe and airlid off you should be at a 45 pilot with clip in the 4th and about a 170-175 main. This is if you have the stock needle. With a different needle you might want to step to a 48 pilot, and at around 2-2 1/2 turns out. Start at 2 1/2 then fine tune it from there. Get the Zip-ty screw from Alba it makes it alot easier. You'll run into trouble if you go below a 165 main and 45 pilot, no matter what some shop tell you ie...ALBA

Do the cam mod!! Try this web site for jetting and good maintenance videos!


http://www.eskimo.com/~daddog/

YOu should be able to buy one from the dealer. They may have to order it. I got mine from Lebard and underwood in la habra ca. If you check out the YFZcentral.com site, they have a guy... Woodward Specialist that will ship it to for for like 11-12bucks. He is a yamaha dealer somewhere (forget). The link is on the home page, it should be flashing the name.

If you dealer is trying to pull that with you, go into there and ask for a needle to replace one form your YZ450 dirt bike. Its the same needle. DOnt tell them you have the YFZ. Should work and they wont try to sell yyou the kit.

Late

MIstake, the place to get the needle is Magnolia tractor and yamaha. I think there is a link to info about the place on the YFZcentral site.

LAte

Got the backfire problem taken care of. Had an exhaust leak at the head. Everything else seemed OK. But the top end test is down the street. We'll see in G. I'll get extra jets just in case. Peace