My sons friend challenged him to a best of 5 race up comp hill at Dumont Dunes.
My son on his jetted/piped/paddled YFZ 450, his friend on a very built Honda 400ex.

They've been talking this race up for over a month.

I forgot to put the card back in the camera, so you'll just have to live with my story.

I jetted my sons YFZ450 with 45P/165M/3rd clip yz needle/2 turns as per instructions on daddogs dirt riders page (lid off for the race).

The Challengers 400ex was a fast quad, but he got beat by my son on his YFZ 450 by over 10 quad lengths- 5 times.

Then the challengers dad raced us with a increased bore/jetted piped Banshee and the dad got beat by about 3 lengths each race.

All friendly, all in fun, we all had a blast.

I re jetted both mine and my sons YFZ's after several in this forum stated that how they run in your driveway vs how they run on the dunes are 2 different stories.

If ya have to be the fastest, then I suggest going to bigger jets; 48 pilot 168/170 or bigger mains, apropriate clip setting and airmix.

But if ya want a jet and forget, no hesitation on hole shot, I-don't-have-to-be-the-fastest, but still incredably fast YFZ 450 owner, then the 45/165/yz needle/Yoshi pipe is the formula I suggest.

We were at Dumont Dunes for the past 7 days and our YFZ 450's started up on 37 deg F mornings with no choke, no problem, first touch on the starter button.

The Yoshi pipe performed best with the med sound silencer installed. 96 decibles.

Chuy: From what you've said, the quad should be running like a raped ape. I did notice you said you can start the bike cold without the choke and it runs fine. The choke on the YZF is basically an enrichening circuit. It richens up the pilot jet mix. If you can start the bike without the choke, that tells me your pilot jet is one or two sizes too large. I know you are very happy with how the bike runs now and it won't hurt to keep the jetting that way. You may be able to pick up some low end response and power off idle by switching to a smaller pilot though. Just thought I'd throw that out. It sounds like the bike is very fast. Makin me proud to be a Yamaha guy.

I raced a 450 yammy this weekend at the drags with some 100 pound girl riding it. She got a better start than me and I still was tied at the end of the drags...... yamaha......pffft

Fireball right. Also, you might want to do the cam mod, basically turing the cam timing forward one tooth, which makes it the same timing as the YZ motor. Free power that you can definently feel! Youd probably take the banshee then...

RoostKing...

Lol

doh! I think I just did.......