New exhaust for 2005 YFZ 450

[ynot]

Got a used Yoshimura exhaust system for my grandsons YFZ. The pipe suggests a 170 pilot /2.5 turns on the air screw and moving the clip on the needle to number 3 position. Any other suggestions or helpful hints for tuning it?

I would like to get it installed and running this weekend as he gets to make his first trip to Glamis and I want him to really enjoy himself.

[TheAlaskan]

That sounds about right for Dumont Terry depending on what set up he has for an airbox (lid, no lid, no box). not sure about glamis though, never been and dont know the elevation

It would be a 170 main jet though, not pilot....a 40/45 pilot should do well

I'm sure you know, but for anyone else reading;

no throttle - 1/4 throttle = pilot jet

1/4 thorttle - 3/4 throttle = needle

3/4 throttle - full throttle = main jet

[ynot]

That sounds about right for Dumont Terry depending on what set up he has for an airbox (lid, no lid, no box). not sure about glamis though, never been and dont know the elevation

It would be a 170 main jet though, not pilot....a 40/45 pilot should do well

I'm sure you know, but for anyone else reading;

no throttle - 1/4 throttle = pilot jet

1/4 thorttle - 3/4 throttle = needle

3/4 throttle - full throttle = main jet

Do you know what Yamaha uses as a stock pilot jet?

[TheAlaskan]

I believe I pulled a 35 pilot out of mine, but dont qoute me on that. As long as it doesnt "pop" on deceleration you should be good to go.

If your riding it and let completely off the throttle without pulling in the clutch letting the quad slow down under its own compression and it does "pop" or backfire, you need to go larger on your pilot.

[Foxysandchick]

I'm pretty sure we have 175 main, 45 pilot, 2-2.5 turns on the screw, and the needle in the middle.

Stick with a 45 pilot and pick up a 170, 172 mains to tune.

Stock pilot should be 42.

We have a full Yoshi, K&N filter and no lid, cam mod.

Aaron (sand700r) tuned it for us and now it runs great.

Sully's cycle shop in Henderson carries the individual jets for cheap.

Cycle Gear and Ride Now never had them in stock and tries to sell the kit, don't buy the kit.