06 yz450f jetting probs?

[saccityfire]

The bike starts and runs well with choke on, push in choke and it dies immediately. Try starting without choke on and it spits and backfires without starting. Start with choke rev and then turn off choke it misses baddly. Any help. Thanks in advance! Scot

[RCH_VisualMedia]

Its running way too lean. Adjust i would suggest turning out your fuel screw half a turn and if that doesnt fix it, go up on the pilot jet. Once it runs off idle, check it out and you may need to raise the needle one click and go up on the main. What elevation are you at?

[Wayward Son]

The bike starts and runs well with choke on, push in choke and it dies immediately. Try starting without choke on and it spits and backfires without starting. Start with choke rev and then turn off choke it misses baddly. Any help. Thanks in advance! Scot

the stock 42 pilot jet is much to lean on the 06.

go with a 48 pilot jet,170 main jet with 1.5 turns on the fuel screw.

[Ga426owner]

the stock 42 pilot jet is much to lean on the 06.

go with a 48 pilot jet,170 main jet with 1.5 turns on the fuel screw.

Burned up to what altitude for this recommendation on the 06? I am in Ga 900-1800 above sea level

Also what if running U4 (not mixed) same or ?

I will be experimenting this weekend - thanks

[Wayward Son]

sea level or so.

you should be able to stick with the stock 168 main with U4 or a 165 with regular fuel.

[batoutahell]

I am going to hijack for a second if you dont mind.

I am at about 6000 ft and ride usually from 5000-7000 ft. I have an 06 yz450 as well. Anyway, I am thinking that I should run this:

48 pilot

1.5 turns out on the fuel screw

160 main

and not sure on the needle setting.

Am I in the ballpark or is this way off?

Right now the machine runs pretty well, but it is cold as heck and I have not had much seat time. It takes alot to get it started at the moment, probably due to the stock jetting.

Thanks

[Wayward Son]

you are right on.

[batoutahell]

Thanks burned, should I leave the needle in the stock position to start out or what is your suggestion on that?

Thanks again

[Wayward Son]

stock position.

[CROGGR]

The bike starts and runs well with choke on, push in choke and it dies immediately. Try starting without choke on and it spits and backfires without starting. Start with choke rev and then turn off choke it misses baddly. Any help. Thanks in advance! Scot

You need to replace the rubber gasket on the vaccum plate on the carb slide. This just happened to a friends 06 YZ450 that he just bought. The dealer couldn't figure it out. After a few hours of testing and carb swapping......we figured it out! ? Bike runs great now. While we were in there we replaced the 42 pilot with a 48 (as per Burned) the bike runs fantastic. Now, if we could just get the bike to turn and track like the CRF and KXF does in loose conditions! Still working on that one!

[brian389]

Go with Dunlop 756, slide forks up 1/4" from top, sag at 98mm or less, and at 170 lbs, I'm 4 clicks softer on fork compression, and 2 clicks off rebound fork and shock. Taller bars a must. Fork is so smooth, you don't realize you're not far enough into the stroke. Fastway pegs in low-boy positon loads front end and helps also. Won't change mid-turn direction or dive to inside like a honda, but back into turns and lean bike further over-will track like its on rails. Lap times improved 5 seconds vs. my '04, and much better suspension/tracking than new honda, compared back to back. Honda owner was depressed after riding mine. I'm 6'1 with long arms, so may go with tall seat and Topar tripple clamps from my '04 that push handebars forward 3/4 inch. Bike balance into turns is amazing. Very easy to drift into turns standing, plant butt at apex, and rip out. About 20-25 laps total on the bike, and it's very close to "fully dialed".

Be patient and watch your lap times drop.