jetting trouble?

[81dasher81]

i have an '04 400ex that ive recently put a 450r carb on. it is jetted 55/205. the other day i was just warming it up in my shop at idle, and it just stalled. so i started it again, but it wouldnt idle, and it would stay running but it would idle extremely high, like it was at about 1/4 throttle.. any ideas, or do i just need to rebuild the carb?

[JOHNDOE83]

Did you properly plug the hotstart?

You can use RTV or the actual hotstart pieces, I used RTV.

I also used a 50 pilot, 55 might be to rich.

High idle is a sign of being to lean or a air leak, if the idle wont adjust to a calm level, thel first suspect is the hotstart seal.

Thats where I would start looking.

How many turns out is the air/fuel screw?

[81dasher81]

i used RTV, so i will check that.. it at 2 or 2 1/2 turns out on fuel screw.. thanks alot, i will check the hot start when i get a chance. 55 is what was recomended for me, but im thinking about going to a 52 or 50.. i just wondered because it ran great the night before, just popped on decel

[Stickman400]

I've also got a 450 carb. on my 400 that's bored to a 407 with an 11:1 piston and I also use a 55 pilot. I tried the 52 but I had to pump the chit out of the throttle to get it to start even when it was 60+ outside. I put in the 55 and it starts right up with 2 pumps until it gets really cold. And I'm gunna agree with John, check for an air leak.

[JOHNDOE83]

If you use RTV you have to also seal the tiny hole inside the carb port facing the motor, its small and on the top side of the carb port under where the hotstart is.

The actual hotstart plunger has a spring and "plunger" that seals that tiny hole, Rtv has to be applied to the entire hole on the top side, then the tiny hole has to be filled to create the seal.

I would put my money on the seal not being that great.

[Stickman400]

Oh yeah, I forgot to mention that I used the hotstart parts to plug the hole then used RTV to plug the top of the hotstart nut. Idk if that's how you plugged yours or if you used only RTV, but mine doesn't leak at all.

[81dasher81]

alright thanks, thats what i did, i put the plunger back where its supposed to be (luckily i didnt throw it away) and sealed it all up with some more RTV and now it runs great, thanks alot