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View Full Version : help!..engine is racing..(not idling)


PismoGuy400
10-12-2002, 07:47 PM
ok guys..im getting ready to set my 400 on fire...(not literally)

but i am getting really really pissed.

i put a 155 jet in it last night..assuming it would run ok..i didnt bother to start it, then this morning, i went to start it, it started right up.

as soon as it started i had to kill it..why?

because it was revved so high it hurt my ears..i thought it was gonna blow up.

then i put in a 146

same thing, but not quite as bad

the DYNOJET instructions say to run a 146...but it is nowhere near running properly..

what do i do?.

thanks
pismoguy
2K1 300EX
10-12-2002, 08:17 PM
Check the idle screw to see what it is set at.
Pappy
10-12-2002, 08:30 PM
sounds like your throttle cable is wacked out...check to make sure it is not bound up anywhere....ive seen that alot and is an easy fix.

also...make sure all air boot connections are tight etc.

good luck
PismoGuy400
10-12-2002, 08:37 PM
idle screw is 3 turns out

...what should i set it at?

(..after i try 400ex127's idea.)

thanks guys..
anyone else?
Pappy
10-12-2002, 08:39 PM
i set mine where she idled the best .....lol i couldnt tell ya how many turns out ....but should be 2 1/2 on teh air screw i do belive
PismoGuy400
10-12-2002, 08:44 PM
its not so easy..i would have tried that, but i cant get to it while its running..i have to undo everything and take the carb off...

any more ideas for me to try out..

ill do anything, but its gotta wait tiill tomorrow...if i start it now..my neighbors get mad and call the cops (mabey)
Pappy
10-12-2002, 08:46 PM
yeah its a real ****** to get too.....but i do belive the way high idle is from teh bound up cable. i bought a long thin flat blade screwdriver at wal mart and put a "custom bend" on it. it made adjustments a lot easier .
PismoGuy400
10-12-2002, 09:11 PM
thats a good idea...weve got a drawer full of screwdrivers..ill sacrafice one.

but..ill let you know tomorrow afternoon if it was the cable or not..

do you think i shoud change the jets again?
Pappy
10-12-2002, 09:19 PM
i would try the 155 if no 416 kit.....if so i would go up atleast another size.
Leo
10-13-2002, 06:26 AM
just changing the main jet shouldn't make the motor race that high...

pop the boot off the back and look and see if something is holding the slide / throttle blade open..

Leo
Guy400
10-13-2002, 06:30 AM
Yeah, you've either got the throttle blade hanging open for whatever reason or you've got an air leak somewhere (more than likely it's an intake boot. Do like Leo said, take the rear boot off and try and look into the carb to see if the slide is hanging way open. If it is than you've probably got a problem with the throttle cable as Kenny suggested.
DMH
10-13-2002, 06:54 AM
Check the play in your throttle. If you have alot then more than likely the slide is hung open. Pull the intake boot of and check it out. Needle may have goten caught on the adapter for the main jet somehow and holding the slide open.?.? Just a thought:confused:
AtvMxRider
10-13-2002, 03:19 PM
The same thing happened to me the throttle cable was out of whack. I just loosened the carb boots and moved it around and it fixed it.