frustrated... please help

[f150mann]

im tired of it im gonna burn the 400ex to the ground!

okay i put on a hmf slip on, jetted the main to a 155, pulls good, no bog, but on decel it is backfiring.

i turned the air screw all the way in, then out 4 turns, took it for a drive.. did seem better, still backfires sometimes just doesnt seem to be as often, but it could just be in my head and still backfire as much.

then after like 1 minute of riding, it wont idle! i have to keep my revs way up or it will die. wtf is going on...

i beleeeive it was the air screw i changed? it idled good at first, it was like underneath the screw for the idle right?

[redrocker]

Try going up to 160
I run a 165 in my wifes
bike and runs great with
lid on and even better with
lid off I'm at sea level. When it back fires
when letting off it is running lean
Hope this helps

[redrocker]

P.S.
Air screw 1 3/4 out

[redrocker]

P.S. AGAIN(sorry)
check for exhaust leaks also

[f150mann]

no leaks, when the exhaust cools down im gonna put the air screw back to 2 screws out and see if it will idle then.. if it does then what? 42 pilot?

[chris46250r]

Yes on the 42 pilot.

[f150mann]

well i just hauled the carb off.. and what did i find but the screw is GONE. it fell out grrr ga no wonder it won't idle!

[chris46250r]

If you had it 4 turns out it was just hanging on by a thread.

[400exrider707]

Changing the main only helped from 3/4 to full throttle, you didn't do anything to compensate for the added flow on any of the other circtuits of course its not going to run correctly.

Do you have the lid on or off?

IF off try:

155 main, 42 pilot, move the clip on the needle to the 4th from top, and 2 1/2 turns out on the screw.

[f150mann]

for now the lid is on.


i walked two miles through my yard across a road and down a dirt road.. i found my fuel screw on the dirt road!!! wahoooo!!

and i ordered a 42 pilot jet, and put my fuel screw back in, to about 2.5 turns out.

[JOEX]

Originally posted by f150mann
for now the lid is on.


i walked two miles through my yard across a road and down a dirt road.. i found my fuel screw on the dirt road!!! wahoooo!!

and i ordered a 42 pilot jet, and put my fuel screw back in, to about 2.5 turns out.
Dang! Nice find:cool:

[f150mann]

i thought it was toast! but with the dealer wanting 25 bucks for a new screw, and taking 10 days, i had to look. glad i did!

[honda300EXtreme]

man you are sooo lucky you found that

[QuadManiac]

Hey, I lost a 20 dollar bill, somewhere between my house and the local 7-11 last week... wanna come help me find it?

[blasterandy]

ha, i remember my friends dad lost a front fender off his dbike and this was like the day after they bought the bikes. About 2 years later i went riding and found the fender laying in the middle of the trail. This is after all the clean up days and matenince things they do. Tells you how hard they try :rolleyes: