YZ400F idleing problem need help today

Ant 921

Member
Mar 11, 2007
7
0
I am posting this for my friend, he is having a problem on his yz400F. He was messing around with the idle and now it wont start. He has a manual but it dosen't mention anything about the idle. How does he put it back to stock? He tried turning it up and then turning it down to try and see if it would work and it dosen't. The bike will start and run for about 5 seconds and then just die. He check the spark plug, changed the oil, and cleaned the air filter. The problem started after he messed with the idle.

What is the stock idle?
 

Ol'89r

LIFETIME SPONSOR
Jan 27, 2000
6,961
45
Ant 921 said:
The problem started after he messed with the idle.
What is the stock idle?

Are you sure he messed with the idle screw and not the fuel screw. The idle screw should not make it hard to start unless it is turned up too far. Back the idle screw off and adjust the fuel screw to about 1 3/4 turns out from the seated position.

If the bike starts but won't idle, you most likely have a plugged pilot jet. Remove the float bowl from the carb and clean out all the jets. Make sure you can see daylight through the center of the idle/pilot jet. It is the small jet next to the main jet.

If your friend does not have a service manual, you should suggest he get one. Makes things a lot easier. :cool:

Ol'89r
 
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