Idle Increases significantly after bike warms up.

[Heritage Guy]

After the bike warms up the idle wants to increase from 1400 rpm. I keep having to adjust the idle screw but the problem persists. I did recently install a fuel filter between the tank and the carb. I will try without the filter. Any other ideas or suggestions as to a probable cause would be appreciated.

 

[16VGTIDave]

The fuel filter is fine, leave it! Your idle mixture is a bit lean. Richen it 1/4 to 1/2 turn on each screw and then fine tune and sync.

 

[Heritage Guy]

The fuel filter is fine, leave it! Your idle mixture is a bit lean. Richen it 1/4 to 1/2 turn on each screw and then fine tune and sync.

Thanks for the info.

 

[Heritage Guy]

Where are the idle mixture adjustment screws located on the carb? I read in here that they should be set at 3.5 to w.75 turns out from fully closed. Wouldthis be correct?

 

[16VGTIDave]

Top of the carb, between the diaphragm housing and the carb mount. Above and just forward of the throttle shaft. The adjustment is just a guide to get the bike running. It should be tuned for correct operation.

 

[Heritage Guy]

Thanks. Appreciate the advice.

 

[arfstrom]

http://www.xs400.com/forum/showthread.php?p=114664
This thread has some really good pics of changing you idle screw.

 

[peebuck]

witch way is ritch and lean??

 

[xschris]

Out is rich and turning the mix screws in is lean.