[maineman73]

Hey People!
How do you know if your sled is running rich? I noticed alot of oil and black crap on my plugs, I have a Yamaha XLV 540..im not sure of how to lean it out, or even if its an issue. any help would be appreciated!

 

[Blackcat]

To check if you are running rich or lean, run the sled WOT for 1/2 mile to a mile. Kill the engine stop as fast as you safely can. Pull the plugs out, also as quickly possible. They should be a tan color, some describe it as a cardboard color.

 

[maineman73]

Youll have to forgive my ignorance..what is WOT?? wide open throttle???

 

[Curt_Man]

Well Actually,

You dont really know where you are too rich?? You could be too rich at IDLE_________or 1/4-3/4 Throttle__________Or 3/4-WOT (Wide Open Throttle)

All which are different.

Coles Notes:

Idle- 1/4 throttle is controlled by Idle air screw, and Pilot Jets
1/4-3/4 controlled by needle, and needle jet
3/4-WOT: Main Jet


So you should test your jetting at all 3..........TO do this, just run your machine constant for at least 1/4-1/2 mile, then WITHOUT letting off the throttle hit the kill switch till you come to a stop and then pull the plugs and check the color, if you have a piston light check the wash of the piston as well...As stated white/grey NO GOOD< to lean, Dark Black > too rich.........Cardboard color/medium brown just right....

This is just coles notes on this topic, there are lots of articles on this subject if you do a search..

hope this helps....