502 carb running rich at high speed only

[Roy Teske]

I've got an SOS into Barrie but haven't been able to reach him yet. Someone with more carb experience than me may have the answer or ideas. My 502 idles great, intermediate power is good, but high speed is to rich. Carb has been cleaned. If I set my high speed at 1/2 turn, it runs great. To my mind ,something is leaking fuel at high speed??? But not low ?? This machine has been running well for 3 years. I've got the carb off again. Any ideas of what I should look for. And Bruce, I can't stop watching that DVD. Great job. Roy

[ljhuuki]

As all carbs are different in what they like in settings I usually start by running it to rich and closing high end jet from there. What I have seen in the past is the lever control arm to be bent "OUT" to far as it should be level with the inside body of the carb, sometimes it may need to be bent out just a hair outside the body. That is where I have found out many high end problems with all of the carbs I have rebuilt for all 6 of our Hus-ski - Diablos that we run. I hope this helps you out.

[Roy Teske]

Thanks for your info. Next time I take the carb apart I'm going to pay special attention to where that arm is set. Since I made that first post, I replaced the stator assembly to eliminate any electrical problem. I also found a coil wire which was probably arcing at the spark plug connection. After all this , no real top end.Same problem. I leaned out the high speed even further and problem solved. This carb is running well at 1/2 turn on the high speed. I just did about 50 miles on the week-end and top end was great. My problem started when I decided to check my mixture settings and then reset them to the recommended settings. Not realizing how lean I had it set originally. That old saying comes to mind, "If it ain't broke, don't fix it". I still think the high speed should't be that rich. Would that arm adjustment cause a rich condition?? I read that a leaking welsh plug will also cause this. In any case I think I'll leave it for now. Until curiosty gets the best of me again. Thanks again.

[ljhuuki]

The more the lever control arm is bent out the further the needle opens which would cause the machine to run rich. Glad you got it running good though. I usually can adjust the lever control arm on these machines without even having to take the carb off of the machine. Just take the guts off and see where it is and put the guts back on. Also make sure the carb is tight to the engine, I have had machines run like crap because of it sucking air.