I am looking for advice to a problem with my 1996 Sportsman 500. About 15 months ago, I had to replace a defective camshaft due to the exhaust lobe on the cam wearing completly down to nothing. I guess the first year build on these had this problem. Bike was running good after camshaft change. About 8 months ago, I had a dirty carb problem and had to remove and rebuild carb. After that everything was great. Now, the bike is running terrible all of a sudden, meaning backfiring, cannot idle, plug is all black and fouled out, no power at all. I have once again torn apart the carb and cleaned it and found nothing. I am getting fuel and good spark. My question is:

1. Could I of burned an exhuast valve from the prior camshaft incident?

2. What to check next before tearing down motor? I am going to inspect the camshaft and timing chain from the inspection plate.

Any help would be appreciated....[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

The first thing to check is to make sure your ETC is correctly adjusted. To do this, remove the throttle housing cover, if it is metal, make sure the contacts are touching with the tension of the throttle cable, if it is plastic, make sure the contacts are NOT touching with the tension of the throttle cable. Also, after you make any adjustments, turn the steering lock to lock and make sure there are no idle changes, that would indicate too tight of an adjustment. If all that is good, make sure your choke is adjusted correctly. Over time the cable will stretch and you will have to make minor adjustments to both of these areas. If it is neither one of these, I have no idea.