Can someone give some suggestions of what might be causing a plug to foul on my 1999 Sportsman 335. It came on suddenly. The motor seems to run fine until it fouls the plug. This happens after about 5 minutes of running on a clean plug.

 

Tell us more!Is the pkug oil fouled or gas fouled?Oil it will be black and wet gas will be black and powdery.

 

Thanks for the reply. The plug is as you say "black and powdery"

 

down on ur main jet...

 

If it just started doing it check your choke adjustment

 

OK, is the main jet the big screw at the bottom of the carb? Bought the thing used so I don't have a manual.

 

Here is a link to a parts breakdown on your carb http://www.partsland.com/index.cgi?N...335-CARBURETOR

 

yes it is... its the big one once u take off ur carb bowl at the bottom... take it off see the number that it says and get a lower number.... but make sure u dont go too low.... u might be too lean

 

I really apreciate your help. As I said I don't have a manual. Can you tell me how the choke is adjusted?
Thanks.

 

Here is the easiest and most accurate way I have found to adjust the choke. The best way to do it is to remove the carb enough where you can look in the front of it. Find the hole that coincides with the choke plunger. (usually to the left side of the bell) It is easiest to find with a flashlight and flipping the choke on and off. Now when you have the choke off, the plunger should be fully seated in the hole, half choke the plunger should take up exactly half of the hole and full choke the plunger should be completely clear of the hole. To make adjustments, you should have a jam nut that is on the choke cable at the carb. Loosen the jam nut, turn the cable in or out to get your adjustment, then tighten down the jam nut and you are done.