I'm hoping someone can give me some help with this one. I just replaced the crank seal and gear case seal on my 1997 trail boss 250. Before I did this it was running great and riding fine, but i noticed gear old coming out of the clutch cover. When I took off the cover, there was a lot of gear oil in there. I took both clutches off, cleaned them with brakekleen, replaced the seal and put a new belt on. I took off the flywheel and stater and replaced the crank seal. I also replaced the starter because it was full of the gas/oil mix and wasn't working anymore. Put it all back together and it fired right up. Seems to run perfect at idle and it moves at low speed around my yard, but when I hit the throttle the engine seems to rev up normally but the quad doesn't move any faster than maybe 5-10 miles an hour. Everyone is telling me it's a carburetor issue, but wouldn't it bog down or pop or backfire if that was the case? The engine sounds normal when I rev it up, but the quad just doesn't seem to want to go. Thanks for your help.

 

Think you need to check out the clutches again. If the engine is revving up but not moving fast,then probably a belt or clutch problem. Could be the belt itself,rear clutch ramp buttons. If the belt was saturated with oil it could just need to be replaced.

 

I put a brand new belt on it. What should I look for when checking out the clutch?

 

If you still have the cover off crank it up in neutral and give it throttle. The front clutch should collapse inward raising the belt height,the rear clutch should open up dropping the belt height.Ramp buttons in the rear clutch and guide buttons in the front clutch were the main wear items,plus could be a broken spring in the rear clutch if it's not operating properly?

 

Better look something like this.

 

Thanks for the video TLC. I checked mine out and the drive clutch goes in when I rev it and the rear clutch moves out like it should, but the belt doesn't raise nearly as high on the drive clutch as yours does. It goes up some, but not the whole way. Also, the atv in general just doesn't run as well as it did before I replaced the seals. It starts great, but idles a little irratic. Everyone I talk to is telling me it's probably a carb issue. I thought maybe a timing issue since I had the stater off. I rechecked the timing yesterday and it's good. So maybe the carb is the next step. I took the plug out and it looked fouled.

 

Try a new carb kit and see if it solves the problem.89 93 250 Trail Boss 2x4 4x4 Carburetor Carb Kit | eBay