I bought my sons a used lt80 a couple of months ago, and everything has been good, until Saturday. We were riding at Lawrence Co. RV Park and having a good time when the little thing would not pull it self all of a sudden. It was raining and very muddy, so I thought that the mud must have gotten in some where. We loaded up and went home, where I took the air cleaner out and cleaned it. (It was dirty, but not real bad) But the air intake had some mud in the bottom. My question is, is the little slot in the bottom of the air intake all there is for letting air into the filter? Would it hurt anything to drill a hole above it? This is hard to describe, and you will probably have to have seen one to understand. There was mud blocking this little slot. Is there something else that it could have been? My last question is, this little thing seems to smoke quite a bit. Is ther anything I can do to make it not smoke as much? Thanks!!!

 

Your problem was not with the air box. What happened was in the transmission, there is a spring that controls the movement of the rear drive pulley. In most cases, the spring is too weak and it allows the belt to move into high speed mode even at low speeds. This problem appears more often on hills, in mud or when driven by a large rider.

The simple fix (without getting into the major mods) is to install a heavier spring. Don't go too heavy though because it will rob the horsepower from that little engine.

 

Maybe I should have explained a little better. It would not rev up enough to move it going up a slight grade. Once I pulled it back to the truck, I could get it to move, but it would caugh and spit and sputter, then it would backfire. The spring that was mentioned, Will that let it rev and not move? We've not had any problem with the belt slipping yet. (knock on wood) My kids love this bike because it's easier to ride than their Badger. It just seemed like it had to be either an air or fuel problem to make it spit and sputter. It almost seemed like my Wolverine when I try to ride it with the parking brake on. Thanks for all the ideas, I'll check them all out.

 

cough spit and backfire is classic signs of a fouled plug

the belt issue is where the engine appears to operate properly but it takes forever to get moving -- much like the brake is on.

 

I think the problem is a piece-o-junk stuck in one of the jets (common prob),thus not being able to rev. Air intake eh?! well if you are describing the piece that the air filter attatches to~~you can modify it to let more air into the filter side with no problems"exept" maybe more mud getting into the filter in bad conditions,,SMOKING~~well maybe a compression test is needed,possible bad rings could do the smoking AND not let it run,compression should be 125 or so. good luck [img]i/expressions/face-icon-small-smile.gif[/img]

 

Thanks for the replys. The compression seemed good when I bought it. (around 120-124) It had been rebuilt by a good engine builder just before I bought it. I also thought it might be the rings not seated yet, but we have put about 30 hours on it since we bought it. (This is the first problem we've encoutered) I also thought it might have gotten some crud in the carb, so when I cleaned the filter and all, I tried to clean the carb best I could, and drained the float bowl. It seems to run good now, I was tring to figure out why it all of a sudden it started to run poorly. I am planing on putting a new plug in it as soon as possible, but the little thing still starts good and easy. I would think if the plug was fouled, it would be hard to start. I really duno but I'm open to all suggestions.

 

If the plug has high speed glazing -- it is like a conductor away from the electrode. When your cylinder pressures go up (under load) it causes the spark to find an easier path and then the misfire. It usually will start without issue.