Hello everyone,
Great forum here with a lot of good info. I recently was given a '99 Trail Boss 325. The last owner took good care of it. The wheeler was getting harder and harder to start so he gave it up. It has 55 pounds of compression, no doubt the reaon it won't run. I can start it by choking it and letting it run at a fast idle to keep the compression up enough to runthe fuel pump. It still has decent pep even with the low compression. The seat is mint and there is no broken plastic. I took it in to a reputable atv repair shop and they told me to junk it that it wasn't worth fixing. I was planning on just putting rings in it to restore the compression. The mechanic said those 4 strokes rarely are fixed just by putting rings in. It would need to be bored and completely gone through. Not worth sticking the money into.

I guess I am looking for some second opinions. Thanks.

 

Welcome to the forums.

The fours aren't the quick and easy fix the two strokes are. Could be more than just rings causing the low compression. Only way to know for sure it to break it open.

 

Guess I should clarify that a bit. It could be an easy fix, but there's a lot more moving parts to go bad in the four stroke.

 

I agree. I have pulled apart many 2 strokes and just changed the rings with good results. I pulled the cam cover off and checked the valve clearences just to make sure one wasn't sticking open. It looks pretty hard to pull the jug off while it is in the machine. The timing chain could be a real bear.

 

Std piston to cylinder clearance is .0015-.0032 Wear limit is .004(considered worn out) Plus like Scootergptx said there are more parts that really need to be replaced such as the timing chain you mentioned, plus I wouldn't just slap the head back on with out at least lapping the valves,new valve guide seals,etc. If you could tear it apart and have a machine shop look at then you could have a better idea on cost,plus if you can do the assembly work could save some $. That is if the rod is ok and the engine doesn't have to be split and have the crank turned for oversize rod bearings. OPT