I pulled the cover off to check the belt on the 03 trailbos. This was one some family friends ran out of oil. The belt is fine. It cranks over fine and almost starts but seems to stop spinning quickly when I let off the starter. SO no more tries on that. I am going to start tearing it apart in the next few days weather permitting, What should I watch for? I am thinking top end problem, valves etc, possibly cylinder. SHould I try and run a compression check or is it a waste of time considering it is coming apart anyway. Thanks any help appreciated. Tony

 

I hope to get some response from someone smarter than me on this one. This quad would not start. It sounded a little tight, I don't know how else to put it. Kind of life when you have something 180 out of time. It would try to start but would quickly quit as soon as I let off the key. No backfiring or anything like that. Today I pulled the valves off it. They are good, They will hold a liquid without seeping any. The camshaft looks good. I have not put a mic on it yet but there was good lift and no sign of wear on the lobes. The cylinder has no ridge at all and looks polished. I guess I should of done a compression check first but too late now. The oil has no metal in it. But this bike did shut down after being low on oil. Motor spins freely also. Where do i go from here. Thanks Tony

 

First thing low oil will hit will probably be the piston. All it takes is a light seizure or rings sticking to cause problems. Remove the piston and rings,check clearances if seizure marks not noticable on piston or cylinder. Be SURE to check for play on rod (up and down) should be none. Side to side play ok. You can just stick piston in cylinder(piston bottom even with cyl bottom) and use a feeler guage. If more than .003-.004 then will have to rebore. Clearance is tight on the 330 as well as the 500 engine. Specs show max piston to cyl clearance to be around .0025 then piston worn too far! Have had the same thing happen. OPT