Just bought this today for 375, Not sure if I got a deal or not, Body is sound, and everything else is good as far as I know, but I have done some digging, owner said it had 95PSI and would need a ring job But... I tested the compression and its around 65PSI cranking with the eletric start,Now onto the questions,

I have gotten it running, and it seems to run good "once" its running, Could this still be rings? There does not seem to be alot of pressure out the exhaust like a 4 stroke (I have no experiance with 2strokes). Any ideas? I have to pour gas down the carb and that does not always work either to get it running, but once it runs its fine as long as I do not shut it off. Also it revs up on its own when sitting idleing, Almost like close to WOT, only way to bring it back down is with the brake. then it goes up again.

There is a wire melted in the harness, Its a brown wire leading into a splice with another brown wire. Any ideas? Looks factory

Anything I should also check on this machine? Are they bad for anything? Its a 86 2X4

 

Welcome! 65 psi is your main problem and don't just do a "ring job"! You have to remove the cylinder and check as to what oversize piston and rings are needed and have the cylinder bored.The revving up and down could be from worn piston and rings OR possibly the crank seals are leaking too that could be the cause of some of the compression loss! Seals are behind the front drive clutch and the stator plate. You can replace them first and see if it runs . Brown wires are ground wires and probably had some wiring issues in the past that could have done this.Plus on an engine this old you could just try to patch up what's needed,BUT If you have any slack in the rod or crank bearings,then you could end up spending more money if they fail. Best to rebuild an old motor if you plan to keep it. OPT

 

Is it hard to change the crank seals?

 

Will the cyl need to be bored? Or you figure i could maybe get away with honing?

 

You have to have a clutch puller(about 30 bucks) and a decent steering wheel puller to pull the flywheel to replace the seals. OPT

 

Only if the cylinder is worn down close to the oversize needed! Not likely though as most cylinders will be egg shaped and need to be cleaned up and bored,then final honed to proper clearance. You can spend a lot more than you initial $375 if major work is need on the engine,other areas of the atv,etc.. These old ones can be money pits! OPT

 

Ok, But the thing that is bugging me, If it needs rings so badly then why does it seem to have so much power? WOT in gear pushes me way back on the seat.

 

I should also note, When cranking if I put my hand over the mouth of the carb i can feel it sucking in.

 

Once you get it started,the rings may seal up the cylinder good enough to run for awhile,the seals may not be leaking as bad,etc. The main thing is that 65 psi compression isn't good at all. A new top end should have around 135-145 psi compression with everything right and anything below 100 psi needs to be checked into. OPT

 

It can be sucking in,BUT could be loosing bottom end compression through the seals. The air/fuel/oil/ mixture must be able to compress and shoot up the transfer ports of the cylinder into the combustion chamber to run right. You have to have good top and bottom compression on a 2 stroke engine.. 65 pounds compression is telling you somethings wrong somewhere! OPT