Possible 4 wheeler purchase that needs work question

[Aces11]

I found a Polaris 700 sportsman for sale. Ad says it’s in great condition and ran great until now. It was run at high rpm in high gear and won’t stay running now. Any thoughts what the problem could possibly be? Ad says they believe it overheated and my need top end work. I’d be up for fixing it myself if possible. I am pretty handy as in I can YouTube something and following directions to fix it, but far from a certified mechanic.

 

[wyoguy]

You could go look at it and take a compression tester, that should be able to tell you if it's motor related. If it's hard to start generally you are low on compression. See if it runs poorly cold and warm. I've done a few 2-stroke top ends but have never done a 4-stroke, they've got a little bit more to them. YouTube can definitely help. I had a goofy fuel related thing go on with my Polaris 500 I would start with a compression check.

 

[HairyScandinavian]

Usually the seller knows what's wrong with it and decided it's not worth repairing. "May need too end work" means it needs to end work for sure. As stated above compression check and if you have a bore scope are both useful.

 

[SwampDonkey55]

Rebuilding 4-stroke small engines get can pricey quick, that’s why you’ll see tons of blown up or “about to blow” atvs for sale on marketplace. It’s usually more cost effective to find a used running engine and just swap. But that’s if you know your used engine is good as well, lot of shady people out there on marketplace lol

 

[TaperPin]

It could be an easy fix or the engine might be toast. A lot of these are out there so good used parts seem to be reasonably priced. You might get lucky and all that’s wrong is a valve hanging open, or it’s not staying running because of a fuel issue not related to the top end, but the cylinder is likely to be scored up if it was run out of oil or overheated and would need to be replaced. Running lean might have been the reason it overheated. Lack of oil might have trashed it from head to toe. It would be a fun project to get your hands dirty if the price is right.