Hey guys. I have a 2000 Yamaha Big Bear that is blowing white/blueish smoke and there is a small amount of a milky oil substance that comes out of the exhaust. I'm not really good with atv engines, but I'm thinking that it may need new piston rings? Can anyone point me in the right direction as to what all I should do to fix this problem?

 

If the exhaust has a "burning oil" smell, then yeah, you probably need new rings. About the only other thing it could be is valve seals but if they are worn that usually causes it to smoke worse on startup. If you do a rebuild it might not hurt to have it all replaced while you have it all apart. If the exhaust smells more like gas then there is a problem with the carb.

 

It didn't have much of a smell but I'm pretty sure it was oil. def not gas. When you say have it all replaced can you explain a little further? can I buy a rebuild kit that has everything. I've looked around a little bit and I have seen a kit with just the rings, but I want to make sure I get any gaskets and whatever else I need.

 

I had that problem on a warrior I replaced rings valve seals and top end gaskets, cost 50 dollars and doesn't smoke anymore. the gaskets and valve seals were together for 30 dollars.

 

Cool best advice I've seen. Do you know of any youtube vids or step by step guides that would help

 

not sure of any for a big bear specifically but its pretty simple the rings will come with instructions and just look up torque specs to tighten back down. the valve seals will give you more trouble but if anything it like 15 dollars for a mechanic to change them, I did it with a hammer a spark plug socket and a few wrenches. O and by the way not sure about the big bear but on my warrior it was much simpler to pull the engine and saves a lot of busted knuckles.

 

Okay. So I found a set of piston rings for the atv. But everywhere I look is just rings only. What all gaskets will I need and is there anything else I should consider while the engine is broken down? I plan to do the valve seals while the engine is out.

 

http://www.ebay.com/itm/Yamaha-Big-Bear-400-2000-2006-Top-End-Gasket-Set-Valve-Seals-/380670073451?pt=Motors_ATV_Parts_Accessories&hash=item58a1b45a6b&vxp=mtrcomplete top end kit with valve seals. and then just get the rings. also get it honed while its apart any shop can do it for around like 15 dollars.