I bought a 2008 Big Bear brand new from a Yamaha dealer in August of 2009(they had a few 08's left). I broke the motor in per the instructions and probably even then some(I really babied it). I changed the oil and checked valve clearance after break-in. At some point(not really sure when but pretty sure after oil was changed) I noticed when its cold outside maybe like 55 degrees or less and it has been sitting a day or 2 it will lightly smoke(blue) for about 20-30 seconds at startup. After that it is fine. It doesn't seem to do this during the summer months when its hot out. I bought a 2 year extended warranty that i have about 9 months left of. Is this something i should be worried about? My dad's big bear is a 10 years old and doesn't do this. Its probably a leaky valve stem seal(I guess someone please confirm) and i wonder if its worth getting yamaha to replace it. I'm more nervous about someone taking the head off a new engine. The bike only has 390 miles on it of which 200 were break in. Any advice? I really want this bike to last as my dad's has. Thanks in advance.

 

Probably becuase its cold up and its just the exhaust. Or it could be that your gas is bad and needs to be changed. Its probably nothing to major.

 

Its definitely not either of those. Gas is fresh and the smoke is blue not white like vapor.

 

Any more ideas? So far people have told me rings collapsing or valve stem seal. I just can't believe rings collapsing on new bike.

 

I have an 08 Big Bear 400...is this the same model as yours? Or is yours the 250? Mine has 1800 miles (not totally gentle miles...see avatar) on it and does no smoking...I was just outside within the last hour and started it (25 degrees and 10 degree wind chill)...absolutely no smoke.. I would suggest that if you have already purchased the warranty and still have time on it to take it into the dealer and have them go through it for you. For what you pay for the quad and the warranty, you should make sure it is running correctly. If your dealer is reputable, they should do this and understand why they are doing it. Good Luck and keep us posted on what is going on.
Mudslinger2

 

It's the 400. Only has 390 miles. I just use it during hunting season...prolly will only put 150 miles a year on it.

 

Cash in your warranty that is why you bought it!!! I put on a 1000 miles a summer (April 1-Dec. 1)
Mudslinger2

 

I hear ya but i'm not sure i want someone cracking open the head if it isn't absolutely necessary. Atv is too new to be smoking. Thats what i don't get.

 

Well that's why you bought the warranty isn't it? So if something goes wrong they will fix it for you

 

Try a winter grade weight oil like 5W sounds like your motor is running dry on start up because 10W to 20W needs much more warm up time to get that jello flowing than thinner winter grade oil.

Better yet get a 0W full synthetic, such as Amsoil which is still made for wet clutches as well. Helped my 350 Big Bear and 450 Foreman on those cold winters.