yamaha big bear 350 4x4 smoking need help

pointblaynk · 10-20-2009, 02:48 PM

my big bear is smoking. a guy i know said i when it does that and i just replace the rings it will end up doing it again. he aslo told me i would need another piston and have to get it bored. would just replacing the rings and getting it honed fix the problem or what? any advise is appreciated thanks

ChevyBowtie01 · 10-20-2009, 03:37 PM

Honing and new rings is a quick fix. I would do as your friend recommended, bore and new piston, rings, etc. It will already be apart and for the extra cash $150 or less it will last longer than just new rings.

pointblaynk · 10-20-2009, 05:04 PM

where could i get another jug or whatever you wanna call it. cause its already bored over. i dont think i can bore it anymore.

ChevyBowtie01 · 10-20-2009, 07:47 PM

Cylinders can usually be bored a few times. If it's been bored to the max look on Ebay, and/or your local craigslist.

yamaha468 · 10-20-2009, 10:05 PM

If you just replace the rings and hone the cylinder it may quit smoking, for a little while. There's no telling how long it will work. If you want the long term fix, bore it, hone it and put a new piston and rings. While you have it down it would probably be worth a valve job or at least replace the valve seals.

*mywifeknowseverythin* · 10-21-2009, 07:17 AM

Moved your thread in here....Might get more Response in the proper forum

pointblaynk · 10-21-2009, 03:27 PM

around how much would it cost for a valve job and how hard is it to do all this?

yamaha468 · 10-21-2009, 03:43 PM

Around here it runs about 45 dollars. To cut the valves and the seats you have to have the correct machines. You could probably get away with just lapping the valves if your in a crunch for money, but it will require knowledge on how to properly lap valves.

*DirtDemon* · 10-22-2009, 10:40 PM

I agree with Yamaha468, it would be best to address the valves as well, since it is just as likely that worn valve guides is the problem. What year is the Big Bear? I merged your two threads since you posted the same question twice.

pointblaynk · 10-23-2009, 12:26 AM

its a 1994 yamaha big bear 350 all time 4wd. atleast the guy i got it from said he thinks its a 94. ist there a way i can find out for sure what year it is? cause i looked for a sicker on the frame but its not there.