hello: I a 1998 yamaha 350 big bear, I want to buy another motor for it, can anyone tell me what year motors will fit this atv ? I know nothing prior to 98 will work but what about something newer ? will a 400cc motor fit without any mods ? or how about a web site that might be able to provide me with this information. Thank very much for any info you can provide...

 

There is no engine that will fit without any mods. Your best bet would be to sell the Big Bear and buy something bigger, or you could modify your engine to give it more power, starting with a pipe, jet kit, and aftermarket air filter. A cam would help and some port work would be great. It may be hard to find performance parts for it, though, because most people do not modify their Big Bear.

 

I think the 350 (348cc) big bear motor never changed and even the 400 (386cc) is just the 348 with a longer 71.5mm stroke vs a 65.5 mm stroke, both motors should be just a plain swap.

1999 Yamaha Big Bear 4X4 ATVs

 

thanks guys for the replys, I bought the machine as salvage, but its 100% complete, the only issue was the motor was partially disassembled but all there. it sat outside for over a year so the motor was pretty wasted. hence the reason i'm looking for a motor. not looking for performance upgrades just a running stock 4x4 motor 98 or newer that will fit. any thoughts

 

update, found a running 95 400 4x4 motor from a Kodiak. i'm a little nervous because i'm sure i read somewhere that in 98 yamaha made changes to the configuration of the stock 350 motor, (not sure what the changes were) which is why i was looking for something 98 or newer. anyone have any info on this swap ? what the chances all the electrical connections will match up, or the drive shafts...thanks in avance for any info

 

Go to a Yamaha parts site, if the frame part # is the same as your BB chances are the motor will most likely have to be mounted the same.

The Big Bear had the most major changes in 97.

 

America's Most Diverse - Yamaha Motor Corporation, USA, Home

 

came here in search of 350 big bear parts.whats wrong with your engine.thinking one of us may be able to help other.forgive me if I'm posting wrong or in wrong place.been looking three days and only place I can find used engine is ebay.there has to be somewhere else to get used engines.my idler gear at starter broke out of case.engine is cheaper then chasers and parts

 

Joe it's been 7 years since he last posted. He probably isn't around any longer or has the same machine.