Category Archives: Yamaha Big Bear/Bruin/Wolverine ATV Discussion

Big Bear 400 advice

I bought a 2000 big bear over the weekend with "carburetor" issues. I got it home cleaned the carb and it runs great but it smokes(fair amount when running at high rpms). I decided a ring job was in order. I tore down the top end and the cylinder looks great(definitely a mud toy due to finding mud in places I shouldnt have), but no scarring or cracks. I mic’d the cylinder and it read 82.6 consistently. I have never rebuilt any kind of engine with out boreing and replacing the Pistons.

So my real questions is should std rings be fine with a honed cylinder or should I go up a size? And is there anything I should look for while its tore down?

Any tips or advice would be greatly appreciated!

Big Bear 400 advice

I bought a 2000 big bear over the weekend with "carburetor" issues. I got it home cleaned the carb and it runs great but it smokes(fair amount when running at high rpms). I decided a ring job was in order. I tore down the top end and the cylinder looks great(definitely a mud toy due to finding mud in places I shouldnt have), but no scarring or cracks. I mic’d the cylinder and it read 82.6 consistently. I have never rebuilt any kind of engine with out boreing and replacing the Pistons.

So my real questions is should std rings be fine with a honed cylinder or should I go up a size? And is there anything I should look for while its tore down?

Any tips or advice would be greatly appreciated!

’03 Big Bear Shaft wobble

Morning gents. I recently grabbed a bud’s Bear that he claimed had diff issues. The diff itself, despite the goop inside spins smoothly and freely. However the entire rear brake assembly is missing. I believe the part that is missing was once where a bearing was mounted on the right side to support the shaft, hence the wobble. I attached a pic to see if anyone can help. Also if anyone has a repair manual in pdf format, I would love a copy. :getrdone:

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Big Bear Floor Board Options

I’m interested in doing some mods to my 98 Big Bear 350 Special Edition once I finish my rear main seal and axle install.

I put some 26" tires on, but that’s all I’ve done. On my list is a slight lift, an LED light bar, and I’d really like to come up with something to add floor boards. What are my options?

Any of you who have switched from the factory heel guards to full boards, please chime in and post pics if you don’t mind. Thanks!

U Joint help need pls.

Hey guys, new member here. My name is Ryan and I’m from Ontario, Canada. Thanks for having me.

My machine is a 98 Big Bear 350 4×4 Special Edition. This machine is tough! Anyway, while I have the rear end apart for new bearings and an axle, I wanted to fix the leaking seal that’s filling up my driveshaft housing with engine oil. I understand it’s common for the nut just to be a bit loose, but I’ll go ahead and change the seal to be safe.

The problem I’m having is with the removal of the u joint so I can access the nut and seal. I have all the u joint clips out but not sure what to do now. Am I supposed to tap on the caps that ride in the yoke to get it loose?

Any help is appreciated!

U Joint help need pls.

Hey guys, new member here. My name is Ryan and I’m from Ontario, Canada. Thanks for having me.

My machine is a 98 Big Bear 350 4×4 Special Edition. This machine is tough! Anyway, while I have the rear end apart for new bearings and an axle, I wanted to fix the leaking seal that’s filling up my driveshaft housing with engine oil. I understand it’s common for the nut just to be a bit loose, but I’ll go ahead and change the seal to be safe.

The problem I’m having is with the removal of the u joint so I can access the nut and seal. I have all the u joint clips out but not sure what to do now. Am I supposed to tap on the caps that ride in the yoke to get it loose?

Any help is appreciated!