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Big Bear 400 Cam Bearing

5765 Views 24 Replies 4 Participants Last post by  dezz
New to the forum since I just picked up a 2000 Big Bear to use around the farm. Had some smoke once I bought it, only after it sat for a while so I tore it down to do a rebuild and replace the valve seals. Putting it back together I noticed the inner cam bearing was damaged so I ordered a new one. Found the same PN off 3 different sites but the bearing i recieved is 2MM too small. It just moves around inside the hole! Inside diameter fits the cam perfect but outside is not wide enough. Any suggestions? I plan on calling the company Tuesday but I wanted to start here. Any info is appreciated.

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Are you sure the Big Bear is a 2000? You may have a different year, and this might be your issue.
Is yours a 400 or a 350?
Are you sure the Big Bear is a 2000? You may have a different year, and this might be your issue.
Is yours a 400 or a 350?
Where can I find the vin on it to run? I don't have any paperwork with it so ill have to run the vin to check.

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It should be on the lower left frame rail, inside the left front tire. You may need to remove the skid plate and clean the area with a wire brush to find it.
It should be on the lower left frame rail, inside the left front tire. You may need to remove the skid plate and clean the area with a wire brush to find it.
No luck on finding the VIN. The frames been painted and I have no idea what happened to it previously. I sanded down where it should be but no luck! Only numbers I could find are: H310E-000997 stamped on the engine. I'm sure it's had a rough life hens why I got it so cheap....


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Your in the right area....should be just below the pull start on the frame....keep sanding the numbers are stamped into the frame and perhaps there has been multiple coats of paint over it.

Could you post a pic of the head and the valve covers....I am no expert but believe there is a difference between a 350 and 400 valve covers.....350 has one cover with 3 bolt, where as a 400 will have two with 2 bolts??
Your in the right area....should be just below the pull start on the frame....keep sanding the numbers are stamped into the frame and perhaps there has been multiple coats of paint over it.

Could you post a pic of the head and the valve covers....I am no expert but believe there is a difference between a 350 and 400 valve covers.....350 has one cover with 3 bolt, where as a 400 will have two with 2 bolts??
I'll head back out there and get more pics soon, but here's the other numbers I found. I also believe the head is off a newer 07-12 big bear. It has rollar rockers and a Web cam.


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Look at the bottom of the cylinder. It should state the engine size in CC.
The 350 engine was 348cc.
The 400 engine was 386cc.

Can you post pictures of the plastics, suspension. That can help us figure out the model year window.
Struck out again. I ordered the bearing for the 07-12 models and it's way to big. I did some searching and the big bear, grizzly 350, warrior 350, and a few others all cross, but the two PN's for each year set are still wrong for mine? What am I missing here? Is there another model of head that would fit on it that has a different bearing. Is there a way to find out exactly which head I have? Guy I got it from claims it's an 07 Big Bear head but considering he bought it from eBay, I know that's not true.

The numbers on the old bearing don't cross with anything, and I can't find any company who makes one in the measurements I need.

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Look at the bottom of the cylinder for the engine size. Does it state
348 or 386?

Post pictures of the plastics. This can help us identify the year range...even engine size.
Look at the bottom of the cylinder for the engine size. Does it state
348 or 386?

Post pictures of the plastics. This can help us identify the year range...even engine size.
386.

And I know it's a 2000 Big Bear 400, but when the old owner did a top end rebuild he ordered a complete head with rollar rockers and HD springs off eBay, put in a Web 956 cam and bored it 1mm over and put in the new piston and rings. I verified all the parts he said he put in when I tore it apart. Everything was great going back together until this bearing got damaged. The schematics from yamaha for the too end are identical to what I have, which is why it makes no since why the new bearing doesn't fit.

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Now that has been verified, it is possible the cylinder head is an aftermarket part. Not saying it is, but that would explain your issues.
I wish the numbers casted into the head were of value to us, but unfortunately they are not.

I am going to do a little digging into the parts diagrams and see if I can come up with something.
Now that has been verified, it is possible the cylinder head is an aftermarket part. Not saying it is, but that would explain your issues.
I wish the numbers casted into the head were of value to us, but unfortunately they are not.

I am going to do a little digging into the parts a d diagrams and see if I can come up with something.
Thanks dezz. I think it is as well, which is why neither of the PN's work. Or it's off something I havnt looked up.

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I just went through all the parts diagrams for the Big Bear 350 (single and dual range models, Big Bear 400, Wolverine 350, 1993-1999 Kodiak 400 (single and dual range models), and Warrior 350.

Only 2 part numbers for that bearing comes up.

93306-00515-00
93306-00519-00

That's it. Since you have tried both of these bearings, it will be very difficult to figure out what you got for a cylinder head.
It might just be best to purchase another used OEM cylinder head. There is lots of them on eBay.

What is the number on the side of the old bearing you removed? I can use that information to find a bearing for you
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Just went through the parts diagrams for the Raptor 350, Grizzly 350, Grizzly 400, Grizzly 450, Wolverine 450.

They all use the same 2 part numbers listed above for Camshaft bearings.

With this information, I suspect you got an aftermarket cylinder head on your Big Bear. There is no other explanation for it.
I just went through all the parts diagrams for the Big Bear 350 (single and dual range models, Big Bear 400, Wolverine 350, 1993-1999 Kodiak 400 (single and dual range models), and Warrior 350.

Only 2 part numbers for that bearing comes up.

93306-00515-00
93306-00519-00

That's it. Since you have tried both of these bearings, it will be very difficult to figure out what you got for a cylinder head.
It might just be best to purchase another used OEM cylinder head. There is lots of them on eBay.

What is the number on the side of the old bearing you removed? I can use that information to find a bearing for you
I wonder if we are looking at the same diagrams. The two parts I've tried are:

93315-32516- up to 2007
93306-00438 - 2007 and newer

Only numbers off the old bearing are NK253412 which measures 34mm OD x 25mm ID x 12mm width.

I've added some more pics for reverence. The first bearing in the pic of three is PN00438, second is PN32516, and the third is the damaged one I pulled out.


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This is what im seeing.


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LOL...oops.
I thought you wanted item #8. Not the front bearing.

I'll take another dig into parts diagrams and post back what I figure out.
LOL...oops.
I thought you wanted item #8. Not the front bearing.

I'll take another dig into parts diagrams and post back what I figure out.
Yea, it's the one inside the head, behind the rockers that the cam slides into.

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Thats the first I've seen of roller rockers for those bikes. I did a little searching for you and you may want to check into the the 350 Bruin camshaft and the newer 350 Raptor. There are some differences on those cams and bearings than the other. The 350 Bruin being what yours may possibly be. The Raptor bearing may be an update for both but from everything you've tried that looks like the more possible issue.
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