umm, doesnt the big bear 400 share the same top end/bore as the warrior/wolverine and such? web cams lists the cams for warrior, big bear, wolverine and such, all the same came, so basically and warrior/wolverine top end part im guessing

 

I have a 2007 Big Bear 400. The performance mods to the engin will not help your top speed due to the gear ratio on these bikes. Even if you doubled your horse power, you still would not get past 52. The only way that I know to increase top speed is to change gear ratio. With the direct drive shaft, the only way I know to do that is bigger tires. With the stock rims, I could not find a tire bigger than 25" (Stock) to mount (if anybody knows of one let me know). This means that to change your gear ratio, your going to end up droping about 800 for custom rims and tires. Then you'll need the performance mods on your motor to push them. Moral of the story, you need a sport bike to go fast. This bike is ment to do work.

 

I had a Big Bear there just geared to low to go any faster then 45 mph tops. Thats why it screams in top gear and your searching for a 6th gear that is not there. My 250 Moto4 had the same top end and I used to get smoked by a 300 Kawasaki Lakota.

The motor of the BB is related to the 350 Wolverine and Warrior but the gearing is not.

The only cure I found was buying a different ATV if more top end is what you want. You can mod the motor all you want but its just going to make the motor scream more with no top end increase.

 

I agree with this post. I put a HMF Utility pipe, K&N filter with outerwear, rejet it to 125 on the main, put 6 holes in the air lid with uni-vents, and changed rims to the stock rims from a Rhino SE. These mods made my low end much improved. Enough that it is able to pull a wheelie without having to get back on the rack. It will out run a stock Bear until it tops out at about 53-55mph..then it just stays about a quad length ahead. This is a 2x4 model by the way. It will smoke a lot of utes out of the hole, and then lose on the top end. Its quick, its just not fast. These mods satisfied me for a little while, then I was looking for a sport quad.

 

Never owned 1 of these but in reading the thread.... if you get more low end power with a few mods.. Is it enough to pull taller gearing? That would get you more top speed..

 

I never though about that but larger tires should increase the Big Bears top end. Since the BB is not chain drive you can,t fool with the gearing with sprocket changes.

The BB screams so much in top gear,I think it can pull one size taller tires Ok.

 

I didnt think about it being a shaft drive..Like you say... taller tires would do the same thing(gear change).... would it make a Big Bear top heavy?..

 

Back from the dead but I had to post.

I have a guy with a 01 bear bear 400 punched out to a 725cc. WTH

 

I had a big bear 400 2002..it was to slow topped out at 35-40mph that maybe over estimating it..if someone says it goes faster..they need to read the mph on the speedometer and not the km/h

 

I have an 87 YAMAHA big bear 350 tha rev limiter screw is completely out the muffler has a big hole in it and it goes 44mph which is about 71 km/h also has a lot more torque