I have an 05 Grizzly. Whenever I get into mud or try to climb a hill the bike seems to get bogged down.
It sputters and basically just runs bad. Anybody have this problem? Or any suggestions as to what is wrong or how I can fix this?

 

Welcome to the forums.
At what throttle setting does this happen at? If youre just riding down the trail in 2wd...does it do it then?
Are you in diff lock and low? Does pressing the over ride buttton clear it up?
You might be hitting the rev limiter, which is set lower in diff lock low.

 

No, it does it in 2wd and 4wd high!!
It seems to be better when it's in low range?

 

I think it might be something with the carb, what do you think?

 

Does it make a difference what the throttle setting is at? Does it only happen at wot or at 1/2 throttle?
How long has it been since the air filter was cleaned and reoiled?

 

what size of tire do you have on.

 

Sounds like the ole vapor lock problem to me. I have an 05 with 2000 miles in it and it has happened to me a few times. Yamaha claimed they fixed it a few years ago but they didn't they just made it a little better. Does it always do it on hills or only when you have been riding REAL slow or idling and then try to climb a hill.

Mine only does it if I have been riding real slow like when I am rock crawling or after it has been idling for a while, which allows the motor to get pretty hot, and then I try to gas it real hard and climb a hill. It will spit and sputter. It can be very frustrating. I have never had the problem when I am riding at normal to fast speeds and try to climb hills. It's only when I have been sitting or going very slow.

 

Have you done anything like messed with the carburetor jetting since you've owned it? I heard that sometimes, steam from the exhaust can get into the snorkel when going into water initially which would cause a hesitation. That wouldn't explain the bog when going up a hill though. That almost sounds like fuel tank venting to me. Is your vent tube plugged up? Does it only do it on a full tank of gas?

 

I had the same problem, with the quad. I figured out one reason why it happens. When you are going through the mud and the machine is hot it sucks in the steam created by the water burning off on the engine. I cut the side panels that cover the motor. I made three inch cuts along the plastic to let the steam escape before it can get to the intake. then i covered the holes in the plastic using a wire mesh with 1/2 inch squares just to keep junk off the motor. as for the hillclimb, i have not had the problem since i cut the plastic. Must also have something to do with the heat. Just make sure you don't wear shorts when you are riding, it throws alot of heat.

hope this helps

 

will this happen with my 2007 grizzly 450 ? cause that would suck