I went riding yesterday and about 10 minutes after I left the house, my Wolverine started bogging down and sputtering. It would die, then I would start it and if I touched the throttle, it would die again. It would stay running a little better if the choke was out, but it still sputtered and I couldn't give it any throttle or it would die. It was also backfiring at the carb around the intake clamps when I would try to increase throttle. This just happened at once. It was running fine before this started. Any ideas before I take it to the shop???

 

My '99 Big Bear did a similar thing as you describe. The hose that goes into the airfilter box came off and tons of mud and water were in the filter. It was caked on the sponge filter, I took it off and cleaned it with my K&N stuff and put the hose back on, and it ran fine, I've got no idea how long it had been off either. But it ran good before, except for getting poor gas mileage. Since the hose and filter was been working properly, I've had no further problems. Just an idea...Good luck, Chris

 

Contaminates are plugging the carburetor and it is running too lean, if or when it runs. Disassemble and blow out the passages with compressed air. Especially the low speed jet, as the openings are very small.

The contamination most likely came from the fuel. Either dirt in the tank or gas dried in the bowl and left some residue. There isn't a filter in the gas line so I put in an in-line one. Also, I found out that the tools supplied from Yamaha don't include the allen wrench to remove the carburetor if this happens on the trail.

Dave Armbruster '97 Wolverine

 

I would bet that water is in your carb., drain it. The carb. vent pipe is under the seat just to the left of the air intake right where water can get in it when you hose off your atv. Hope this helps!!

 

I have an inline filter on it. When I take off the carb, how do I disconnect the throttle line so I can completely remove the carb? I'll take it off and clean it, but I'm thinking maybe it's bad gas. I had just filled up the day before. Thanks for the suggestions.

 

An inline filter wouldn't keep water from entering the carb. throught the vent line, just open the drain in the side of the carb.. To remove the carb. , take the plastic cover of the carb. (located on the riders left) remove the little brass insert that holds the cable in the linkage, needlenose pliers are a must for this.

 

Make sure your parking brake is not on. Yamaha has a safety feature that make Wolv. run like that when the parking brake is engaged. First time it happen to me I thought the thing was coming apart till I found the parking brake was on then it ran fine.

 

Parking brake was not on. That was the first thing I thought it might be. Is there any way that switch might get stuck on even if the brake is not engaged?

 

To remove the throttle cabe, pull the blake plastic cover off, then take the tension off the cable. Pull the brass keeper off the end of the cabe and slide the cable our. Thats it

 

I had a similar problem with my 97' Wolverine. After owning mine for a yea and a half, for some reason the bolt on the cam sprocket had backed off and was causing it to fire with the intake valve open, sometimes knocking the carb of the intake boot and eventually splitting the intake boot. Took a while to find the problem, by the time it was discovered it had sheared the pin, and busted the cam and the sprocket. Not sure why it happened, I had never even had the cover off before that time. If you haven't discovered the problem yet it might be worth checking, it'll save you from buying a new cam, sprocket, and pin. Also wondering if anyone else has seen this before???

97' Wolverine
27" bi-claw tri-claw combo
K&N filter
DG pipe
Drilled out fly weights on clutches ATV locker
Planning on going with manual clutch