Hey everybody,

About my machine: I've got a 2009 Yamaha Wolverine 450 ATV. Everything on the quad is stock, nothing has been tampered with or modified.

The problem: I thought I was losing my mind the past few times I have ridden this thing. I would be doing about 20mph or so on a trail, and I could have sworn it felt like it was bogging down when I gave it gas to speed up.

It happened again the next time I took it out, and more noticeably. I stopped and shut it off for about 20 minutes. When I started it back up, it didn't SEEM like it was doing it again. However, a few minutes into the ride back home, it was bogging much more.

Now, I can't even ride it. When I start it up, it sounds fine. Listening to it idle, or driving it at a very slow backyard speed, I'd never know there's a problem. Once I nail the throttle to start going fast, it bogs down terribly, but never shuts off.

The best way I can try to describe how it bogs down is that it sounds like like there's a computer limiter that just won't let it rev up to a certain RPM.

Speculation: My impression is that it may be something computer related of some sort. Not something mechanical with the engine itself.

Can anyone point me in the right direction as to what parts I should check out or what I should look for?

Any help is much appreciated, thanks so much!

you most likely have some thing in your carb. that blocks the flow .
take the bottom off of the carburator and clean it out

awesome! thank you for the response! i just really wasn't sure where to begin. now i have a starting point! i'll get to it, and post back here with the result!

Check the vent tubes for tank and carb for obstructions, too.

I know the older Wolverines and Warriors had a problem with the parking brake switch going bad, it would keep the rpms from building so you didnt burn up the rear rotor driving with the parking brake on, my 95 Wolv did not have this, and burnt up a caliper and warped a rotor doing it !!. Check by the brake lever on the left side, see if there are 2 small wires coming from brake handle assembly. Follow them down, see if you find a plug, if so, unplug it and see if it runs any better. Im not sure if the wires need to be shorted or open to keep the reve limiter from kicking in, been years since I read up on this problem. But the primary symptom of bad parking brake switch was good idle, then falling flat on its face when you try to rev it up and move.

thanks 2wolvies! you were absolutely right. I opened up the carb with someone who knows what they're doing, and there was a small piece of some type of debris or dirt. cleaned it out with carb cleaner, re-assembled everything and it runs fine now.

thanks again everyone!