Greetings-

I’ve got an odd problem with my 2007 Rancher 420 that started about a month ago.

When I start it up in gear, it bucks when I apply the throttle, almost like it is bouncing off of the rev limiter even though it is barely above idle. The engine generally dies when I do this. If I put it in neutral and goose the throttle a couple of times, then put it back in gear, it operates normally until the engine is shut off again. As soon as it is restarted, same thing.

It does this cold or hot. I disconnected the battery and let it sit for 10 minutes before reconnecting, no change. Air filter is clean. I just cleaned the idle solenoid on the throttle body, no change. I installed a new plug, no change.

Any ideas where I should look next?

100 Proof

 

This Chump is stumped Guys. I could really use some help here...

 

Very odd problem. I would change the fuel filter maybe to start with.
Have you ever adjusted the clutch?
I am kinda shooting in the dark here by giving you some suggestions.

 

Thanks Tramp-

It will run hard at full throttle all day long so I do not think it is a fuel filter issue. Clutch was adjusted about 200 miles ago and it shifts just fine.

This feels like an electronic issue with the injectors, ignition, or something like that.

BTW- I have a friend with the same quad that does exactly the same thing.

100 Proof

 

It's been a month since I posted this and it has had over 170 views. Has no one else has ever heard of a problem like this?

Someone please toss me a bone on this one...

Thanks!

100 Proof

 

Hold the up and down shift at the same time turn the key. After turning the key release the up and down shift and press it again for 2 to 3 seconds or until the N turn in a blinking - if it blinks 4 times its the tp (throttle pressure sensor). Its on the side of the carb or I don't know yours maybe fuel injected.

 

The front brake handle was "sticky". When starting up, it depressed the neutral bypass switch and never let it off. When I moved the handle manually to assure the switch was released, no surge. I've since freed up the handle and the problem is solved.

Thanks for the moral support. I hope this thread can help another rider.

100 Proof

 

Good info to know. Thanks for posting back.