97 Wolverine High RPM Power Loss!!

[Wolvy97]

Help! My 1997 all of a sudden has no top end power. It starts and idles just fine. The way the choke operates seems to be normal. It runs fine at lower RPM just cruising but when I need it to climb, or to get into the high end power band to go fast (open it up), it won't. It will rev up in neutral but will not under load. I havn't changed altitude conditions. I took it to my local Yamaha dealer and they said that there is nothing wrong with it.

Here's what I've done so far:

Pulled and cleaned the carb.
Rebuilt the carb. I didn't repalce the main jet, it looked okay. The floats looked okay but I'm not sure if they're adjusted properly.

Checked carb & cable for throttle action - it's okay and has full stroke
Cleaned the air filter
Changed the motor oil (but I don't think it's clutch related)
Had the valves adjusted
Checked the exhaust for fouling or restrictions - none
Changed the spark plug, properly gapped
Adjusted the clutch as per Yamaha's instruction
Checked for brake drag - none

I think that's it. Besides a general plea for help, I do have one question about the carb; is the clip on the needle jet always position in the top groove? I think that's how it was when I pulled it apart the first time and it's how I reassembled it.

Any tips or solutions will be greatly appreciated!

Don

 

[95Wolverine]

Sounds like the parking brake is active (stuck switch or shorted wiring) and is thus, activatin the rev limiter. If memory serves me correctly, the machine knows it's in neutral and will disable the rev limiter.

Does your machine have brake lights? If so, see if you can get the brake light to go on. If not, it's likely already on due to a stuck switch (foot pedal or left hand brake).

If it's not equipped with brake lights, it's possible it's the parking brake switch which is also located up in the left hand brake.

 

[joea]

wow thats the same problem i have on my 99 and ive yet to find a solution, i believe my problem is that i dont know how to properly tune my carb. i recently put a k&n, jet kit, and a snorkel, thats when the problem occured and it is driving me nuts. Please if anyone has a solution or can help out a little i would much appreciate it.

 

[Frostbite]

I still suffer with the same problem on my 06 Wolverine 450. I have tried everything like you as well with no fix.

The funny thing is, I have the same problem on my TTR225 and can't get a handle on it either.

I'm thinking it's go to be the rev limiter issue.

It seemed to help when i took off my belt and cleaned it and the clutch sheaves. It seemed grease from the clutches was on the sheaves and allowing the belt to slip and hit thus the engine was hitting the revlimiter (I think).

It also feels like it could be the carb float bowl is running dry? Because it accelerates great out of the hole but after 20 or so seconds starts to miss and pop. If I drop back to a slow speed it's good for another short burst to WOT. I raised the fuel level in the float bowl to see if it helped and it didn't seem to.

I bumped up my main jets a bunch of sizes, raised the needle with thin plastic washers to increase the fuel flow in the midrange, bumped up the size of the pilot jet too (improved starting), I tried a K&N filter as well as the stocker, I added a slidable door to the airbox lid and tried it in every conceivable position without sucess.

I need a tachometer to see how high the revs are going.

Please let us know if you figure out a fix.

Frosty

 

[c4wheeler]

carb problem maybe

i thought mine was just getting tired so i rebuilt it and still ran the same. took the carb all the way apart and found that the diaphram for the slide had a hole in it and would not lift the slide and higher rpms. idles fine

 

[2000wolvy]

be sure to check the clamps on the carb to make sure they are making a tight seal. I had a problem like that a good while back and found that at high rpms the clamp would allow a tap of air to bypass and cause a lean condition and loss of power, but under idle there wasnt enough vaccum to cause a leak. Hope thats makes since