Yamaha Grizzly ATV Forum banner

02 660 not accelerating over 30mph

625 Views 21 Replies 6 Participants Last post by  Jakewells92
Hello all,
I’ve got an 02 grizzly 660, it runs great (below 30mph) idles great hot or cold. Races right up to 30mph and then it will start cutting out. Intermittently maybe 25% of the time it’ll run right up to 45 and I’d assume more but that’s all I’ve gotten it up too. The carb was recently rebuilt, along with a valve adjustment. I’m wondering if it’s not getting enough fuel or if I got a clutch issue. Any help would be greatly appreciated! Thanks!
1 - 20 of 22 Posts
What has changed is the rebuilt carb, that is where I would start. You can always check the belt for slippage and rather easy to replace.
In neutral it will rev up and bounce off the limiter. So perhaps it could be a belt. Easy enough to rule out
It be certainly worth servicing your cvt system.

I rode with a guy with a 2001 400 kodiak that woudn't go over 30 mph. Turns out the grease in the primary sheave had turned to tar and the weights could no longer move up their channels .

I took it apart , cleaned and regrease the primary sheave and it ran like a champ after that. Top off at 55 mph
  • Like
Reactions: 1
Ok, I’ve never had a primary apart before any tips/ anything I should look out for?
Ok, I’ve never had a primary apart before any tips/ anything I should look out for?
For starters don't use an impact wrench on the primary nut!
There are hundreds of thread here on G.C. about c.v.t. service/mods with videos.
Start with removing the cover and then count the ratio.
I use a wood vise to hold the primary sheave when removing the shaft nut.
Let us know what you find as you go long.
  • Like
Reactions: 1
will be working on it today thank you all for the responses. Will update
and i was just think.are u sure u are in high?cause i think in low it limit's u to that speed.
Interesting thought. According to my display it reads I am in high. My shifter cable needs to be adjusted/replaced because it’s rare I can even get it to go into L
The 660 doesn't use a shifter cable.
Hello all,
I’ve got an 02 grizzly 660, it runs great (below 30mph) idles great hot or cold. Races right up to 30mph and then it will start cutting out. Intermittently maybe 25% of the time it’ll run right up to 45 and I’d assume more but that’s all I’ve gotten it up too. The carb was recently rebuilt, along with a valve adjustment. I’m wondering if it’s not getting enough fuel or if I got a clutch issue. Any help would be greatly appreciated! Thanks!
Have you noticed the if the reverse light is coming on when the speed tops out?

X2... clean and service the primary. The grease can turn to asphalt limiting the top speed.
Well I got the primary apart not much for grease in there. Someone previously described it as tar and that’s what I’d call it too. cleaned it all up and greased it up. It’s all back together hopefully can get out to the trails this afternoon and test it out. Also have not noticed a blinking reverse light but if the problem persist I will look for that
that would not help lol. cause the weights need to move and if its like tar well then. but u should be able to notice the difference even in the yard.
Well I got the primary apart not much for grease in there. Someone previously described it as tar and that’s what I’d call it too. cleaned it all up and greased it up. It’s all back together hopefully can get out to the trails this afternoon and test it out. Also have not noticed a blinking reverse light but if the problem persist I will look for that
Once the entire job is done the belt must be all the way up the secondary sheave. Very important!
Automotive tire Rim Wood Automotive wheel system Gas

I added a picture of the inside of the primary, also I believe the belt is back in the correct position but if you could elaborate on that I’d appreciate it
Thank to everyone for contributing
See less See more
well i can say u need about a teaspoon worth of greese on each weight.then greese the rest as well. the 501 website should have step by step for u.
Put the bike in neutral and hand rotate the sheave t'ill the belt climbs all the way up the secondary like in the pictures. The sheaves will only spin in one direction.

Wheel Automotive tire Tire Motor vehicle Locking hubs
See less See more
1 - 20 of 22 Posts
Top