I have an 06 Grizzly 660...oversized tires, jet kit, exaust,....ect... About a year ago I could run 72mph, now i doing good to clear 60. Could this be all caused by a worn belt? I cleaned out the drive system and used fresh grease. It didn't help. I know I should measue the belt for wear, but its too cold out to work on it right now. It does have 3600+ miles on the original belt. Just wondering if anyone else has had this problem? and... Are aftermarket belts worth anything or should I buy OEM? Thanks!

 

So when did it do 72mph, cause mine would do that bone stock as soon as I put aftermarket tires on it dropped down to 60 as well. Sounds like your motor maybe a bit tired now with 4xxx miles on it.

 

It would run it last summer with everything as is now. LOL...Thats not what i wanted to hear. It isn't like its had a hard life or anything [img]i/expressions/face-icon-small-wink.gif[/img]...Ill put off the 686cc bore kit for a while longer...but yeah it's coming.

 

I would go buy a aftermarket cdi box for it, that should bring back some of the power. Check into a clutch kit as well, sounds like you need some lighter weights in the drive clutch and a stiffer driven spring. Go to EPI's website and see which one best fits what you have. You can also call them as they are really good at helping out. I know and have worked with they as the shop that I work at is in the same town as they are.

 

60 is way fast on the dirt. you shoudnt go 72 on the dirt anyway unless you like to eat dirt. lol.

 

You do not have a problem, The 660 we ride with is stock and does 70mph,larger 26" tires and a Belt with 3600 miles can,t help. Even if my belt looked good for what there worth and for the little effort it takes to change them I would want a new belt anyways.

4000 miles on the 660 motor is nothing,that motor is used in Yamahas daul purpose motorcycle where people have 30,000 miles on them.

XT 660

 

I put the miles and the speed on down the highway and gravel. I use my wheeler to check cattle on my farm 15 miles from my house. LOL...The only reason i'm concerned is a buddy of mine has a 650 brute and i used to be able to stay ahead of him. now he's ahead of me....so i'm sure you guys can understand my point!

 

Does anybody have a CDI box that they would suggest... and are they safe for the motor with the higher rpms allowed? I have a bad habit of checking the rev limiter's operation almost everytime i ride. [img]i/expressions/face-icon-small-happy.gif[/img]