KVF650 belt not disengaging

[jamen23]

Hi Guys,

Only new to this recreational activity.
I recently bought a 2nd hand KVF 650 2003model. It had a set of cracked cases on the reverse gear shaft. So I got some second hand cases and rebuilt the motor. The rest of the motor is sweet. Hasn't done much work by the looks of things.
I have assumed the reason for the cracked cases is because the previous owner must have thrown it into reverse or fowards(vice versa) while the motor was trying to drive the gear box.
The problem i am having is when it is idling, its all good, but as soon as i put it into either reverse or forwards, it wants to drive even at idle. I have to put the rear brake on to stop it, but then the belt screams like its slipping. I took the cover off to inspect, and started it up to check if the sheaves were grabbing the belt at idle, but they are not. I have the motor barely idling so the clutch doesn't grab.
The belt appears quite new, no wear marks anywhere. The shaft that the inside of the belt rubs on is shiny, and clean.
Just can't seem to work out why it doesn't disengage. I just don't want to destroy the engine like the last owner.

Any advice would be helpful.

Cheers

[3Wheeler]

It appears that either your engine brake actuator is NOT working (pricey) or your friction fork is worn past the service limit (pretty cheap) Listen for the sounds of the actuator working (is on the top of the belt cover) when you slow down to stop you should hear something engage. if you do hear something then more than likely your fork.

[3Wheeler]

Is it possible the idle speed is set too high?

[bbertram]

Belt might be to set really tight. Unplug the engine brake actuator on the belt housing and see if that helps. The idle speed is a good idea too.

[jamen23]

Yeah, I initially thought the idle was too high also, but when i had the cover off and the engine running, the sheaves weren't even contacting with the belt. So that will also rule out the brake actuator as well.

How do you adjust the belt tension? Do i have to put shims in the pulley on the gear box side?

[3Wheeler]

Did this just start happening out of the blue?

[timmytorco]

Do you have the right belt on the machine??????

[jamen23]

Well, this is the first time i have had the motor running since i got it after the rebuild. So i don't know what it was like before it. The belt is the correct belt for the machine. This is something i also checked.

A kinda weird & frustrating situation.

[Vertigo]

Isn't that the same motor and similar clutch set up to the Arctic Cat quad a few years back? If you are struggling for answers, maybe call Crikside and talk to one of their mechanics, I remember seeing Bob write something a while back about how they used to work on those bikes when they were out.

I could be wrong, but worth a shot?

[jamen23]

I might try a new belt and see if that remedies the problem.

[bark]

your belt is to tight, with the cover off, push down on the center of the belt and see how much it moves, I always set mine so that when holding the top and bottom together there is clearance all the way around the primary clutch shaft. There are shims in the driven clutch (tranny side) you need to add some shims to get more belt clearance.

[jamen23]

I have checked the belt deflection according to the manual. It appears to be within its limits. None the less, you may be onto something there. I will order another belt also just out of curiosity. In the meantime, i will shim the clutch on the tranny side as suggested. Hopefully this may solve the problem at hand. Will post my progress and any success or failures I encounter.

Cheers

[powerstroke]

You shuold check a manual but the secondary can be shimed to allow the belt to move out on the primary clutch . this slack will stop it from driving and squeeling.

[kawasaki dude]

my 03 650 did the same thing with an aftermarket belt from napa. i then put a kawasaki belt on and that fixed that issue. wether or not the after market was just a tad smaller i don't know, but i never had the problem again with an oem belt.i know the kawi belt went on not bad ,but the aftermarket was really tight going one. hope this helps.later have a good one.

[jamen23]

Originally Posted by powerstroke

You shuold check a manual but the secondary can be shimed to allow the belt to move out on the primary clutch . this slack will stop it from driving and squeeling.

I did as you suggested. I shimmed the pulley on the gearbox side. The belt doesn't scream anymore. I can put it into gear without it trying to drive when the motor is idling. whoo hooo....!!!!

Thanks heaps for everyone's help and suggestions.

[jamen23]

Originally Posted by bark

your belt is to tight, with the cover off, push down on the center of the belt and see how much it moves, I always set mine so that when holding the top and bottom together there is clearance all the way around the primary clutch shaft. There are shims in the driven clutch (tranny side) you need to add some shims to get more belt clearance.

I did as you also suggested. I shimmed the pulley on the tranny side. It has fixed the problem.

Thanks for your help... :-)