Drive belt tension

[outlaw707]

My '14 800 pro has ~40 miles, and i went to adjust the drive belt. The adjustment screw is backed out completely but it appears (its hard to get a true measurement without knowing how much to deflect the belt) a little slack.
The track doesn't engage until around 3000rpm, is this normal?

 

[jcrjet]

Lots of info about this already but....just enough deflection that you can pull the belt around with your hands when its not running, not so tight that the primary chirps on the belt while idling. Generally if you can just see the cogs above the edge of the secondary then you are about right. Clutch drive engagement is more about the weights and springs in the clutch, not so much about your belt deflection. Your belt deflection will change wear and heat characteristics, and more importantly which (gear) ratio you start rolling. You don't want to be starting in 2nd gear.

 

[outlaw707]

Lots of info about this already but....just enough deflection that you can pull the belt around with your hands when its not running, not so tight that the primary chirps on the belt while idling. Generally if you can just see the cogs above the edge of the secondary then you are about right. Clutch drive engagement is more about the weights and springs in the clutch, not so much about your belt deflection. Your belt deflection will change wear and heat characteristics, and more importantly which (gear) ratio you start rolling. You don't want to be starting in 2nd gear.

I havent found much info on here but here is a quote from anouther forum:

on the driven clutch just off ctr. there is a allen headed bolt. 1/8" and a lock nut 7/16 wrench needed. loose the nut,screwing in the allen bolt will open the driven clutch and increase belt deflection (loosen it) backing out the screw will decrease belt deflection (tighten it). the belt should just above the driven clutch 1/16-1/8" lift the back of the sled. when its right the track should just creep alittle maybe make a revolution then stop.once right hold the allen bolt so it doesn't move then tighen the lock nut.

hence my confusion...

 

[Danbot]

I hate when deflection is set by estimation or by eye... sometimes you gotta do what you can in the field but here's the shop manual way:

When adjusting out on the trail, you can get creative and use part of a shovel handle as a straight edge.
Be sure to use the belt instalation tool to "open" the clutch instead of the deflection adjuster... they strip quite easily.

 

[outlaw707]

Even with the adjustment set screw turned out the belt is 1/16 inch below the sheaves

 

[Danbot]

Even with the adjustment set screw turned out the belt is 1/16 inch below the sheaves

Did you spin the belt as you adjusted, so that it is now free? and not "clamped" by the driven clutch?

 

[outlaw707]

I hate when deflection is set by estimation or by eye... sometimes you gotta do what you can in the field but here's the shop manual way:

When adjusting out on the trail, you can get creative and use part of a shovel handle as a straight edge.
Be sure to use the belt instalation tool to "open" the clutch instead of the deflection adjuster... they strip quite easily.

my problem is it doesnt say how much force to put on the belt when measuring and i usually underestimate my strength. And even with the adjuster backed off the belt doesnt seem to get very tight.

 

[outlaw707]

Did you spin the belt as you adjusted, so that it is now free? and not "clamped" by the driven clutch?

yes the belt never seemed to be clamped

 

[Danbot]

my problem is it doesnt say how much force to put on the belt when measuring and i usually underestimate my strength. And even with the adjuster backed off the belt doesnt seem to get very tight.

Well, your not going to stretch the belt with hand force so it's hard to over do it. I push downward as hard as I can with my thumb while holding the end of the measuring tape.

 

[Danbot]

Assuming your using the correct belt, and it does not have a dimensional defect, it sounds like something inside your driven clutch is keeping it from closing.
What belt are you installing?
Did this belt adjust / work properly before now?

My next step would be to remove the belt and double check that the driven clutch can actually close fully, possibly disassemble it looking for problems inside (broken spring etc.)

 

[outlaw707]

Assuming your using the correct belt, and it does not have a dimensional defect, it sounds like something inside your driven clutch is keeping it from closing.
What belt are you installing?
Did this belt adjust / work properly before now?

My next step would be to remove the belt and double check that the driven clutch can actually close fully, possibly disassemble it looking for problems inside (broken spring etc.)

It is the belt that came on from the dealership, No issues and this was the first time i tried to adjust it. I notice two things, on the driven clutch the belt can wrap around the shaft while barely touching the sheaves. And the secondary clutch has play in the shaft while pushing/pulling to/from the engine.

 

[BILTIT]

Post a picture of the secondary with belt installed.

 

[Danbot]

The secondary (driven) clutch has some float built in.... meaning that it can slide in and out on the shaft a little to keep alignment.
Without being able to look at your sled in person, I'm a little limited to help you. I suggest bringing it to the dealer/ a shop, or find a mechanically inclined buddy who is familiar with Polaris clutches to look at it.

Possibly some high res pics might help someone here to diagnose, in the mean time.... This is some good reading for you:
http://www.snowest.com/forum/showthread.php?t=230564

 

[BILTIT]

Get the track off the ground and run it (spin the track). If the belt doesn't end up approx. 1/8" above the secondary outer edge after a few full turns of the track then you have a problem in the secondary.

 

[BILTIT]

Or your adjustment stop is too far in, loosen them off.

 

[outlaw707]

I ran it and the belt stayed below the edge. Are there more adjustment stops besides the one allen head set screw on the face of the secondary (driven) clutch?

 

[BILTIT]

Nope, just the one on a stock clutch.

 

[outlaw707]

Well looks like i get to head to my dealer in the AM then Im going to be livid if my sleds down for my first trip, (im supposed to leave friday night )

 

[LoudHandle]

................... And the secondary clutch has play in the shaft while pushing/pulling to/from the engine.

This is of most concern to me; The secondary should float axially but from your description it is moving radially, the distance from the drive clutch to the secondary clutch changes? If this is the case you have a bad bearing or worn out Jackshaft where the bearing rides.

If this is indeed the case your belt should be riding even higher out of the secondary clutch. So maybe I'm being too technical with your verbiage. I would be looking for a bad spring or interference in the secondary or a sticking drive clutch that does not fully disengage (but from your description of sheave clearance the drive clutch does not appear to be sticking.

 

[outlaw707]

This is of most concern to me; The secondary should float axially but from your description it is moving radially, the distance from the drive clutch to the secondary clutch changes? If this is the case you have a bad bearing or worn out Jackshaft where the bearing rides.

If this is indeed the case your belt should be riding even higher out of the secondary clutch. So maybe I'm being too technical with your verbiage. I would be looking for a bad spring or interference in the secondary or a sticking drive clutch that does not fully disengage (but from your description of sheave clearance the drive clutch does not appear to be sticking.

Sorry for the confusion, the clutch does not float radially as in out of round, it moves slightly on the shaft