Stock 2013 163 Pro losing Rpm

[Ken Climb]

My last couple rides my rpm's have been dropping when under heavy load climbing. They go down to as low as 7,600. On the trail or slight grade its at 8,150. I have good venting
My sled never used to pull below 8,000 ever. I now have 660 miles.
This seemed to happen after I towed my buds sled out of the bush a long way.
No broken primary spring.
I've been rotating between two belts, both of which have had some chord pull out of them that i've trimmed.

Idea's before I rip into it?
Thanks!
PS: I don't think I've ever had as much fun bushwacking on a sled before. I absolutely love this thing.

 

[mtncat1]

i'd advise you to check your clutch weight bushings,my friend was having the same problem at about the same mileage rebushed the weights and his rpm came back up.

 

[ak]

How's your belt deflection? With the used belt and the belt sitting to low in the secondary you can loose a couple hundred rpms. Also polaris springs sack out to quick it may be time for some new ones.

 

[goforbroke]

weights, rollers or springs. something is hanging up.

 

[rmscustom]

Try a new belt. Check motor mounts.

 

[Always war]

Towing out sleds is extremely hard on belts. The last time I towed my buddy's sled out he hooked me up with a new belt (didn't ask, he's just a good dude). I would definitely tear clutch down and make sure it checks out, but I'd lean toward the belt. Good luck.

 

[flying frenchman]

x3 on the clutch rebuild.

 

[Ken Climb]

Everything looks good in both clutch's (as far as I can see) I dont have a clutch puller or allignment tool. (yet)
The outer chord started pulling out of both of my belts quickly after some heavy loading.
Ive heard of this happening to others on here.
Has anybody found what cause's this?

 

[bigchevrolet]

New primary spring

 

[Ken Climb]

How do you tell if your primary spring is sacked. Do you measure the length?
If so what length are they suppose to be?

 

[rmscustom]

I have 2 belts that are junk that only pull about 7200 rpms after a fairly long pull. Only one of them has a cord pulled but both seem to be separating between the cord and top layer (deflection was adjusted good on both) and a new belt fixed my rpm issue both times. After looking at the sled last night it seems the rubber motor mounts are shot and the alignment is way off. I have a slp torque stop and new mounts on the way, hope that solves the problem. Also my primary spring broke last time out.