Belt Travel in Polaris Primary

[volcano buster]

2010 660 RMK.
SLP blue/pink spring 62.3 gram 10 series weights
Black Purple spring - 60-40/.45 helix
19:42 gearing
155 track

I marked the clutches last winter to see how far the belt traveled. It looks fine in the secondary, but the belt doesn't look like it travels very far up in the primary. Should it, and what should I be looking to change to get it there?

I usually have mixed road/tree/ditch type riding with minimal straight up chute type riding. I did get the rpm's in the 8200-8300 with a few blips to 8500 at lower elevations.

Thanks

 

[NapaMatt]

Make more Hp!

or. Down your Springs Pressure Finnish Rate

What elevation?

 

[volcano buster]

Usually 4-6K.

I'm tapped out on power. I could drop a lower spring in I guess and try it.

 

[LoudHandle]

Gear the B!tch down, 19/46 or 19/47 if I was running a chain case. Guessing stock drivers and stock track. If you ever want a Polaris Mountain sled to use all the clutch in the mountains, you will need to gear down.

 

[volcano buster]

I'm running 19:42, correct stock track and drivers.

Is there an advantage to gearing them down further just to use more of the clutch face?

 

[LoudHandle]

You are currently geared for 80 MPH at a 1:1 clutch ratio, by re-gearing it to 19/46 you are then geared for 74 MPH. There is some overdrive built into the clutches so you really don't lose any speed by gearing down, but you gain belt contact and less heat generation and slip. You make the work the clutches have to do, easier on them, that translates into; longer belt life, less heat in the belt and clutches, full shift out (using the entire clutch surface, rather than just wearing out the throat of the clutch).

I see no down side. Some may claim you lose backshift, but if you do, your not clutched correctly to start with.

 

[winter brew]

How far the belt travels is strictly related to the speed you achieve. On most stock sleds, it will only use the entire sheave on a looong, flat run where your top geared MPH is reached. And it will always be the same in primary and secondary as the belts don't measurably stretch, so marking the secondary isn't really necessary.
I have always like the P-85/team combo at a 2.15-2.25 ratio for a 155-163 track, but different clutching likes different gearing....they work in unison so experiment to find what works for you and your particular sled and riding style.

 

[volcano buster]

Thanks.

I'm geared at 2.21. We typically get wet heavy snow so I figured gearing to that point would help keep the belt happier longer. I have been fighting top end rpm with the clutching since I got it. It had an almond round primary spring with 62's. It would rev to 8700-8900 real easy while breaking the track loose. It didn't feel like it ever loaded the motor and pulled hard though. With a helix change suggested by Carl's, the lower gearing and the SLP blue/pink spring it hits the 8200-8300 rpms now, but I was curious if I shouldn't be running the belt up the sheave more.

 

[TRS]

I run the 19-46/20-46 as well. Great combo's