Helix help

[verticallydefiant]

I need some help with choosing a helix.. A ride a 2008 Polaris FST Switchback as a mountain sled. 153"X2 1/4" track. It will achieve it's desired RPM however, while climbing or crossing deep snow in a meadow it will start to drop RPM's from 8000-8100 down to 7600-7800?

The secondary is the Team one and the helix is a 64/38.65
I have looked online at the stock helixes for the 600, 700 and 800 RMK, it seems they are all running 56/42/36 helixes.. What do you think i should try?

There is also one late model build special edition 700RMK that runs a 66/44/46??

Any help would be appreciated, Thanks

 

[Scott]

Generally when you are loading the engine with deep snow or a climb and it won't hold R's then you have too much helix or not enough spring.

 

[winter brew]

I would go with a 58/40.46-58/38.46 w/red/black spring....then play with primary weight for RPM. Assuming stock primary spring?

 

[Icedog]

If it seems to be backshifting alright I'd just try a couple of grams less weight and see how it reacts to that.

 

[Himark]

I was thinking the same thing. I would drop a little primary weight first.

 

[verticallydefiant]

Thanks, I have already dropped the weight in the arms in 1/2 gram increments from 1/2 all the way to 5 grams off, all that does is make it over rev until it starts losing rpm again???? I put the stock weights back in.. It's running all stock weights, gears and springs, it just doesn't seem to want to backshift....

 

[slash]

Stock gearing for the FST is not intended for a 154 x2.24 track start by gearing down ,then try stiffer spring in your secondary.