RPM in Deep Powder

[NoSoup4U]

Finally got a chance to ride my 14 800 in the deep powder. I was only pulling 7800 +/- 100 RPM. Is this normal? The specifics are:
14 Pro RMK with 163 track
Stock motor, pipe, can
8500-9000 ft elevation
Polaris spec clutching with 10-60 weights and purple/ black secondary and 1 dehlrin washer under the gold cup.
I weigh around 175 ready to ride.
Sled pulls 8100-8200 RPM on the hard pack.

What RPM is everyone else seeing in the deep powder at elevation? Thanks

 

[MTN Powderhound]

At 5500ft my 13 163 pulls 8100 indeep powder. All stock with a delrin washer in secondary and an slp torque arm. Stock clutching.

 

[AndrettiDog]

You should be shooting for 8250. That's the magic number. If you are only at that elevation (and not say...11k-12k) I would expect you hit 8250 at your size. Sounds like the miles are low if it's a '14 sled. I'd check some stuff like making sure the clutches are aligned and sheave clearance is good on the secondary.

I had to grind my 60 weights down to 58.5 for where I ride. but i'm 200 lbs and ride more at the 10k-12k range so you can see why I came down so much. You are losing power band if you are only getting 7800 RPM's.

 

[AndrettiDog]

Oh yeah, check to make sure you primary spring isn't broke. That was a problem back in '12 sleds. You can put the sled on it's side and pull the clutch cover off. It's worth the check.

 

[NoSoup4U]

Pulled the primary spring, and it looks good. Sled has about 140 miles on it, so maybe RPM will increase as it gets more miles.

 

[MTN Powderhound]

Mine pulled 8100 right from the new. Has 200 miles on it. Need more snow.

 

[WileyCoyote]

clutch

I don't worry about a little over rev on lower elevation trails on the way in, I clutch for a long pull at 10000' elevation for 8250' you might try 58's(that is if you like the engagement and back shift)

 

[Bossman]

RPM in deep powder

I have have had good luck with the Team 210076 Red/Black 140/240 driven spring in the Pro RMKs. Seems to reduce clutch heat a bit and improve backsift over the blk/pur spring. Check your 60 gram weights on a gram scale, as most of them are 60.5 grams or so. Grinding the sides to 59.5 grams for starters with the Red/Black spring should get you very close.
Also, if the barometric pressure was low that day, your power valves may not have been opening at 7800-7900 in the powder. SLP is atimate about using the pink PV springs in altitude applications and I use them in stock Pros down to 4000 ft.

 

[NoSoup4U]

Thanks Bossman. I thought the exhaust valve spring was only an issue on 800s prior to 2011?

 

[sledsnowco]

You need lighter exhaust valve springs and less weight in the primary, if you want it to pull 8250 at 10,000 ft you will over rev a little at the trailhead.

 

[diamonddave]

I have have had good luck with the Team 210076 Red/Black 140/240 driven spring in the Pro RMKs. Seems to reduce clutch heat a bit and improve backsift over the blk/pur spring. Check your 60 gram weights on a gram scale, as most of them are 60.5 grams or so. Grinding the sides to 59.5 grams for starters with the Red/Black spring should get you very close.
Also, if the barometric pressure was low that day, your power valves may not have been opening at 7800-7900 in the powder. SLP is atimate about using the pink PV springs in altitude applications and I use them in stock Pros down to 4000 ft.

Interesting...is this with the Stock helix? And what altitude?

 

[Bossman]

RPM in deep powder

I use the stock helix in bone stock sleds with the 140/240 spring and 62 gram weights from 6000-8000 ft and 60 gram weights from 8000-10,000 ft, pretty much the Polaris setup except the driven spring and cutting the weights to 60 .0 or 62.0 grams. I tried this setup after finding it it in one of Keith Curtis's old sleds that was in for service. It also had the pink PV springs in it.

 

[WileyCoyote]

Lighter exhaust valve spring interesting, anyone else trying this?

 

[goforbroke]

What is the stock power valve in an 800? Everything I could find shows the pink spring is stock and has the same rate as SLP.

 

[crashnbash]

A 14 pro rmk show an orange exhaust valve spring on the parts microfiche.

 

[Scott]

Finally got a chance to ride my 14 800 in the deep powder. I was only pulling 7800 +/- 100 RPM. Is this normal? The specifics are:
14 Pro RMK with 163 track
Stock motor, pipe, can
8500-9000 ft elevation
Polaris spec clutching with 10-60 weights and purple/ black secondary and 1 dehlrin washer under the gold cup.
I weigh around 175 ready to ride.
Sled pulls 8100-8200 RPM on the hard pack.

What RPM is everyone else seeing in the deep powder at elevation? Thanks

I've heard of guys running 58g weights above 8500 feet elevation.

Also, during break-in it will run a bit tight. Mine was only hitting 8000 to 8100 during break-in with STOCK FACTORY clutching out of the box at 6500-7500 feet. Once I got to 200 miles, I was hitting 8400 on the trail and 8300 on a hill.

My R's dropped a bit during the season and finished at 880mi. Fresh clutching this fall and yesterday I hit 8500 and held 8400 on the trail. Back in biz.

 

[Teth-Air]

I noticed mine doesn't rev quite as high in ethanol mode either as it has slightly less power. I did notice it stayed a bit cooler on the trail though (remember this in the Spring when it runs warm)

 

[sledsnowco]

I run 58 gram weights above 8,000 ft. If you run 60's there's no way your gonna achieve 8200 in the deep powder. All pro rmks or assaults come with orange exhaust valve springs, pink or yellow will do the trick.

 

[NoSoup4U]

Is there any downside to running the pink exhaust valve spring compared to the stock orange?