2012 800 Pro RMK Clutching

[briand]

About 2 weeks ago I ended up buying a 12 800 Pro RMK 155 .

I had it all setup with the right weights, spring, helix combos that was recommended.

Heres the setup.

6000-8000 ft setup

Primary

68 gram MTX weights with 3 grams added to the tip.
Spring stock 145-330 black Polaris

Secondary

team tied
73-61.46 ( My favorite choice)
Black purple spring 160-240
.070 spacer between snap ring and spring cup roller.
2 Derlin washers.

Sled was running very well with this setup. Revs 7950 to 8050 with the ethanol plug and ethanol gas with oil for the first tank break-in.
Sled would start off the bottom with revs pulling 7900 till about 30 MPH then pull up to 8050 to top end .

2500 ft setup

Secondary

The same

Primary

Al i changed to get it to pull good was adding 2 grams to the mid hole and had the same revs as the 8000 ft setup 7900 at the bottom end to 8050 to the top.

I did have some trouble with reverse not working all the time so I checked out my tps setting and found it to be out. I got it reset to specs and Wow what a difference.

Now I am running non ethanol 91 octane premium with the 91 octane resister
and have about 150 miles on the sled I had to redo my weights setup on the MTX.

2500 ft setup
I now have 3 grams added to the mid hole with 4.5 grams added to the tip MTX 68 gram weights and I have about 8450 RPM at the bottom end 8400 at the top end. Pulls way harder now then before and still need to add more weight. I should have 71 Gram MTX for around home here but I ride very little here so I would like to use the 68 gram MTX if possible.

What I Don't know is what is the ideal RPM is for this sled. When I searched the forum I find it all over the place . Some say 8300, some say 8150 and a few even say 7900. Which is right? I,m Going to target for 8100-8150 RPM but if I can get a more decisive answer I will change this.

8000 ft setup

Secondary setup
same

Primary setup

Don't know yet but I think the 68 gram weight with 3 grams in mid hole and 1 to 2 grams outer hole should work here. Will try this out next weekend when we hit the mountains.

I would like to here from others that are running these weights. How do you have them setup for additional weights in the inner and outer holes for 8000 ft elev.

 

[winter brew]

I think most guys are running the older Team so there MTX weight/distribution will be different. 8000-8100 seems to work good on our '12 Pro and a little higher seems to work better than lower RPM....so you seem to be on the right path IMO.

 

[briand]

I think most guys are running the older Team so there MTX weight/distribution will be different. 8000-8100 seems to work good on our '12 Pro and a little higher seems to work better than lower RPM....so you seem to be on the right path IMO.

Thanks winter brew.

Did some more testing here and found that also, at 2500 ft, 8000 to 8100 works the best with 8150 being better then say 7900 to 7950 so you could say 8050 to be a good setting base. (Used 330ft and 660 ft MPH as baselines and a 55 year old butt dyno lol.)

In about 10 inches of fresh loose snow I had to put 5 grams in the mid hole and 5 grams in the outer hole to get a 8000 to 8100 rpm from bottom to top but mans this thing pulls hard now. Will need more weight in more setup snow.
I had to make up some 1/4" bolts to fit in the holes of the 68 gram MTX weights to get the 5 and 5 grams that i needed. I had to grind down the heads and nuts and bolt threads to get the right clearance so they would not bind in the spider but this worked.

I have read AKSNOWRIDER and others post about the 800 pros needing more heel weight and I have to agree with him here, there's a fair bit of gain here running these weights compared to the 10 series Polaris weights. Much better hole-shot and mid-range pull compared to the series 10 weights and my primary seems to run a little cooler also.

I know SLP and Polaris recommend 8150 to 8300 RPM but that's not what i found works best.
Hopes this helps