What is the proper clutch combo to pull max rpm?

[davermk]

my 2010 rmk 800 155 will not rev over 7600rpm. The primary weights were the 10-62's and I switched to the 10-58's.. this seemed to help. but im still not hitting 8000 rpm. Is there a secondary clutch spring that i need to be using to help the rpms come up to max power? Also any links to charts showing the correct combos of weight and spring would also be a help. I do 80% of my riding at 10,000ft +.
what do i need to do to get the sled to max rpm and hold it?

 

[Adobe-Al]

What is it hitting with 58's? what is the condition of your belt? also a buddy of mine changed plugs and gained a 200 in RPMs. Are you in the steep and deep or on the trail? snow conditions makes a big diff. is your ethanol wires pluged in or not? mine hits 8250 on the trail and 7900-8000 in the powder. I do have a PCV and 58's the PCv runs it leaner on top. What spring are you running in the primary?

 

[Himark]

We ride 9-11k all the time and I also am running 58's in a 09 it pulls 8100, my buddies 10 model pulls 8150. I would be checking your clutch to be sure it is all in order. Your sled sounds like its down on power if all others look good. You could drop a lower weight to compensate would be my suggestion.

 

[2XM3]

time for a good leakdown test, 10-58's and ur best is 7600?? you have a issue in the motor.
i'd take a good look at my pistons through the exhaust ports for signs of scuffing ect...

figure with 10-58's , black green primary,black purple secondary and 19-42,slp pipe and can,my wifes D700 would pull 8200 all day at 9000 ft.

 

[davermk]

What is it hitting with 58's? what is the condition of your belt? also a buddy of mine changed plugs and gained a 200 in RPMs. Are you in the steep and deep or on the trail? snow conditions makes a big diff. is your ethanol wires pluged in or not? mine hits 8250 on the trail and 7900-8000 in the powder. I do have a PCV and 58's the PCv runs it leaner on top. What spring are you running in the primary?

Belt is in pretty good condition, the sled has only 650miles on it, it has fresh bpr9es plugs. everything on the machine is stock, except for the 10-58's i just put into it. I dont know if my ethanol wires are pluged in or not? "where are they how do i find out" I trusted my dealer to have the sled ready to ride when I picked it up.
when it had the 10-62's in it, I would be lucky to see 7500 rpm on a flat packed trail, in the step and deep more like 7000..
Now with the 10-58's its hitting between 7500 -7800rpm.. so its better.. but still not hitting 8150 where it should be.

 

[davermk]

I know that the primary spring is black i think its 140-330lb. Its whatever came stock, i bought the machine brand new.. As for the secondary clutch I have no idea what spring is in it.. Probably not the right one for the altitude I ride. I guess i will try the secondary spring next to see if that helps also.. The last thing i want to think, is that the motor has an issue.
to tell the truth im not sure if the sled ever did run at 8150. On the max rpm history on the instrument cluster it says its hit 8350, but I sure have not even come close to hitting that while im looking at the instrument cluster

 

[2XM3]

secondary probably has black spring in it...now you should NOT change secondary spring in order to gain rpm, to do that it will require more secondary spring pressure in order for the secondary to not fully shift out, thus killing gear ratio and allowing the more rpm. Now yes sometimes you might want this in order to run a 1:1 ratio BUT thats a very special deal and not what you are after. The primary adjusts the rpm.
Try going to a 19/42 ratio in the chain case,that seems to work best at higher elevations, probably has the 20/42 in it now.But still only a bandaid.
At 600 miles on your sled I really would take the time to pull the pipe and give the pistons a careful looking over.........if ya put some 10-56 in there and don't hit 8200+ on a trail you have a motor issue, be it electronic or internal


On a good note you did pick up rpm going down in weight its when it does not change thats a bad thing.

 

[davermk]

secondary probably has black spring in it...now you should NOT change secondary spring in order to gain rpm, to do that it will require more secondary spring pressure in order for the secondary to not fully shift out, thus killing gear ratio and allowing the more rpm. Now yes sometimes you might want this in order to run a 1:1 ratio BUT thats a very special deal and not what you are after. The primary adjusts the rpm.
Try going to a 19/42 ratio in the chain case,that seems to work best at higher elevations, probably has the 20/42 in it now.But still only a bandaid.
At 600 miles on your sled I really would take the time to pull the pipe and give the pistons a careful looking over.........if ya put some 10-56 in there and don't hit 8200+ on a trail you have a motor issue, be it electronic or internal


On a good note you did pick up rpm going down in weight its when it does not change thats a bad thing.

Ok... well im not a mechanic.. and im not confident enough to diagnose a motor problem. I guess I just need to bite the bullet and bring it to a snowmobile mechanic. Unless you have any other last ditch efforts that someone like myself could try. I did just order the SLP 09-296 silencer, maybe that will help?
The VES valves are scrubbed clean, maybe i have a bad ves bellow or something.
Should I also try a new drive belt?
If i change the gear ratio in the chain case, do I need to replace the chain and both sprockets, like you do on a dirtbike? or can I just put in one sprocket with the existing chain?
Your help is appreciated

 

[2XM3]

just the top gear to a 19 from a 20 tooth, everything else stays and fits well, all o'rings to so no gaskets to buy... pretty easy job as well. Should be some diy's in the forum posted here.

Do you have a GOOD dealer nearby? With a known mechanic that can give it a look for you?

 

[force it in]

thats just what mine did i put fix kit in power addiction heads in runs no problem i bet your moter is gone and yes 62 pol weights 8200 at any att. now good luck

 

[sled_guy]

Take it to your dealer... or I should say, a good dealer.

It could be several things, a check of the pistons takes just a few minutes by pulling the exhaust valves. My money is on that, but I don't want to be mean.

It for sure could be the TPS... a TPS out of adjustment and it won't pull RPM.

All other things stock, dropping to 10-58s, you should pull 8100 at 10k no problem.

sled_guy

 

[Himark]

yes 62 pol weights 8200 at any att. now good luck

dis-agree. Sleds stock wont pull 62 at 10000 feet in the steep and deep. They will trail riding or low load.

 

[2XM3]

agreed, 62 would be to much weight.

I will also add that the problem you are having is pretty much the exact same thingI have seen on the 4iq engines I rebuilt, rings are just going south, won't pull rpm any longer then piston knocks a skirt off....and your pretty much at the "magic" number mileage wise for the problem as well.
I would really suggest a leakdown test to see what your ring seal is like.. if it over 15% ;leakage hot...pull it apart and look into the "fix" kit before you have a major issue.


Oh Dave read the 2 threads I refreshed above on cylinder skirt clearance and dear polaris....good info

 

[force it in]

i would bet if your moter is good condition you would notice a change in rpm and yes stock 62 might be heavy but with my combo the fix and power adiction heads it will pull 8200 all day long just like it did when it was new out of craite

 

[Himark]

any updates on this davermk?

 

[2XM3]

i would bet if your moter is good condition you would notice a change in rpm and yes stock 62 might be heavy but with my combo the fix and power adiction heads it will pull 8200 all day long just like it did when it was new out of craite

the 2008 dragons with 08 program and high compression single ring pistons really pulled HARD...ran 64's or 66's in that one at 8200. Killed it after the "update" power wise.

 

[MARV1]

Switch to Champions...

 

[grizzlytwin]

what i have noticed with my '09 dragon is that it loads up and then when you hit it the rpm's will go to 79 - 7950. Give it a few hard pulls to that rpm then it cleans out and will pull 82 - 8250.

have just begun to look at why it loads up like that but possibly these low rpm issues are a fueling issue?

Anyone got any insite into mine? This '09 had all the '10 updates etc done on it. 400 miles. SLP pipe, carls helix with OE weights.

thoughts?

 

[WyoRMK]

Like Force It In said, mine did the same thing. Check the pistons for scuffing.

I too put the FIX in and could not be happier!

it is the sled I bought before the "polaris update"!

 

[CFH406]

If your leak down test shows you your pistons are ok try MTX belly buster weights and blue pink spring in you primary. Black silver and a 56.40.36 helix in your secondary. I had the same problem only pulling 7600 to 7700 in the deepsnow and climbing. Ride 8000 to 10000 feet all the time. With that set up i can pull 8300 trail and 8000 -8100 climbing. Sticky wet snow about 7900. Mine is geared down as well to the 19 tooth on top. The polaris dealer in casper said a different helix 58.40.46, but i had the other one so i put it in to try it and it seems to work. I tried the 10-56 trick and it didn't do anything for me. The helix was the ticket. Let me know if it helps.