Snowmobile Fanatics banner

how do i get more topend rpm??

2K views 6 replies 5 participants last post by  madcow 
#1 ·
i need a little more rpm on topend, at least 200 more rpm, and i would prefer to not raise my engagement, if possible.

so would i change the weight or shim the spring to do this??

i'd rather not mess with the secondary spring because i've done it before and it seems you do gain some rpm, but you lose mph because it doesn't fully shift-out. (correct me if i'm wrong)
 
#2 ·
You could do a few things. Dont shim the spring cuz it can cause coil binding issues. You could put in a different spring that has the same initial rate, but final rate higher. could put in a gram or two lighter weights, or grind the tips down some on the weights you currently have. Depending on how many miles you have on the sled, you could just put a new primary spring in that is the same as the one you have now. They get fatigued and lose some of their properties which will change the way the clutching acts. A harder compound belt will give you a couple hundred rpm as well. If you need more info, just ask. -Polaris Doc
 
#3 ·
it's a brand new clutch kit to match my pipes, all new springs.

i found out yesterday that they didn't put roller secondaries in my sled until 98, but the guy who had it before me must have put one in then because it has one.

so that could probably be alot of the problem i'm thinking. right??

so i'm contacting my kit company to try to get the 1998 parts for the secondary so it'll work with the roller clutch. I'd rather do that then convert back to a non-roller.
 
#4 ·
i would remove all 3 weights form the drive clutch and grind 1/2g at a time from the backsides of the tips of each weight. you need an accurate gram scale to make sure all 3 weights are the the exact same weight. test the sled out after each 1/2g you remove from the weights. you may end up removing 1 or 2 grams total weight from the ramps.
less weight in your primary will give you more top end rpm.
 
#6 ·
i ended up buying a non-roller secondary and am going to try that.

when i tighten the secondary it gives me a little more rpm, but it seriously lacks top end mph then, doesn't shift out at all like it should.
 
#7 ·
that is normal reaction. you normally tune the secondary to get good shifting without belt slip or binding. and then tune the primary for rpms. once in a while you go back and make small changes to the secondary and then finish on the primary again.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top