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My first four stroke snowmobile. Road it on the trails last weekend and was engaging around 4400rpm is this what everyone else is seeing? Seemed a little aggressive on the trails.
 

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My first four stroke snowmobile. Road it on the trails last weekend and was engaging around 4400rpm is this what everyone else is seeing? Seemed a little aggressive on the trails.
I'm sure there are many suggestions for changing clutch engagement that will be offered, but with my Z1 I had the yellow/white spring in it stock and my clutch engaged at about 4000 rpm, being a 4 stroke and making torque down low, I figured I would just switch to the gold spring. 0646-433 My engagement is now down to about 2700 rpm and I don't bounce off the rev limiter in powder. It performs much better now.
 

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The stock spring is 120/285 l take it I just want to lower the the first number. Thanks for the input.
 

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How many miles on it? The buttons on the new clutches , some are real tight at first. I’d try to ride it if you don’t have many miles on it. Maybe they will loosen up some
 

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How many miles on it? The buttons on the new clutches , some are real tight at first. I’d try to ride it if you don’t have many miles on it. Maybe they will loosen up some
I only have a 100miles on it so far. Thanks for the info.:thumbsup:
 

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My first four stroke snowmobile. Road it on the trails last weekend and was engaging around 4400rpm is this what everyone else is seeing? Seemed a little aggressive on the trails.
I've got about 60 miles on mine and I'm kinda surprised of the higher engagement as well. Waiting to put more miles on to see how it breaks in. It's eventually going to get tuned and clutched, but want to play with it stock for a little bit.
 

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4400 is where the 17 turbos came in at. I installed Ron Ward's clutch kit and it dropped down to around 3000 and was a vast improvement in the clutching. After 2000 miles my buttons were still tight. I pulled the clutch apart and sanded the backside of the buttons down until they were still making contact but the clutch was buttery smooth. Of course within a week of doing it they recalled the clutch so I did it again with the new one which was even tighter to begin with.
 

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I'm assuming that this spring will engage at a lower rpm and have the same max rpm as stock? Clutching for dummies here, what happens if you change the finish rate higher or lower on your primary spring? I'm assuming higher finish rate would equal less max rpm if nothing else was changed and a lower finish rate would result in a higher max rpm?
 

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I'm assuming that this spring will engage at a lower rpm and have the same max rpm as stock? Clutching for dummies here, what happens if you change the finish rate higher or lower on your primary spring? I'm assuming higher finish rate would equal less max rpm if nothing else was changed and a lower finish rate would result in a higher max rpm?
Lower initial rate equals lower engagement. Higher finishing rate delivers higher maximum rpms. Assuming the earlier post stating a finishing rate of 285 is correct, then a 300 would raise max rpm. The 300 spring has a stiffer finish than a 285.
 

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A higher finish rate equals more rpm? To me it seems like a stiffer/higher finish rate would equal less rpm because it would be harder for the engine to compress it?
 

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A higher finish rate equals more rpm? To me it seems like a stiffer/higher finish rate would equal less rpm because it would be harder for the engine to compress it?
Higher finish rate means it needs more centrifugal
force to compress it, more centrifugal force comes from more rpm.
Or more weight in the primary weights. One directly relates to the other.
 

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No. Stiffer spring all else equal means the weights won't shift the clutch as far, resulting in a lower ratio, which means less load on the engine, which means higher rpm. Get Olav Aaen's clutch tuning handbook.
 

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Discussion Starter #17
20171230_143920.jpg
Lower initial rate equals lower engagement. Higher finishing rate delivers higher maximum rpms. Assuming the earlier post stating a finishing rate of 285 is correct, then a 300 would raise max rpm. The 300 spring has a stiffer finish than a 285.
The spring is 120/285 as per the spec sheet from arctic cat.
 

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I'm sure there are many suggestions for changing clutch engagement that will be offered, but with my Z1 I had the yellow/white spring in it stock and my clutch engaged at about 4000 rpm, being a 4 stroke and making torque down low, I figured I would just switch to the gold spring. 0646-433 My engagement is now down to about 2700 rpm and I don't bounce off the rev limiter in powder. It performs much better now.
In my opinion 2700 is perfect on a 4 stroke, this makes it smooth as silk on take off. My Nytro was 2800-2900 (ulmer clutch kit) and take off was amazing. My 7000 was around 3600-3800 if i recall. Stuck a low start rate spring in and now it takes off at 3000, also made the sled faster from bottom all the way to the top. 4 strokes have the grunt down low, when are these guys (manufacturer) going to stop clutching them like 2-strokes?

Sent from my SM-G935V using Tapatalk
 

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In my opinion 2700 is perfect on a 4 stroke, this makes it smooth as silk on take off. My Nytro was 2800-2900 (ulmer clutch kit) and take off was amazing. My 7000 was around 3600-3800 if i recall. Stuck a low start rate spring in and now it takes off at 3000, also made the sled faster from bottom all the way to the top. 4 strokes have the grunt down low, when are these guys (manufacturer) going to stop clutching them like 2-strokes?

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That is exactly what went through my mind when I grabbed the throttle on the first fourstroke I ever drove. Why the heck is it clutched like a two stroke? cause all it does is dig trenches in the trailer and the shop floor. lol
 

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I too wish my '17 9000 RR had a lower engagement point. It feels like my ZR 800 with a clutch kit, just a little smoother.
 
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