Yellow- wire diameter=.192, Free Length=2.92, Force lbs @ 2.5"=44, @ 1.19"=185
White- wire diameter=.177, Free Length=2.92, Force lbs @ 2.5"=34, @ 1.19"=141
These pertain to factory Polaris springs only. I run a white EPI spring on my sled and it is completely different. The yellow spring should give your sled a higher engagement.
Those numbers don't make sense to me. Those rates are not from primary springs if I am reading them correctly. The primary spring usually run like 140-300, 120-310, etc. There are many different aftermarket companies that make springs and color can be hard to determine after a few years, plus then the manufacturer has to be determined.
What sled are you putting it on? That will help determine what spring you need.
OK, the rates listed above are secondary spring rates, not the primary.
Dark blue: 120-310
The dark blue will make you sled acheive about 200-300 rpm's higher on the top. The Blue is acutally a light blue, or baby blue, almost in color.
The engagement with a 120 is generally pretty low, something like 3000 or so. A lot of the folks seem to like their clutching to engage at around 3500-4000. From my experience, a 140-150 rate works pretty good for this.
I think one of the best things you can do is to make sure your clutch is in perfect working order. Have them rebuilt as needed. Some I've seen are really good with 5000+ miles but the higher the HP, the faster they wear out and get sloppy.
For example: I just rebuilt my cousins from his 600 Classic. Over 6000 miles on the original. The weight bushings where shot allowing the weights to grind into the spider under acceleration. The buttons were in good shape but worn too much creating too much slop between the towers. Some button shims, weight bushings, reshimmed for belt clearance as factory was off from the beginning. Now his sled engages unbelievably smooth and pulls much harder than B4.
Last year, we were on a lake. My 98 600 vs his 01 600 (Both BB 600's). My clutch was tight and new, his old and sloppy-just like his girlfriend...... My 98 would pull away easy. Just kept pulling, he had no chance. BTW-Both had M10 suspensions--so that argument is out... This is just for example. Not getting into chassis design etc....
I think a good all around spring would be an EPI Red on a lot of lower HP sleds. IMHO.
XCSP-RIder--I'm about an hour north of you, and could do your clutch if you don't have the tools etc. Maybe this summer....contact me if needed.
Anyways--since I was up early and nothing to do, there's my quick tutorial on the most very basics of the primary clutch and service. Basics are about all I know.
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