Primary spring preload numbers

fourbarrel

fourbarrel

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Ok correct me if I'm wrong here but with the primary spring in the clutch the higher the initial preload the higher engine engagement right?For example if a spring with a 45kg rate was replaced with one with a 55kg rate the engagement increase correct?Here's why I ask,a bud of mine called me to see if I had a spare primary spring,he has a 2000 V Max 700 with Bender pipes and clutching.The orange spring in his primary broke into 3 pieces and he wants to get a ride in this weekend.So I looked up the specs for the orange spring and a couple I had here and this is what I found.

Bender orange spring Pre load 55kg
Rate unknown
total force 1354kg
free length 90mm
wire diameter 5mm

Yamaha spring gr/w/gr pre load 45kg
rate 2075 kg/mm
total force 136kg
free length 89.8mm
wire diameter 6mm

I gave him the gr/w/gr spring to use until he gets another orange one because it's about as close to the specs of his as I had.Now I helped him put it in this morning and we checked the engagement only and it was up around 57-5800.Am I thinking wrong here,if the pre load rate is less shouldn't the engine have engaged sooner rather than later?
 
I might be wrong but I think the w-w-w is pretty close to the bender orange maybe need to add a shim or 2.. ....im not sure they all mesure the force at the same length
 
fourbarrel said:
Ok correct me if I'm wrong here but with the primary spring in the clutch the higher the initial preload the higher engine engagement right?For example if a spring with a 45kg rate was replaced with one with a 55kg rate the engagement increase correct?Here's why I ask,a bud of mine called me to see if I had a spare primary spring,he has a 2000 V Max 700 with Bender pipes and clutching.The orange spring in his primary broke into 3 pieces and he wants to get a ride in this weekend.So I looked up the specs for the orange spring and a couple I had here and this is what I found.

Bender orange spring Pre load 55kg
Rate unknown
total force 1354kg
free length 90mm
wire diameter 5mm

Yamaha spring gr/w/gr pre load 45kg
rate 2075 kg/mm
total force 136kg
free length 89.8mm
wire diameter 6mm

I gave him the gr/w/gr spring to use until he gets another orange one because it's about as close to the specs of his as I had.Now I helped him put it in this morning and we checked the engagement only and it was up around 57-5800.Am I thinking wrong here,if the pre load rate is less shouldn't the engine have engaged sooner rather than later?
Click to expand...

your thinking is correct on the preload, where you went wrong and made the mistake is if its a vmax 700, it has the short cover and spring in it, so thats why the engagement speed is way up because you installed a long spring with a short cover.
 
Oh ok.For some reason I was thinking the triples all had the tall cover which is why I agreed to lend him the spring to begin with.So if both the Yamaha spring and the Bender one are within a hair of being the same length why is the engagement so out of whack?I never checked the rollers or any of the other components of the clutch,my bud never pulled it from the sled he changed the spring with it still on the crank,not the easiest way to do it either.
 
they are not the same length springs, the bender is a short cover spring. If you stick that bender spring next to the green/white green, it(gwg) will be at least 10mm taller then the bender spring is, to use the bender spring in the srx and newer sleds with the long cover you use a thick shim.

your buddy can use the g/w/g spring if you lend him a tall clutch cover for the weekend.
 
hey sorry to high jack this thread but I am having this same issue but reverse. I put a short spring on with a tall cover. until reading this thread I had no idea there was a difference. well until I stared my sled and it engaged pretty much when I hit the throttle. so if I get this right I can put the short cover (off the vmax clutch) and put it with this short spring and it should work. reason I brought this up is because I bought a mm700 clutch and thought I could just switch the spring but that is not the case. Again thank you for any info this is an awesome site! love these old snowmobiles.
 
If I understand the way Don wrote his reply then yes if you put the short cover on your clutch it should work with the spring you have,or you can add shims under the spring to raise the engagement.2" pvc pipe cut into 1 or 2mm thickness works for shims,it's cheap and easy to work with.
 
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