Zr900 Clutch Springs - Snowmobile World : Your #1 Snowmobile Forum

zr9er · 01-16-2003, 01:40 PM

03-900 Std 24/39 gearing due to reverse. Anyone try an orange/white primary spring to prevent the overshift and subsequent belt spitting at WFO that you get with the purple? :0: Thanks, Austin

sled-head · 01-16-2003, 01:52 PM

Go to Am snow and ask big al..........The guy knows it all

zr9er · 01-16-2003, 02:08 PM

Have done that. He says it will overrev. My mechanic disagrees. Just curious before I make the change. But I'm not sure if Al knew I have 24/39 gearing before he answered, don't know if that makes a difference. Austin

gearhead · 01-16-2003, 02:28 PM

Austin
What exactly do you mean by belt spitting? I don't think my sled overshifts either. I have a new ZR9 with reverse and the dam 24/39 gears. I was in the case last night trying to put a 25 in but it is not going to happen. I was hoping the 1100 miles on my sled would have stretched the chain enough to sneak in another tooth. We did some radar runs the other day and my sled was starting to overrev (7600+) at 111 on the gun. I could have gone faster with the stock gears. My clutching is stock except the driven has been loosened one hole to shift faster and pull the revs down a bit. It was revving 7400-7500 most of the time. I don't want to buy any clutch parts till I get my SLP pipe next week.

Terry

IRON WILL · 01-16-2003, 03:10 PM

If you go with a spring that has a higher secondary rate you will raise your peak rpms. if you want to lower your peak RPMs there are a few things you can do. #1 heavier weights in the primary. Losen the secondary spring another hole. The other is the helix install one with a higher finishing angle. I'm not sure what you mean by over shifting... Does the sled bog down off the line or do you mean its "over reving on the top end. It would help to know what clutching you currently have to help remedy the problem.

zr9er · 01-16-2003, 08:17 PM

Gearhead: They have confirmed with a stock 900 with the purple primary spring while WOT runs on ice the belt is coming right out the top of the sheaves. They did this with 2 consecutive belts. Apparently they did quite a bit of testing yesterday and said the orange/white is working well and pulling hard all the way through. I guess I'll find out tomorrow, as I am going to try this and see how it works out. If I find rpms are slightly high for shift point, can I correct this with the secondary, or am I then defeating the purpose? Austin SWRules

sled-head · 01-16-2003, 08:40 PM

Your not going to overrev with the orange /white primary........there is only a 5lb difference in the finish rate........I have had the orange white in the F7 and the rpm's are so close that it doesnt show on the tach. I cant belive that the 900 it throwing belts because I never had a problem with my900........I guess they changed the driver to a10 tooth and the new gearing screwed things up......Its a 15 minuit change up and a 20 buck part just go for it

zr9er · 01-16-2003, 08:46 PM

Thanks for the input sled-head.

gearhead · 01-17-2003, 01:58 AM

ZR9 Something weird is happening if the belt is coming out of the sheaves. I ran my sled on ice flat out till it overrevved and the belt stayed on. The spring does not prevent belt spitting, it is how far the sheaves close that could push the belt out the top. If you machined the inside faces near the hub it could spit the belt. Changing springs will have no effect unless you put one in so stiff you cannot close the clutches all the way. Who is talking about belt spitting anyway. Sounds to me like an incorrectly machined clutch.

Terry

gearhead · 01-17-2003, 02:01 AM

Hey Sledhead hows the snow in your part of Sask?

Terry