Bring rpms down

Ever since I got back from out west this year I can seem to bring my rpms Down. I was running 9000 with my out west setup which is odd.... As I was only running 7700 out there. Normally it only raises 300rpm. I got it down a hair to 8700 with a different primary spring then I geared it down. And now it hits 8500 and creeps back up to 8700. I'm running Cpc primary and secondary. 65 to 75 weights with speedwerx silver spring (can't find specs on it) rpm doesn't change when I add weight. Backshift is quick as can be and it gets to 8700 way faster than a stock sled will get to 8000. It pulls hard at 8700 but I'm nervous.

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bigjb said:

Boy I wish I had this problem, I can't seem to get mine high enough. What has changed on your set up from last year? I know it's not convention but you could try to loosen up the spring in the secondary to get it to shift up faster and load the motor more.

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i switched brands of twin pipes and i ported it just a hair nothing game changing basically cleaned up casting marks ridged it so that it flows like a cnc ported cylinder and matched my exhaust ports to my flanges. other than that i put on a brand new primary clutch with CPC weights a brand new bdx secondary sheaves and and the CPC conversion kit.

I already have it on the most loose setting that where its shifting best. tried going the other way also and it just made shifts slower. i believe im running a straight 38....ill have to look tomorow its either that or a 36 with the CPC green secondary spring.

Also wyo if it was slipping i would have black marks on my clutches would i not? they are clean as whistle seems to me they are gripping and going, the clutched a cool too. i can make two fairly decent WOT pulls and they are about 82-89 degrees as per my heat gun.

If i could just get it down a little bit i would be happy....i have yet the have another mountain sled outrun me to 60ish (run out of gearing) dam doo guys make me take my head off and measure the bore to show em it aint a BB haha i actually had to do it once

WyoBoy1000 said:

You don't always get black marks,
From your description it sounds odd, need more info or something because you should be falling off the power so hard that if your clutching was close it would pull way down.
Does the speed in a drag race fall off at any certain mph

make sure your set screws in the weights havent worked out, I have seen some weights shift to the side on the pin/bolt and do that

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I know peak rpm should be 8200 with my pipes. You would think that it would fall flat on its face when I over rev (experienced that when running a single pipe) that's why I'm puzzled on this.... It's going against everything I understand about clutching. I get to about 60 mph and it just slowly climbs I always end up letting off at about 65 as my egts start to climb up to the 1180 to 1200 range. I'm thinking about throwing in a set of stock weights again to see how it reacts or even my MDS.... With my speedwerx single I didn't even have to look at my rpms to know I was over revving you could feel it just drop out from under you. I can start this by revving it to 4k slam the throttle and hold the skis 2 to 3 feet off the ground as long as I want until I let off.

I'm going to my shop at noon today think I'll try a set of 73g first and see what I come up with. Otherwise I'll go back to my pin breaking MDS that the set screws don't stay in.

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mountaincat 800 said:

Did you set up the torsion kit or did cutlers? Check and see how much twist is in the spring in degrees. Let us know.

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I worked at cutlers so dale and I set it up. We just preloaded it enough to get the cover on.

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