sockeyerun
Test Dummy
My buddies 2000 7mm is reving to 9000+. right now the setup is: completely stock primary w/ 10.9 inner and 4.5 outer rivets. secondary has a 47-43 helix(does the same with the stock 43 helix to) and a green spring wrapped to 80. The motor is stock except it has two layers removed from HG. stock single exhaust with a Bender can.It has been stretched to 151 and has reverse. He just added the 4.5 to the tip as it had a lighter rivet in it( I'm sorry I can't remember witch one it was) and it did not change the rpms at all. I did notice that his secondary is slipping on the top end (rubber marks at the bottom of the sheaves). Can this be a problem with clutch alignment ? Thanks Soc
taylzee
New member
My guess would be something in the clutches. I would pull them both and hve a good look at the springs, bushings, ramps, etc. If he added weight to the primary and had no effect on the RPM, it would stand to reason that there is an issue in the clutching.
4.5 gram inner; 2.4 gram outer; 70 gram wrap at 6k elevation. if he,s still overrevving he,s got clutch part issues.
sockeyerun
Test Dummy
Turk our elevation where we ride is basically around 800-1000 ft.. would the tip weight still be the same? Also a ? I have basically the same setup except still 141" and no reverse and I'm running 4.5 in both holes. I have ran both those helixes and was running around 8600-8700rpms. What is it that causes the belt to spin in the secondary on the top end?
He might have a pooched bushing or worn out plastic pucks in the secondary. Even with that helix that sled should pull 4.5,s in both holes at 1k elevation.
sockeyerun
Test Dummy
Turk, Thats one of the first things I did notice that his pucks where highly worn and were replaced. But the problem is still there. Which bushing are you referring to? Thanks alot for you help, once again. Soc
ps. I'm really liking the 51/43 you suggested for my 7MM, pulls real hard and rpm's are steady at 8400.
ps. I'm really liking the 51/43 you suggested for my 7MM, pulls real hard and rpm's are steady at 8400.
Check the main bushing in the secondary itself. If the pucks get worn too bad then that bushing can get partially pushed out or worn thru. I would try loading 4.5 rivets in both holes & have a close look at the whole secondary.
sockeyerun
Test Dummy
OK, now I'm really confused. Pulled the primary and had it checked by our dealer. Rollers were to specs,etc.. now have added 4.5 to both inner and outer. Secondary bearing is fine and have replaced the pucks. It's still reving to 9200. Would a weak primary spring do this? His sled is set up exactly like mine right now except the helix. If I change to his helix(47/43) it only raises the Rpm's by 300(8700). When we changed the pucks it quit leaving black in the bottom of the secondary. Confused,Soc