Ski-Dooin' it
Expert
I just wanted to get a feel for what people are doing as mine is alright at best, runs good, and is fun, but just isnt setup properly. its REALLY jumpy.. I can feel it engage then just suddenly shift out, when easing into the throttle to coast around on the trail it legitimately sounds like it has a tranny and shifts up. running stock secondary, 14.5 rollers the large stock yami weights loaded. and forgot hte primary spring, I like the engagement, and runs good rpm, just seems to jump into full shift WAY to fast and dig holes from takeoff..
im geared right at 2:1 and have a 162x2.25x15 track.
I have been told a cat green spring in the secondary is a little stiffer and hsould help it stay in a "lower" drive ratio longer?? also, my helix has a part number on it that ends in 51... could someone have changed the helix before I bought it?? how do you tell what angle it is?
im geared right at 2:1 and have a 162x2.25x15 track.
I have been told a cat green spring in the secondary is a little stiffer and hsould help it stay in a "lower" drive ratio longer?? also, my helix has a part number on it that ends in 51... could someone have changed the helix before I bought it?? how do you tell what angle it is?
dirk_03
Expert
Helix
I think that helix is a 41 degree. The secondary needs a EPI AC purple spring twisted 0-1(like $15 bucks from dennis kirk). The Primary should have a pink/blue/pink spring. I run 8bu-00's(yamaha PN 8BU-17605) with heavy rivets, they are suppose to make a revy two stroke feel to the motor. also running 14.5 rollers.
This is on a vector that should work for 12-14lbs of boost so I would think that the power should nearly be the same as well as your rpm will be the same with the gear reduction. I also was running a 162 2.5 15 wide track
I would try a steeper helix as well maybe a 43-47 degree. I have a brand new yamaha 43 if your interested. I ended up buying a shockwave instead. some like the steeper helix but ulmer said that like a 43 is usually pretty good. Also the shockwave is nice but i didn't find myself adjusting it alot as the sled was very good on rpm with where i started it at.
Also 2:1 gearing may be a bit low. You want to really load the motor, as much as possible with out having the belt slip, maybe gear it for 110-120 mph. And if you get the right clutch setup it should grip the belt perfectly.
I think that helix is a 41 degree. The secondary needs a EPI AC purple spring twisted 0-1(like $15 bucks from dennis kirk). The Primary should have a pink/blue/pink spring. I run 8bu-00's(yamaha PN 8BU-17605) with heavy rivets, they are suppose to make a revy two stroke feel to the motor. also running 14.5 rollers.
This is on a vector that should work for 12-14lbs of boost so I would think that the power should nearly be the same as well as your rpm will be the same with the gear reduction. I also was running a 162 2.5 15 wide track
I would try a steeper helix as well maybe a 43-47 degree. I have a brand new yamaha 43 if your interested. I ended up buying a shockwave instead. some like the steeper helix but ulmer said that like a 43 is usually pretty good. Also the shockwave is nice but i didn't find myself adjusting it alot as the sled was very good on rpm with where i started it at.
Also 2:1 gearing may be a bit low. You want to really load the motor, as much as possible with out having the belt slip, maybe gear it for 110-120 mph. And if you get the right clutch setup it should grip the belt perfectly.
TBird
Expert
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The helix is 45° straight, if it's an 8BV51.
Ski-Dooin' it
Expert
8BV51 is the one thats in it.... 45 isnt to bad.. a little less then I want, but not bad at all. I think just a little stiffer spring should help it out a lot.. like i said, the whole shifting sensation is retarted feeling.. and considering the secondary spring is now 7 years old... could just be sorta worn out as well.. ill be picking up a kitty spring to test out this summer and see if it feels any different. RIght now mine just shifts up to suddenly, kinda loading the motor to much and not just letting it rev, this makes the powerband very jerky.. I have ridden other turbo and sc setups and none are as sudden on the transition as mine.
Ski-Dooin' it
Expert
alright... so I have to laugh at myself, I was able to figure out the whol yamadoo swap, but still have no idea of the affects of the torsion on the secondary...
I dont know what I ahd it set at, it was just twist it sorta stiff and go(i was ignorant). I have a yami white spring in the secondary, and was curious what sorta wrap(in degree) that I should try to run?? Im gonna pick up a epi spring soon, just curious on what degree as the 0-1 thing means nothing to me, I just figured out the whole angle deal on them.
and for the sake of how it works.. would anyone like to shine more info on it?? more twist seems like more load to me? so say jack the load up for the fluffy days, then on the heavy mash potato days, less twist?? or is that totally backwards... either way, I would like the sled to shift out slower, because mine was just digging holes before.
I dont know what I ahd it set at, it was just twist it sorta stiff and go(i was ignorant). I have a yami white spring in the secondary, and was curious what sorta wrap(in degree) that I should try to run?? Im gonna pick up a epi spring soon, just curious on what degree as the 0-1 thing means nothing to me, I just figured out the whole angle deal on them.
and for the sake of how it works.. would anyone like to shine more info on it?? more twist seems like more load to me? so say jack the load up for the fluffy days, then on the heavy mash potato days, less twist?? or is that totally backwards... either way, I would like the sled to shift out slower, because mine was just digging holes before.
givemeaboost
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You need to get rid of those junky stock weights and get a set of 8BU-oo to start with. The secondary is probably set too loose if it's upshifting that quick. Try tightening it up some. There are number on the helix and where the spring goes in the hole on the secondary. I think the helix has 0-3-6-9 on it and the clutch has 1-2-3 on the holes. To set it you have to add up the number from one side of the spring to the other. If you need to set it at 70 degrees you would put the clutch side in the # 1 hole and the helix in the #6 hole . The higher the number will be the higher the tension. Ken.....
Ski-Dooin' it
Expert
yeah, I was reading my service manual and it explain all that jaz.. makes more sense now. as far as weights, I have the 8bu-00 loaded up with the aluminum rivets, so its spot on for RPM with a good belt. after doing some more research, my clutching may not be the issue, it may be my carbs spring setup is giving me a stumble from takeoff, allowing the track to start digging, but have no real turbo launch, making the lag worse, and acting like crappy clutching.
I think I might stick with my current setup, if anything I will be changing to a primary spring with lower engagement, as I like it to roll on nice and smooth. I will try also getting my jetting spot on first, that way I can figure out clutching based on proper power...
another problem is my crappy drivers force me to run the track so tight its kinda like riding around with the brake slightly on, so it doesnt exactly help belt life/heat or clutching... TONS of drag from the track.
I think I might stick with my current setup, if anything I will be changing to a primary spring with lower engagement, as I like it to roll on nice and smooth. I will try also getting my jetting spot on first, that way I can figure out clutching based on proper power...
another problem is my crappy drivers force me to run the track so tight its kinda like riding around with the brake slightly on, so it doesnt exactly help belt life/heat or clutching... TONS of drag from the track.
