Ski-Dooin' it
Expert
Sled is a 03 rx1 motor, shimmed and a custom midmount turbo in a doo chassis running yami clutches and 2:1 gearing and 8 tooth 2.52 drivers.
I ran 10# of boost for the first half of the season and didnt really have any belt troubles in the cold weather. rodei t pretty hard and would get an easy 300-400 miles out of belts and i was bad about breakin.
now, mid season hits, i descided to turn it up to 14#... the thing is SLAYING belts... even on 10/11# the clutches get smokin hot after just a few short WOT blasts. I had my spring wrapped farther in the secondary and it was way worse, back to 1-0 and shes much better.
clutching is primary
8bu's loaded
green blue green spring
14.5 rollers
secondary
45* helix
cat green spring at 1-0....
alignment is nothing to brag about, but its damn close. when it used to be off, it pull threads only from one side, now it just pulls evenly.
this weekend i tried to run 14# of boost and blew a brand new belt in probably 25 miles... not many back to back pulls. and mostly short ones as well. from ice cold to snow melting hot in probably 15-20 seconds wot.
I put a spare belt on and turned the boost down to 10/11#. it was pulling about 10,100 rpm and was running really well, but i would take a few short WOT rips and the clutches are burn your hand hot. the primary definately feels hotter like its the one slipping. From what i have been told, and what makes sense to me is, needs more weight to run that kinda boost as it cant hold the belt... but the problem is my rpm is a hair low so i dont want to load the motor harder. any thoughts/??
I ran 10# of boost for the first half of the season and didnt really have any belt troubles in the cold weather. rodei t pretty hard and would get an easy 300-400 miles out of belts and i was bad about breakin.
now, mid season hits, i descided to turn it up to 14#... the thing is SLAYING belts... even on 10/11# the clutches get smokin hot after just a few short WOT blasts. I had my spring wrapped farther in the secondary and it was way worse, back to 1-0 and shes much better.
clutching is primary
8bu's loaded
green blue green spring
14.5 rollers
secondary
45* helix
cat green spring at 1-0....
alignment is nothing to brag about, but its damn close. when it used to be off, it pull threads only from one side, now it just pulls evenly.
this weekend i tried to run 14# of boost and blew a brand new belt in probably 25 miles... not many back to back pulls. and mostly short ones as well. from ice cold to snow melting hot in probably 15-20 seconds wot.
I put a spare belt on and turned the boost down to 10/11#. it was pulling about 10,100 rpm and was running really well, but i would take a few short WOT rips and the clutches are burn your hand hot. the primary definately feels hotter like its the one slipping. From what i have been told, and what makes sense to me is, needs more weight to run that kinda boost as it cant hold the belt... but the problem is my rpm is a hair low so i dont want to load the motor harder. any thoughts/??
I would try a stiffer primary spring. Then start throwing weight at it. Maybe a Y-S-Y. Also which 8bu's do you have the 00's or 10's? Your secondary is overpowering your primary. You should always tune peam RPM with your primary. That said, start by running a straight 47 with a white secondary spring at 70. Then start tuning your primary. Sounds to me your secondary setup is to agressive, or your primary is not agressive enough. You need to find that happy medium, with that, clutch heat will dissipate. See here for stock Yamaha clutch weight and spring specs. http://totallyamaha.com/snowmobiles/aaT ... prings.jpg
Ski-Dooin' it
Expert
im mad, i had a white spring, but it was 8 years old so i tossed it when i swapped to the cat green right at the begining of the season.
due to the weird nature of the cat springs and how it fits in teh secondary, to put it on 1-0 it has a bunch of wrap on it.. was a 2 person job, i am going to play with holes and soften it up a bit as i think i just have it way to stiff. I will report back as soon as I figure I give it a whirl.
tons of mountain guys on snowest running very similar setups with no issues. reducing secondary preload seemed to help a bunch. it made it pull a hell of a lot harder, so im just gonna soften it as much as i can.
due to the weird nature of the cat springs and how it fits in teh secondary, to put it on 1-0 it has a bunch of wrap on it.. was a 2 person job, i am going to play with holes and soften it up a bit as i think i just have it way to stiff. I will report back as soon as I figure I give it a whirl.
tons of mountain guys on snowest running very similar setups with no issues. reducing secondary preload seemed to help a bunch. it made it pull a hell of a lot harder, so im just gonna soften it as much as i can.
Ski-Dooin' it
Expert
adjusted the green so as to have no preload on it... I think it ended up in the 1-9 holes.
also adjusted my deflection as my belt was a bit to tight.
Ran it all afternoon yesterday on 14# of boost on very hard amazing traction snow. clutches barely ever got hot enough you couldnt hold your hand on for a long time... and it was 40*+ out.. so im very happy with it. on the way down just goofing off and wheeling around off bumps, the clutches were barely warm.
also adjusted my deflection as my belt was a bit to tight.
Ran it all afternoon yesterday on 14# of boost on very hard amazing traction snow. clutches barely ever got hot enough you couldnt hold your hand on for a long time... and it was 40*+ out.. so im very happy with it. on the way down just goofing off and wheeling around off bumps, the clutches were barely warm.
JIM
Extreme
Here is something interesting, I was told by a wise man... NM, he told me he was seeing better track speeds with the bigger stock rollers, so we tried it and we saw a 10 mile and hour track speed improvement !! put your old rollers back in if you have them.. and thank me later
