Yamaha Clutching.

[MMax00]

so mtnviper if he was to shave a little off of each rivet he would then incease his rpm through all ranges? If that is in fact he was looking for. Or if it holds rpm's through all ranges would a spring change the rpm and leave the shift curve even through the entire range?

I to am scouring through the old forums and have gathered a lot of info. SORRY to jump on your band wagon. :exc:

 

[philsummers21]

np MMax00. Only problem with the rivet thing is i dont have any rivets in atm. Running the bare stock weights. Just going to grind the weights down a touch. And im actually good in the mid range so going to try to just grind near the tip. If its like the ski-doo i had 1gram is like 125rpms. Going to try and and shoot for 1.5grams but its hard to get precise when you match all the weights together.

 

[MMax00]

Then try changeing the spring out one size see where it puts you then you don't trash an expensive set of weights. Just a thought

 

[philsummers21]

I moved to an Orange/pink/orange which has a lower engagement but just a tad higher final force and didnt see much change on top but love the lower engagement. I can't find a spring that fits my needs. Anyways its not really trashing the weights, have done this before.

 

[mtdream]

yeah the 35 start springs are GREAT for pow riding!!!

I would shave a little more off your weights i fyour needing RPM's

Lots of people keep overloading their clutches with more and more springs and greater tension, all that does is compromise efficiency...

 

[ruffryder]

I moved to an Orange/pink/orange which has a lower engagement but just a tad higher final force and didnt see much change on top but love the lower engagement. I can't find a spring that fits my needs. Anyways its not really trashing the weights, have done this before.

what is your engagement rpm?

 

[MMax00]

So what elevation is this working for you at? I'm just breaking in and want to start to play with clutching soon. just wondering if that spring is a good place to start. Then work on weights and secondary. I know my 240 lbs riding weight, track lenght and riding style will affect clutching just looking for a place to start.

 

[philsummers21]

I ride 8000ft+ I'm about 250 riding weight with a 162. Engagement i believe was right around 3500. Id have to check again to make sure. Took little over 1.5grams off of the tip. Will test it out this weekend. I can't believe how flat the stock weights are, must be a 4 stroke thing.

 

[mtdream]

I ride 8000ft+ I'm about 250 riding weight with a 162. Engagement i believe was right around 3500. Id have to check again to make sure. Took little over 1.5grams off of the tip. Will test it out this weekend. I can't believe how flat the stock weights are, must be a 4 stroke thing.

Nope, it is a factory thing...if you want harder hitting, try going to 14.5 rollers, and possibly the 8-BU-00 weights...it is a very aggressive profile...

you might end up having to shave weight off the weight itself, but will hit HARD...it is what I run on my boosted sled, but I run it loaded up with weights/rivets...

I would bet the O-P-O spring has a slightly lower engagement than 3500...mine starts to engage right aroun 3k...is fantastic for creeping on the snow...

 

[Mtnviper]

so mtnviper if he was to shave a little off of each rivet he would then incease his rpm through all ranges? If that is in fact he was looking for. Or if it holds rpm's through all ranges would a spring change the rpm and leave the shift curve even through the entire range?

Yes, that is correct in most cases. Although sometimes a weight can be more sensitive to mass change at one end or the other.
For example it may take a 1 gram change to make a 100 rpm difference at the tip. While it could require 1.5-2.0 grams in the heel to change 100 rpms.
It depends on the weight profile, spring rate and helix angle(s), to know how much a certain set-up will react to mass change.
Main thing is to test and tune. Making one change at a time and taking notes about how the clutching progressed, to get most out of your sled!

 

[philsummers21]

Engagement might be lower then 3500. I just know it was alot better then the gwg. I always try to get my engagement lowest as possible. I might try some of those weight Mt Dream since hopefully someday ill be boosted anyway.

 

[ruffryder]

I would bet the O-P-O spring has a slightly lower engagement than 3500...mine starts to engage right aroun 3k...is fantastic for creeping on the snow...

what are you running now? I thought the O-P-O was a very low engagement spring already? You running a P-B-P spring?

 

[philsummers21]

I believe MtDream is running an Orange/pink/orange as well.

 

[NytroLou]

This is my 1st posting. I have a stock 2008 Nytro MTX. I ride mostly powder with moderate hill climbing. I'm frustrated that the ArticCat & Polaris pass me on hills while I'm stuck. I pull 8200/8400 RPM and seem to lose power as I'm sticking. I would like to change my primary clutch set up. I have G-W-G spring, 8FS00 weight, no rivets & 16.5 rollers.
My plan is the go Y-S-Y. Or should I go O-P-O?
Grind weights. Should the material be removed at the tip or bush end?
Weight bushing. This is an inexpensive change. What weight?

I would do the changes one at a time & moitor results.

Thanks in advance for any advise.

 

[philsummers21]

Update on my clutching. Took a couple springs with me up the hill and tried them all out on same hill same snow. This is what works for me best now and its spot on.

Primary:
Green/white/green
Stock weights no rivets took off 2.5Grams at the tip. Down to 63grams.
Stock rollers.

Secondary:
Stock Helix (going to get a Shockwave)
Yellow Arctic Spring at 30 Degrees.

With this setup i himarked my friends M8 by about 30ft in 3ft deep snow. It was awesome cause i rubbed it in ALLL the way down the mountain.

When i get a rear skid on this thing its going to be an amazing little sled thats for sure