Primary clutch spring values & Roller diameters

[Dynamo^Joe]

Hello:

I am working on a turbo apex and want to know the primary spring forces for these springs...

blue/silver/blue
blue/white/blue

What are the forces?
Is there any primary springs with lower final forces?

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Are there different roller diameters for the primary clutch?
If so...
what is a stock apex roller diameter
What are the aftermarket ones?...who makes them?



With warm greetings
joey

 

[Turk]

The blue primary springs have the lowest force of anything Yamaha has. I have never seen anything with less total force available from anyone . The apex comes with the smallest rollers Yamaha makes at 14.5 mm,s. Using a b/s/b primary spring & decent aftermarket weights like heavy hitters or supertips your gonna have real low `engagement. Hauck used to make 14 mm aftermarket rollers but not sure if they are still available. Your obviuosley looking at using the softest primay spring combined with the lightest weights; shallowest helix & the less aggressive secondary spring to clutch this thing? Just a heads up; a turbo 4 stroke needs a lot of secondary wrap regardless.....upwards of 28 pounds plus to work properly & not slip the belt in the driven.

 

[Srxspec]

Blue-Silver-Blue
Initial: 35
Final: 101

Blue-White-Blue
Initial: 45
Final: 111

I don't believe anything smaller than the stock 14.5mm rollers are available anymore.

 

[HAMMER]

Howdy Joe -- Remember that's all metric kg, kg/mm, mm

Helpful link:
http://www.totallyamaha.com/snowmobiles/aaTECH/TechIndex/sledTechIndex.html

 

[ptt]

joe,
You've have ran heavy spings force's, heavy wt's on the doo's what makes you want to run "lighter" springs on the yamaha?
weight controls RPM
with more power comes more weight.
Good to have you on the site.
ptt

 

[Dynamo^Joe]

@turk: I am testing some 70+g flyweights for Dale at Dalton.
I don't think using such terms, "heavy..light...large...small". Whatever the spring force are, they are;
I don't know if 70~80g flyweights are heavy or not...

I want to see if I can take apart the primary and look to get a visual of what kind of room there is for moving spider position and flyweight around. I don't know if I can do it, I will look.

@Srxspec: Hey man, howzit goin!
thanks for info. You are the gent I chat with a few times over on sled-hedz about you like track dyno's and I don't? he he he

@HAMMER; Yeah, I use this converter and just plug in the numbers. converts a huge range of quantities mass, area, force ...name it, it converts it.
http://earthsci.org/freeware/freewar/co ... onvert.exe

@ptt: I am being asked to come up with something for 3 sleds. 275hp~325hp

You'll find if you ever get to read any of my clutch dialogue, I don't use the words heavy..light...large...small, I just use the word "required" Im a "whatever works..works" kind of guy. I would not view a 30g vs. a 70g flyweight being light or heavy... whatever works..works

Where you would see me say light, heavy is regarding rpms example. Overrev then the flyweight is too light. whether its 30g or 70g is neither here nor there, just know that what is installed is not-required and need heavier to reduce rpms.

 

[ptt]

@joe Where you would see me say light, heavy is regarding rpms example. Overrev then the flyweight is too light. whether its 30g or 70g is neither here nor there, just know that what is installed is not-required and need heavier to reduce rpms.



Yes you are correct Joe. "required"
Listen to what the personality of sled is tell you.
Aren't we always looking for more (harder) push? (how much harder can the flyweight's push, load the motor)
Are you playing with vast range on the helix?
Vast angle's is a person's perspective, but when I ask, I mean in your perspective.
ptt

 

[Dynamo^Joe]

Are you playing with vast range on the helix?
Vast angle's is a person's perspective, but when I ask, I mean in your perspective.
ptt

vast?
Heh heh, another word that describes magnitude.

Just trying to find the required range of helix angles to reduce clutch heat and stop these primary clutches from cracking.

 

[ptt]

let us know how it works out Joe.
How did the RX-1 work for you?
2-stroke/4-stroke same "theory" applies or no?

 

[Turk]

Running a close to stock secondary set up with stock primary spring (35/111) I need about 72 grams of primary weight with heavy hitter`weights to hold rpm,s at 10 ponds boost. Seems to need about 4 more grams for every 2 more pounds of boost. this is a general average for a guidline .

 

[Dynamo^Joe]

The RX-1 worked out real nice so far. I did that about 3 years ago using Dalton springs/flyweights.
Sent dale a drawing of a helix I wanted, he carved one up for me and finding the right spring forces...Im happy as heck.

Nice motocross engine style throttle response. the engine rpms follow your throttle thumbtip. Mikey ran it on gps and got 11 mph more on this lake..repeatable.
The largest improvement in mph was actually getting the engine to rev to 10300 or 10400 on the tach...therabouts. [i don't remember other than the engine rev'd higher from stock calibration]

Mikey put a 1.5 ripsaw track on it and we did a bit of drag race on hardpack snow; With my 440/800 rev I can only jump him about a 1/2 sled length in front of him and he reels me in so about 70 mph he can slowly overtake me.
I have to say it is something else to hear that rx1 engine screaming, coming up the back of me....wow!
Man I just giggle when I get to drive that sled.

Now he runs Supertuners air kit [i think] and the volume that comes out from the hood - it sounds soooo kewl! After using installing that filter kit, had to lower the primary spring final force to keep the engine rpms at rated... I know it made a difference.

This is my sled...
http://media.putfile.com/S8R-clutch-kit-2
440/800
When I stand right I can keep the skis from coming off the ground a lot and accelerate hard and there is only one sled around here that can overtake me....mikey's rx1. [I snow drag a lot. he he] After doing that about 10 times, you feel it in your legs after walking around. Seeing how my sled accelerates, mikey's rx1, i can only pull ahead of it a 1/2 length...then reels me in.

Were gonna make some helmet cam videos this winter of some drags.

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So I went to Yamaha yesterday and they give me a performance manual 07 I went over to a copy shop and photocopy all the pages....so now I have all the clutch data I need.

Thanks to a lurker here, he called me and advise me what to do and give me a part number for the poster.

THANKS

Joey