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Discussion Starter · #1 ·
Hi everyone!

My machine has the SLP cheramic singel, Vforce3, Airhornkit, flowrites and Powder prefilters. Just dynoed it and got 140 hp and 95 ft.lb. at 7700 rpm. BSFC is 0,75 with 440 mains, pilot 45, fuelscrews 1,75, air 1,5, needle in pos. 3. NGK 9 EVX plugs. I'm at sealevel. Very nice powerband and no studdering, just a really hard pull all the way to the top.
The engine only has 830 kilometers on it, so hopefully it will loosen up some more as the odo increases. That's why we left the BSFC a little on the safe side.

What I wanna know is how and why I should change my gearing and clutching to get the best out of the motor.
Gearing ist stock now, 25-40. Primary has black/green spring (stock?) and 66g weights, secondary has a Team helix 62/46/46er (stock?). Don't know what spring as I haven't had time to check yet. The track is a 1,5" CrossCountry Camoplast, no studs. And I'm about 220 lbs.
We're mostly gonna run rough trails and I like to ride hard, but I also like the loose sno. So whenever I can I'm gonna turn off the trail for some powder turns and freeriding. What would bee the best setup for me? I don't wanna be the fastest sled over the lakes, but it would be nice if it ran up to 100 mph at least if possible.

In what way does another helix affect performance? And springs for engagement rpm? It enganges at 3500-4000 right now. 120-340 is the spec for blk/green. Is 120 initial force and 340 fully compressed? Would an almond/blue (150-310) engage at a higher rpm end let the primary compress the sheaves more to make the belt ride higher in the clutch? And so on...?

As I'm new to wrenching snowmobiles, but no fool with the wrenches, I wanna know how it works. I've read a lot here on the forum, but now I have to start asking q's. I haven't been able to ride the sled really yet, but we're going up north next week to get to the snow. I hope this sled is fun! And if it's not I wanna know what to change in order to make it more fun. ;)

I hope you guys forgive me if my grammar and spelling is of, english is not my native language.

Best regards,

Mattias in Sweden
 

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Discussion Starter · #2 ·
Oh, forgot... The highest altitude I'm gonna be at is 2000 feet maybe up to 3000 feet occasionally.
 

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You're not reaching peak RPM. You want to get 8000 RPM out of that motor. You will pick up some more HP once you do that. The almond blue spring like you suggested along with some 10-68 weights should work good.
 

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.75 BSFC is really safe. You can go leaner easily. 430 for sure. The pipe will not work best until hot. Make sure the plugs are BPR, not just BR type. I would only go down to a 41 bottom gear. 140/310 primary spring, 70 gram dalton weights, stock black secondary spring, 3 delrin washers, and for what you want, the stock helix is ok.
 

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Discussion Starter · #5 ·
The plugs are BPR. With 440 mains the powercurve drops of after 7700. Would 430's move the curve up? The guy that did the dynotest said that the enginge will probably pick up some hp as it loosen up some more. Hence the 440 main to accomodate that and be safe. Plugs looked real good and chocholate(?!) brown after the runs. What is it that determines optimum rpm's for this engine?

Why only 1 tooth down (25/41)? Will that be enough? What engagement rpms will those primary springs give me?

Thanks for the advices! Got to love the internet!

A couple of pics from the dyno and garage. Mobile camera... :)
 

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Discussion Starter · #6 ·
And the next... How do I insert more than one pic per post? 100k limit seems low...
 

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Discussion Starter · #9 ·
What color would that 140/310 primary be?
 

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polaris 140/310 spring is almond/ blue. try 66 to 68 weights, stock helix with black/red secondary spring 155/222 rate...note....spring now is made all black by team to avoid confusion with the red/ with black stripe. 3 delrin washers 1 each end of spring and 1 under spring cup. aim for your peak rpm of 7700.
 

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140/310 is SLP spring, blue/yellow. If your plugs are chocolate brown, you are quite rich. They should be tan/dk. tan. The power peak will come up when leaned out. You are PLENTY safe rich with .75 BSFC. Go to 430 for sure. You are not hurting the engine running leaner, I would rather have the engine break in under the loads it usually sees. You do not need to run it on the ragged edge, which would be around 400-410's. Gearing too low does not make the engine work enough. The 800 needs to be loaded like a diesel.
 

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This was one of my best setups with the stock Prox 800
Primary
Polaris Almond-Blue
Polaris 10-68 gram weights

Secondary Team Red-black
Stock Helix--62-46 .46

Gearing 25-40
Jetting 420 mains down to 0
Runs to 8000 rpms.
 

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Discussion Starter · #13 ·
Ok, what engagement rpm would the 140/310 spring give me? And I guess the Polaris 150/310 will be slightly higher in engagment rpm than the SLP 140/310?

What difference would that black/red secondary spring do?

And what differences are there between Polaris weights and Daltons? What makes the Daltons better?

I really appreciate all the advices! :) :beer_cheers:
 

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Discussion Starter · #15 ·
I just checked the driven clutch, it's a black w/ red stripe spring in it now. Is that stock or the 155/222? What is stock spring rate?

Also I have put down an order for the Blue/Yellow 140/310 SLP-spring and 3 Delrin Washers. And 430's Pockets... :thumbsup:

And I measured belt to sheave clearance, .063" with a used 080 belt. Put in a new 080 belt and clearance came down to .031". Gonna take out a .020" shim and that will get me .011" clearance with a new belt. That's gonna work, right?
 

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Dalton weights have a better shift pattern than the poo 10 series, for your application. Your stock spring is black/red, 155/222. But I would change it to a new one, which will be LH wound. The Delrin washers will help with binding, but the LH wound spring will eliminate it. Just listen to the clutch when you open it all the way with the belt removal tool. I will bet you hear the spring making noise. Removing .020" shim should put you close, but you will have to check it once it is torqued down. Also adjust with the weights you are going to use, as the clearance may change, especially with the Dalton weights. Be sure the spider shim stack is centered when you torque the spider down.
 

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Discussion Starter · #17 ·
Yep, it's making noises when rotating belt removal tool. And it's an CW spring in it now. Will have to add to the order mentioned earlier. ;)
I really don't know where to get Daltons from here in Sweden, will check if any of my buddies that travels over the big pond sometimes can pick some up for me. Thanks for the heads up on the spider indexing! :bowdown:
 

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Discussion Starter · #18 ·
Oh, forgot... What kind of difference is there between Polaris 10-weights and the Daltons? You said better shiftpattern, but in what way?

I'm kind of a nerd when it comes to these things. I really like knowing what I'm doing and why. Hope you guys can forgive me for all these newbie questions! :hmm: But hey, if you don't ask you never gonna know! :)
 

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Discussion Starter · #19 ·
Ok, now I got my new parts. Almond/Blue (no SLP available) 10-68 wheights, 3 Delrins and a new CCW Black secondary spring.
And as I put the primary together again after removing a .025 shim to tighten the belt to sheave clearance the whole moving part of the primary didn't move smoothly over the whole range of movment! And I did re-indexed the spider one leg CW to get the sheaves to line up again. If I removed the spider and just put the lid and movable sheave together it moves real smooth. Also if I remove all spacers and just handtightens the spider down directly on the axel and put the lid on it moves smooth. Could the thick spacer between the spider and sheave be worn and cause the spider to tilt slightly and thus making it bind?
And that thick spacer with the collars, where is it on the partslist? I can't find it anywhere? How many shims are there generally underneath the spider. Mine only had the thick spacer and one .025 shim. Can I remove that shim and run it with just the thick spacer? That will put me at a pretty tight clearance with a new belt. But I have too make the clutch glide smoothly first!

Does anyone have any advice? Help... :wacko:

PS. I did check that the shim/spacer was centered as I tightened down the spider. DS.
 

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I would check the button to tower clearance since you re-indexed the spider. You may have to reshim the the buttons to achive .002 minimum clearance for each tower. Closer to .002 the better without going under.
 
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