Wrenching on Sleds

[Tomas.]

Because I cannot find the old thread and the new search restrictions have taken about 15 mins of my life away to try and find it, I am starting a new thread.

I know it is early but I am getting a head start while it is still warm and nicer weather to work in. Although up here in the Edmonton area we have been getting down around 9°c/48°c at night. We have also had a pile of rain this year so I hope precipitation carries on through the winter.

The things I need/want to get done for the season is clutching and shock work.

Some of you may remember that last year I was servicing my 08 D7 SB clutches. I also could not get above 71mph. I was looking on the interwebs and I am starting to second guess my clutch weights. I just put in new 10-62g weights last year (may have 500kms on them). That is the same as what I took out. But for some reason my engine won't get above 7800 rpm. I was looking online and it would seem that for a 2012  rmk 800 elevation 2000-4000ft, it should be using a 10-66g weight.

I cannot find any chart or really any information for my 08 d7. But would switching to a 10-66g or even a 10-64g weight help me reach the 8100-8200 rpms and get a higher top speed or would adding weight be the wrong way to go? Thank you.

[Tomas.]

An edit to the post above as I found the spec sheet for my sled. It says 2000-4000 ft use 10-64g weights and 4000-6000 use 10-62g weights. Would the 2g difference drop my rpm 300ish?

[Big Crappie]

42 minutes ago, Tomas. said:

An edit to the post above as I found the spec sheet for my sled. It says 2000-4000 ft use 10-64g weights and 4000-6000 use 10-62g weights. Would the 2g difference drop my rpm 300ish?

Maybe not 300 but 200 for sure.

[Tomas.]

2 hours ago, Big Crappie said:

Maybe not 300 but 200 for sure.

You it is worth spending another $120 to get those extra 200 rpms?

 

 

New, updated rollers are in!

[Tomas.]

Well my clutch springs came in today. So the secondary got a new OEM orange spring and updated arctic cat hi-temp rollers.

Unfortunately my marks got rubbed off. The internet said to line up the diamond drive logos. Hopes and dreams!! Lol

I forgot my 3/8" torque wrench but supposedly the helix screws are 109in/lbs. So as tight as I dared with a 1/4" ratchet and tried my best to tighten everything evenly. The new screws came from arctic cat with loctite already on them. As the fucking should at $4.23 each and $40 for 9 of them.

Edited August 25, 2020 by Tomas.

[Legend]

The weights are all going to depend on your springs, elevation, condition of clutches and how much hp the engine is making. Added weight pulls rpm down. Subtracting weight adds rpm.

You can find used weights on snowest for $30-$50 USD a set. I have never bought new OEM weights. 

Personally, I would buy new OEM springs, and put 10-64 in if you are at 3k elevation. I'd bet that's real close. Maybe 66, but sounds like you got your shit all fucked up, so who knows.

 

Edit, just get new OEM springs and use your 62s. Whats it call for black/green primary? And I dont remember secondary. 

Edited August 25, 2020 by Legend

[Tomas.]

On 8/25/2020 at 5:44 PM, Legend said:

The weights are all going to depend on your springs, elevation, condition of clutches and how much hp the engine is making. Added weight pulls rpm down. Subtracting weight adds rpm.

You can find used weights on snowest for $30-$50 USD a set. I have never bought new OEM weights. 

Personally, I would buy new OEM springs, and put 10-64 in if you are at 3k elevation. I'd bet that's real close. Maybe 66, but sounds like you got your shit all fucked up, so who knows.

 

Edit, just get new OEM springs and use your 62s. Whats it call for black/green primary? And I dont remember secondary. 

The rpm problem is on my 08 switchback. The clutch I posted yesterday was for my 07 crossfire.

From what I gather, because my switchback 700 has a 144" 2" paddle track, it could be why I am loosing a lot of top speed. But they made an rmk 700 and one would assume that even though they have a longer track than me, they are still hitting the right rpm. Last year I put on a Venom lime green primary spring (150/340) and new 10-62 (what was in it before). I changed the weights because the old weights had worn out bushings and the weights were rubbing on the spider. I also put in delrin washers in the secondary to help with spring bind. I will be pulling the secondary apart this year to replace the spring.

[Tomas.]

Today I changed the primary spring in my 07 crossfire and added the Venom delrin washer kit to stop spring bind. I don't know if the spring was binding before but at a cost of $15, I put them in. I put in a Venom primary spring which matches the original spring rates as the sled didn't have a problem before. It is my wife's sled that the occasional friend uses and it is way too fast for all of them as it is lmao.

The old primary spring was gross. Definitely due for a change but it was actually a hair longer than the new spring but the metal was rusting and probably close to being compromised.

Thank you once again to F7Ben for being a super nice guy and answering all my silly questions. 

 

Now I need to get 7 shocks out of both the switchback and crossfire and get them sent off to Alaska before the gnome goes back to Arizona for the winter lol (only 7 because I had the center shock on the crossfire rebuilt locally last winter because it was blown and not doing much).

[Tomas.]

I was doing some more research and I may have come up with another possibility on my missing rpms and speed on the switchback 700. 

So when I replaced my primary spring last season, there was a huge difference in length between the old one and the new spring with the new spring being considerably longer. The old one was completely sacked out. 

So if my secondary spring is also completely sacked out as well, I would be loosing rpms and clutch movement. I will be ordering a new spring for the secondary and trying that out.

Edited August 27, 2020 by Tomas.

[f7ben]

Uncompressed spring heights really don’t tell you anything although a 12 year old secondary spring is likely to have lost some of its strength.

[Tomas.]

12 hours ago, f7ben said:

Uncompressed spring heights really don’t tell you anything although a 12 year old secondary spring is likely to have lost some of its strength.

Ok. 

On a spring chart, my secondary spring should be 4.7"/11.9cm free length and my spring is 4.25"/10.8cm long in free length. That has to have some sort of a negative effect. I have a new spring on order to replace it. Just stock rates and go from there. 

It really sucks that I still have to wait another 3-4 months before I can even find out what the difference is lmao

[Tomas.]

So I got the clutches all back on the crossfire 600. The only thing I changed in the primary is the spring. I used an aftermarket spring but stock rates. It seems to have an extremely harsh engagement. It still engages at 4000 rpm. Any ideas? The weights and rollers move free with no notches or ridges. 

 

[XCR1250]

Spring with lower pre-tension rate, weights with heavier tip weight or just heavier weights..Thunder Products and others make adjustable weights, it's what I always used for getting engagement and top Rpm's where you want it to be at.

[Tomas.]

I figured out what was going on with the Arctic Cat crossfire primary clutch. I was being a fucking idiot......

 

I went and looked at it this morning and I was going to pull the primary back off. When I went to loosen the secondary to take the belt off, I found that the belt was way down in sheaves. 

 

Turns out my dumb ass somehow managed to get the first and very thin deflection shim cocked when installing the bolt and it prevented the sheaves from being able to close. So there was so much slop in the belt that when the primary engaged, the belt was basically already half way up the primary sheaves. 

 

So I straightened out the shim, put it behind a thicker one and made sure it was installed properly. Works almost like it was designed to do it.

 

I was so focused on the primary, I didn't notice the small fuck up on the secondary. 

 

Lesson learned.

[teamgreen02]

Just a few minor repairs this year. I have the track and chaincase out right now too.  Shocks are out getting rebuilt, putting in all new drivetrain bearings, and installing new track.  That's on top of all the normal shit, cleaning and adjusting power valves, go through clutches, new plugs, new scratchers, new carbides, etc.  Really helps during the season to have all this stuff done and not have to mess with it later.

[DriftBusta]

4 hours ago, teamgreen02 said:

Just a few minor repairs this year. I have the track and chaincase out right now too.  Shocks are out getting rebuilt, putting in all new drivetrain bearings, and installing new track.  That's on top of all the normal shit, cleaning and adjusting power valves, go through clutches, new plugs, new scratchers, new carbides, etc.  Really helps during the season to have all this stuff done and not have to mess with it later.

This time last year I had mine all apart too.  Favorite time of year to wrench.  I absolutely hate working on them once the season starts, unless its in a heated garage.  New sled only has 2 weekends on it, so I'm just bolting on a few new goodies this fall.

[spin_dry]

It’s a good idea to get yourself a digital gram scale and balance Polaris weights. They’re notorious for being different. I saw variances as high as 1.5 grams. Balanced weights make for smoother clutching and less vibration. I’d typically carry three sets of the same weights. For instance if 10-64 weights is what works, I’d have a heavier set that came in at 65 grams. Another at 64, and finally a 63 gram set. Weights used was dependent on changing conditions. 

[Fireball 440]

It's been 2 months to the day since I finished the engine.  Today I carried it out to the garage.