Theorhetical clutch/gearing question about 2006 900 RMK

[Dogmeat]

Ok, so if I go with an 18/40 gearing combo, I can use the stock chain?

Also, can any polaris dealer reflash my computer so the speedometer/odometer is calibrated correctly for this change?

Next, what would I have to do to my clutch(s) as a result of gearing it lower? I am assuming I'd have to weight the primary up slightly?

Any info appreciated, thanks.

 

[BIGGDAWG]

well as far as speedo is concerned regearing will not affect it because the speedo reads off of the drive shaft not the jack shaft. and clutching wise i think you will have to add to the primary. most guys are running the 66/44 .46 and 66/42 .46 helix on the secondary with the red black spring and derlin washers.

I am going to try the 18/39 gearing on mine that is a 2.15 ratio and i can use the stock chain and i think the 2.26 ratio is a little low

 

[mountainhorse]

Here is a chart, that I put together for the 2006 sleds. Also the formula for figuring it out below.

Top gear/bottom gear

20/39 74 pitch

20/40 74

20/41 74

20/42 74

20/43 76


19/39 72

19/40 74

19/41 74

19/42 74

19/43 74

18/40 72

(CDx2)/.375 + (TS+BS)/2= pitch

CD=center distance (for you 11.35 on the 2005 (long case) RMK)
TS=top sprocket
BS=bottom sprocket

 

[Dogmeat]

Here is a chart, that I put together for the 2006 sleds. Also the formula for figuring it out below.

Top gear/bottom gear

20/39 74 pitch

20/40 74

20/41 74

20/42 74

20/43 76


19/39 72

19/40 74

19/41 74

19/42 74

19/43 74

18/40 72

(CDx2)/.375 + (TS+BS)/2= pitch

CD=center distance (for you 11.35 on the 2005 (long case) RMK)
TS=top sprocket
BS=bottom sprocket

Is the stock pitch 74 in that case?

 

[GKR]

Nope, the RMK's had a long chaincase, stock pitch is 92 if I remember right.

 

[BIGGDAWG]

i don't know about the 06 but 05 rmks had a 90 pitch chain stock, if you gear 19/43 you need a 92p chain. i have a brand new one and a 43t new gear from team that i think i am going to sell i decided to go 18/39 and use the stock chain.

 

[Dogmeat]

Ok, so let's say on my 2006 I wanted to go with a 19/43 combo ...

Would you guys recommend that for a 151" track, or are you guys who are gearing down primarily running the 159-166" tracks?

Theoretically how much more do you think I'd have to weight my primary up for that combo?

Also, anyone know if the SLP Polaris clutch tools will work on rebuilding arctic cat clutches? heh

 

[FEZ]

2 things

1) I have run 18-41 in a 700 144 for 3 years now and love it.
2) any changes in the clutching should be done in the secondary. You are not making any more power so you really can't pull more weight but you have increased your mechanical advantage so the secondary needs to be changed to accomodate this increase. Adding more inital angle and maybe a longer progression depending on your machine is normal with a large drop in gearing IMO. I found my sled liked more initial and a longer progression to realize the full potential of the gearing.

 

[Dogmeat]

So if I left everything the same but geared lower, I wouldn't spin the primary clutch at a higher RPM?

So what I would wanna do is go with a SOFTER spring in my secondary if I gear down?

 

[bigtoyz]

you'll need to add weight with the 19/43 gears cause you are not loading the engine own as much. I was a 79grams with that gear set. and down to 74 grams with the 20/42 gears. I am also using 66-42-.46/66-44-.46 helix.

Patrick

 

[05 tmk 900]

is this right ?

Top gear/bottom gear

20/39 74 pitch 1.95

20/40 74 2

20/41 74 2.05


20/42 74 2.1

20/43 76 2.15


19/39 72 2.05

19/40 74 2.11

19/41 74 2.15

19/42 74 2.21

19/43 74 2.26

18/40 72 2.22

(CDx2)/.375 + (TS+BS)/2= pitch

CD=center distance (for you 11.35 on the 2005 (long case) RMK)
TS=top sprocket
BS=bottom sprocket