Swapping for Polaris skid and tunnel

C

chikkenvoicesinmyhed

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Hey everyone,

My riding's done for the season and I found a Polaris 900 (2005) being parted out on CL.

I want to buy the skid and track (159) off the guy to replace my beaten up 136 track and skid (I ride a 99 Mountain Max, triple piped and otherwise pretty much stock). I could use a bit of help:

1. Should I buy his tunnel too? I know nothing about the compatibility (but I have seen others put the 06 Polaris skid on a MM so I am pretty confident about that.) Too much effort for the weight improvement? I've never had to rivet anything before but I'll learn if it's worth it.

2. Whether or not I get the tunnel, do I need to be taking measurements on the Polaris just to figure out how to mount the skid? I will be picking this up a 3 hour drive away so maybe need to bring a tape measure?

Thanks for reading
E
 
skip the tunnel unless its near to nothing cost wise. only good it will do you is for the measurements for the skid placement and perhaps some bracketry. not worth the effort to swap it out, especially based on your admittenence of riveting skills.

what you will need is accurate measures from the center of the driveshaft back to the mount hole for the front arm and top of tunnel down. you will also need front arm mount to center arm mount and top of tunnel down. be accurate and precise.

in your situation, if the seller will allow and the sled is already apart, i would make a template using stiff cardboard or even some thin aluminum. simply hold the template up inside tight to the top of the tunnel and trace all the holes needed for mounting, including the driveshaft hole.(driveshaft and bearings need to be out) for that sled you would need something about 40" long and about 12" deep. usually better than a tape measure, and you can adapt the template to suit your needs.

that sled is borderline years for the large diameter shaft with the 2.86 pitch drivers. be sure it is actually a 2.52 pitch 159 track, or you will have clearance and driver issues. the 900's around here were either 155 or 163, but that could have been the 06 and last version.
 
I'm not sure about using the tunnel, but you do want to get the measurements from it. You need to make some shims using aluminum plate. I installed a 2005 polaris skid, and I used 1/4" plate and routed it to fit around the tunnel reinforcements & the heat exchanger tabs. I set the router to 1/32" then to 1/16" for the final cut. You might want use 3/16" stock so you don't have to do that. There other ways to shim the tunnel, that's just how I did it.
 
I ended up getting the skid, 159 2.52 track, and not getting a tunnel. I think Hartman's tunnel extension is what I'll get too. I am still fixing the engine up so I have time to order some stuff... I've been reading up on things and it seems maybe 2.52" 7tooth drivers would be worth it. Guess I'd have to buy some and press the drivers onto my shaft? Otherwise, maybe 8tooth but change my gearing...

Since the skid was off the machine when I bought it, I didn't get any measurements. Even if I did have them, would that guarantee the right track angle, even on a different sled than it came from?
 
dont do the 7 tooth. not an option in my opinion with the 2.52 pitch and your 99 sled.

actually measures from the donor sled to your sled will guarantee that the suspension will work and cycle like its supposed to. approach angle is up to you, but if it was X degree approach in one sled, correctly matched it should be close to the same in yours.

yours being a 99 proposes a few challenges as it had the junk approach to begin with, but properly dimensioned you will be amazed at the performance. front arm mounts almost 9" back from where it is now. for a good fit and finish, your on the right track with the tunnel extension, you will be happy there. best to research the dimensions for that particular skid, no sense going forward without them. most likely the same mount points as the 163's so be open in your search. also research the validity of an 05 900 with the 159 to eliminate the possibility of a stretched short track.
 
Thanks for the advice. 05 900 159 is on snowmobile.com specs so I think I'm ok there, and going from 8T 2.86 to 8T 2.52 hopefully will make it simple for clearance and gear it down a bit. Now to find measurements...
 
If that track is a 2.86 pitch you can't run it on 2.52 pitch drivers! It won't work and you will curse yourself when you reach that point and it won't go back together. If the lug height is anything over 2" your getting into having to drop and roll the chain case too. Thankfully wahl bros makes a 2.86 7tooth extrovert that fits a yami shaft and a 7 tooth 2.86 is the same diameter as an 8 tooth 2.52. While your messing with the driveshaft I'd pick up the 2001+ that is hardened for extra durability with such a longer track in there.

Please provide more information of exactly what you have, there seems to be some variation in what you actually bought.
 
Backwoods M Max said:
If that track is a 2.86 pitch you can't run it on 2.52 pitch drivers! It won't work and you will curse yourself when you reach that point and it won't go back together. If the lug height is anything over 2" your getting into having to drop and roll the chain case too.
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Thanks for replying, sorry for the confusion, here's the deal: the 136" track I'm replacing has 2.86 pitch, 8tooth. The 159 track I bought is 2.52 pitch. 2.86*8/(2*Pi)=3.64 radius. 2.52*8/(2*Pi)=3.21 radius. 3.64-3.21 is .43inches. So I was just saying that

1) the new smaller drivers I need should give me enough clearance to cover the extra length of my new paddles (haven't got an exact measurement but they seem only a tiny bit longer than my old ones,

2) 2.52/2.86 = 0.88 so my engine will be turning 12% less track per revolution than it was before, and this automatic downgearing should help spin the longer track. Also, since I have 3 pipes, that should help too.
 
you have that bassackwards. if your removing the stock track from your 99 mtn max, its a 2.52 pitch 136 track. 700's had the 2" lug, 600's were 1.5". the 700 would have 8t 2.52 drivers stock. no yamaha ever came from the factory with 2.86 pitch anything, at least not here in the states.

the 159 would have to be a 2.52 pitch as well, mathematically. and that year poo is a 2" lug as well. you will have to factor in a re-gear of the chaincase period, if it hasnt been done yet. 20/42 works well in that sled as does 19 or 20/40 with the longer tracks. stock on your sled would be 23/40 and 70 link chain. dont forget to factor that chain in when selecting gears.

i just finished up a 98 going from 136-151. same sled as your 99, if we are talking 700's. sent it out the door last night with 20/40 gearing and stock clutching. will have feed back next week. however, i relocated the skid so performance wise will vary slightly, but should be similar with the poos skid being almost half the weight of the pro-action.
 
The only time the driver size works out the same is when you are comparing a 8 tooth 2.52 to a 7 tooth 2.86. The diameters are all the same and wahl bros has the specs for all the drivers.

According to the TracksUSA figment chart all rmk's were 2.52 pitch until the new pro ride chassis came out.

I'm still confused why the talk about a 2.86 driver came.
 
Yes it is a 700, and I got the 2.86 number by measuring across 4 paddles and getting significantly more than 10.08 inches.... I'll have to check it again though, I probably misread snowdad's comment above["that sled is borderline years for the large diameter shaft with the 2.86 pitch drivers"]... must have meant the Polaris. I still have some engine issues I am sorting out so I likely will make the track change mid-january. Maybe I'll try to go 20/40 or 19/40 on the gearing.
 
Can you lay the track out flat on the floor? I would measure leading edge to leading edge on adjacent track clips. If there is still some uncertainty you can always check the part number on the track. Make shire you really know what it is before you start buying parts
 
Yep definitely 2.52, I measured 7 paddles base to base and it was pretty obvious :o|... well I guess this makes it simpler. Now to hunt for gears and find a way to get measurements for the mounting points of the polaris skid
 
hey all if you are out there
After a dead year last year I am back at the sled believe it or not... and having a heck of a time getting measurements. There is a lot of contradictory info out there... people say to use JB shocks site for edge skid mounting locations but they don't take into account different skid lengths. Not to mention I don't know if Polaris/ Yamaha have same tunnel heights relative to driveshaft. I'm trying to get this together to go riding soon. If anyone knows how to get that info let me know, the skid was in the back of a pickup when I bought it. Cheers
E
 
Wow, 2 years later? If you want to jump this time, i have several polaris's in the shop, but none with the 159. Couple of 136's, a 151 and a 166. That 151 should be a dead on match for the 159 but i can easily compare and draw an accurate conclusion.
 
snowdad4 said:
Wow, 2 years later?
Click to expand...

Yep 2 years later :). I just rode the sled as is that first year and did other things last year. Should have some snow this year with el nino.

snowdad4 said:
If you want to jump this time, i have several polaris's in the shop, but none with the 159. Couple of 136's, a 151 and a 166. That 151 should be a dead on match for the 159 but i can easily compare and draw an accurate conclusion.
Click to expand...

That would be much appreciated Snowdad. After scouring the net looking for different measurements I think the first measurement, flat of driveshaft to centre of front arm mount, is between 8 3/8 and 8 7/8, and the centre to centre distance for the front arm to rear arm mount is between 30 1/8 and 31 1/8.

I am about to put the skid and track in sideways to see how it fits. But the vertical measurements, from the top of the tunnel, are still pretty unclear since the driveshaft's vertical clearance may be different on polaris vs. yamaha. I have a feeling I'm going to be drilling some holes, installing, then re-doing it when it rides wonky. I'm trying to avoid that but it may not be possible.
 
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So on the edge chassis, I have the front mount to rear mount centers at 28 1/8. Didnt take the time on the 151 for the shaft to front due to a drop and roll. Funny part, it was the same as the 136.

Just reread your first post and you are dealing with an iq chassis skid. I will work on those numbers later.
 
Thanks for checking, I have never figured out edge vs. IQ but it looks like you are right based on this skid for sale http://www.ebay.ca/itm/05-POLARIS-R...ash=item58d3e7d82c:g:Sx4AAOSwI-BWFZ7M&vxp=mtr

Also it looks like he didn't give me the upper bogie wheels, the ones that press on the rear torque arm shaft. I might be able to use the ones from the Mountain Max skid, they are 7" across so I think it'll work if I can take them off.
 
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