• I've received emails and PM's asking me about "Group Buys" and promotions.

    A Group Buy here on SnoWestOnline.com would be a situation where a normal member (non vendor or mfg) personally collects orders from other members. That member then uses those orders to negotiate a better price with the Vendor/Mfg for HIS/HER "Group" of buyers.

    Here is an example of a viable "Group Buy"

    http://www.snowestonline.com/forum/showthread.php?t=269222

    A promotion that has the words "Group Buy" in the title is still a promotion, and from the rules that were handed down to me by Harris Publications is that non-advertisers cannot run promotions or open sales programs on the forums outside of the swapmeet.

    If a members wants to become a group buy manager, maintain a thread and collect the funds and negotiate a group buy... as a member, you are welcome to do that as long as you are not attached to the business of the vendor or Mfg.

    If you are a vendor/MFG and you want to offer an EXCLUSIVE "SnoWestOnline ONLY" promotion that is exclusive to snowest readers, please contact me and you'll be able to put it up in the Polaris forums.

    Also, before any vendors/mfgs get all "riled up" over this know that the moderators are strictly volunteers and do not receive a dime from any advertising $$ spent on this site.

    As ALWAYS, since DAY ONE of me becoming a moderator, I have pioneered, supported and encouraged vendors and mfgs in getting the word out to our readers with "New Product Announcements.

    Have a great season.

    From this point on, all vendors/mfg's promoting Pre-Season tiered sales programs, in the Polaris Forums, that are not paid advertisers will be appropriately moved to the swapmeet section of the forums.

    MH

800 Engine Rebuild -long post-

Goinboardin

Well-known member
Premium Member
Nov 15, 2009
1,370
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Laramie, WY
I'm rebuilding the motor for my 2004 RMK Vertical Edge 800 159", and was wondering about the torque arm and push arm available from SLP. I bought the sled with the wrecked motor this summer, and it looks like the PTO side exhaust manifold (SLP twins) gasket leaked on the bottom side, so the piston went lean and dissintegrated, taking out the rod bearing as well. So the crank doesn't appear to have suffered the typical big block crank woes, but I don't want them to start. I'll be using an engine plate, and have already replaced the torn front PTO motor mount. Just wondering if the plate should be enough to lock the motor down or if I need to get the other engine limiters as well. I may fabricate my own as I'll have about 3 weeks time in MN to use the family fab shop before I head back to school in CO (not that it would take 3 weeks...).

I went with Wiseco pistons, and I will be very careful to correctly set the ring gap and make sure to have adequate piston/cylinder clearance as well as warm the sled up completely before every ride (already have that habit). I'll be sending my clutch to IndySpecialties for his comprehensive clutch (blueprinting?) job. The decompression holes in the cylinders are welded shut too.

Just rebuilt the waterpump, cleaned carbs (checked to make sure they're set fat enough to start with too-340 mains for now), replaced recoil rope, replaced EV bellows and installed new yellow SLP springs. I'll be running 19/43 gearing and otherwise stock chassis. The sled came with SLP air intake kit and twin pipes (with the stinger cans...hopefully not too loud- yeah right). Just put the skid back in after going through all the pivots and installing new hyfax.

I'll be riding from 9k to 13k, though most time will be spent from 10 to 12k. I'll be running the clutch setup that came with the sled first, and going from there: 10-62 weights, black/green spring (Polaris) in primary; 58-40-46 ER helix with a red/black spring (SLP) in the secondary, running a new 080 belt.

Do you all recommend extra venting for the clutches? Do most dealers provide cylinder honing services? The mag side cylinder looks good (no chips in nicasil and no scoring), but its just about free of any cross hatching at this point and I only have a ball hone.

I would love to buy an IndySpecialties bottom end, as it seems to me the only true fix for the 800 crank engineering mistakes. But, as a student, I don't think I can swing the $1800 price tag and still be able to eat (or buy beer). Has anyone ever used a USA Shortblocks bottom end? Or is it just an overpriced big bearing setup? Anyone know what their bearing support plate does? I would assume its a bandaid version of machining in a lockring into the PTO bearing like IndySpecialties, but I don't actually know yet (awaiting email response).

Thanks for your thoughts/opinions/advice in advance and reading this novel of a post.
-Mitch
 

sled_guy

Well-known member
Premium Member
Jul 5, 2001
3,561
838
113
Riverton, Utah
First off, a leaking exhaust flange will not cause the piston failure and rod failure.

Your approach seems realistic... I'm not a fan of the Wisecos, but that's a personal preference.

I've used lots of different bottom end/crank rebuilds. Dan is the only one that offers a warranty of any substance, but as you say, the price is up there. You make the call.

I'm a big believer in the PTO front torque arm. Check the other motor mounts carefully, not just the one you found broken. I'm betting the clutch is in need of good balancing... Dan will take care of that.

Throw that black/green primary spring away and buy either a Polaris almond or an SLP blue/pink and put it in. Make sure you have delrin washers in the TEAM secondary. If the motor is stock and you are running SLP twins you should be able to pull 10-62s at 9-10k, but above that I don't think you will... unless you are a pretty light guy (under 180lbs or so).

I do like extra venting when running the TEAM secondary. There are lots of vent kits available... I put the IQ shock tower vents in and then a set of 2cool side vents in my EdgeRMKs.

Those are my recommendations

sled_guy
 

clutch man

Well-known member
Sep 9, 2009
619
175
43
La pine Oregon
I'm rebuilding the motor for my 2004 RMK Vertical Edge 800 159", and was wondering about the torque arm and push arm available from SLP. I bought the sled with the wrecked motor this summer, and it looks like the PTO side exhaust manifold (SLP twins) gasket leaked on the bottom side, so the piston went lean and dissintegrated, taking out the rod bearing as well. So the crank doesn't appear to have suffered the typical big block crank woes, but I don't want them to start. I'll be using an engine plate, and have already replaced the torn front PTO motor mount. Just wondering if the plate should be enough to lock the motor down or if I need to get the other engine limiters as well. I may fabricate my own as I'll have about 3 weeks time in MN to use the family fab shop before I head back to school in CO (not that it would take 3 weeks...).

I went with Wiseco pistons, and I will be very careful to correctly set the ring gap and make sure to have adequate piston/cylinder clearance as well as warm the sled up completely before every ride (already have that habit). I'll be sending my clutch to IndySpecialties for his comprehensive clutch (blueprinting?) job. The decompression holes in the cylinders are welded shut too.

Just rebuilt the waterpump, cleaned carbs (checked to make sure they're set fat enough to start with too-340 mains for now), replaced recoil rope, replaced EV bellows and installed new yellow SLP springs. I'll be running 19/43 gearing and otherwise stock chassis. The sled came with SLP air intake kit and twin pipes (with the stinger cans...hopefully not too loud- yeah right). Just put the skid back in after going through all the pivots and installing new hyfax.

I'll be riding from 9k to 13k, though most time will be spent from 10 to 12k. I'll be running the clutch setup that came with the sled first, and going from there: 10-62 weights, black/green spring (Polaris) in primary; 58-40-46 ER helix with a red/black spring (SLP) in the secondary, running a new 080 belt.

Do you all recommend extra venting for the clutches? Do most dealers provide cylinder honing services? The mag side cylinder looks good (no chips in nicasil and no scoring), but its just about free of any cross hatching at this point and I only have a ball hone.

I would love to buy an IndySpecialties bottom end, as it seems to me the only true fix for the 800 crank engineering mistakes. But, as a student, I don't think I can swing the $1800 price tag and still be able to eat (or buy beer). Has anyone ever used a USA Shortblocks bottom end? Or is it just an overpriced big bearing setup? Anyone know what their bearing support plate does? I would assume its a bandaid version of machining in a lockring into the PTO bearing like IndySpecialties, but I don't actually know yet (awaiting email response).

Thanks for your thoughts/opinions/advice in advance and reading this novel of a post.
-Mitch
Make sure you have that crank trued too that is more than likely what went bad and it let air in and took out the piston and rod bearing. Repalce all the motor mounts too. Polaris has to good of a piston to not run theres At $151.00 a piston kit. Make sure to run the metal base gasket from Polaris., DO NOT RUN COMETICS BASE GASKET that comes with the wiseco piston set.
they will leak. also make sure to set timing to Polaris specs too (to much will take out a rod). Also even with the elevation you run mix 10% race fuel too with the SLP twin pipes.
clutching run a black purple spring 64-40 helix in the driven (NO DARLIN WASHER) drive clutch green pink slp spring and 60 gram weights ground to exactly 60 grams ( they run heavy)
 
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Goinboardin

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Premium Member
Nov 15, 2009
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794
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Laramie, WY
Update and More Questions

Clutchman, thanks for the tip on the Cometic base gaskets, I'll pick up some Polaris gaskets at the dealer. You suggest factory timing and 10% race fuel to combat detonation, correct? As far as race fuel, which type (octane, brand, etc.) do you suggest?

You say to grind the weights to exactly 60 grams, I imagine the grinding is done to the backside of the weights and distributed as evenly as possible? Or do you drill shallow holes in the backside all the same distances from the bushing? The black/purple driven spring, who makes that? What sort of RPM does that clutch setup run at?

Motor mounts all good now. Sled had 2200 miles on it, so yes the primary clutch needs some work. Actually had to drill the heads off 2 helix bolts to get that out of the secondary (only after breaking my torx bit..dummy, haha).

Where could I find torque specs for engine assemly? I'd prefer a Polaris Service manual, but not sure where to find one.

Thanks again guys.
 

clutch man

Well-known member
Sep 9, 2009
619
175
43
La pine Oregon
Clutchman, thanks for the tip on the Cometic base gaskets, I'll pick up some Polaris gaskets at the dealer. You suggest factory timing and 10% race fuel to combat detonation, correct? As far as race fuel, which type (octane, brand, etc.) do you suggest?

You say to grind the weights to exactly 60 grams, I imagine the grinding is done to the backside of the weights and distributed as evenly as possible? Or do you drill shallow holes in the backside all the same distances from the bushing? The black/purple driven spring, who makes that? What sort of RPM does that clutch setup run at?

Motor mounts all good now. Sled had 2200 miles on it, so yes the primary clutch needs some work. Actually had to drill the heads off 2 helix bolts to get that out of the secondary (only after breaking my torx bit..dummy, haha).

Where could I find torque specs for engine assemly? I'd prefer a Polaris Service manual, but not sure where to find one.

Thanks again guys.
I have been running 110 from are local shell station, I would just make sure it is 110 or better.
Rpm i like to see 8150 and not over 8250 with the pipes
As for the weights yes grind on the back, the whole serfice on the back
the black purple is a team spring.
go to Polaris web site and you can order it or from a dealer too pn 9918587
 

Goinboardin

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Premium Member
Nov 15, 2009
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Laramie, WY
Trying your clutch setup Clutchman, the helix is on sale at Team's website. The only difference is I'm trying the Polaris (or is it a Team spring?) bright green spring (150-340) instead of the SLP green pink (160-340) as a compromise between your suggestion and sled_guy's (he suggested an SLP blue pink 140-340 or Polaris almond 140-330).

I now have 3 cylinders, two stock VES 800 (cast #339) one needs renic, and one rebuilt VES 800 with porting & decompression hole welded shut (also cast # 339). Whats the consensus on the porting, is it finicky jetting wise with twin pipes? I didn't know the one had the porting done when I bought it on ebay and just realized while mocking up the motor last night. Not sure if I should get the bad stock cylinder matched to the ported one & renic'd then sell the good used cylinder or if I should stear clear of the porting. Would I need to run a different head with the porting?

Thanks again,
Mitch
 

Goinboardin

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Premium Member
Nov 15, 2009
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Laramie, WY
Solid 800 setup

The set up I ended up using (that hauls!!!):

-old style 202# cylinders (no decompression holes)
-SLP twin pipes with stinger cans (race pipes)
-Wiseco Pro Lite Pistons
-SLP yellow VES springs
-Clutch balanced and shimmed by Indy Specialties
-Team bright green primary spring
-10-60 weights
-black/purple Team secondary spring
-64-40 helix
-19/43 gearing
-no sway bar
-used stock rear wheel setup but made it a 2 wheel "kit"
-Flo rites in the dash
-Mo Flo M series shock tower vent
-2Cool edge side vents
-SLP air horn/airbox setup
-one peice engine plate instead of straps
-homemade torque arm
-drilled out PTO bearing oil slot
-WRP tough boards
-6" pivoting bar riser
-removed rear rack to make room for snowboard rack
-stock drivers, stock 159" track (series 4), stock skis, stock suspension all around

I've been out with this sled twice now, it works really well and is surprisingly easy to throw around. Today was the first time I've ever been able to boondock, uphill/downhill, I can crawl up a hill for control or fly up it, and with that gearing setup this thing is snappy! The stinger is a little loud in my opinion, but it works. I'm interested to see how long this crank lasts, no wide bearing, but I was meticulous as hell with bearing crush (followed Alsled's writeup on hardcoresledders.com), and has the engine plate, torque arm, balanced/properly shimmed clutch, deeper gearing, drilled out oil hole & cranked up oiler. Sled is at 2240 miles right now.
 
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Oct 28, 2010
5
1
3
43
St.Paul, MN
I broke both of my pto side motor mounts around 2400 miles. At that time I installed the SLP torque arm. I seemed to help a ton. If you ever rev the motor you can see how much it pulls, the arm takes a lot of the pull out and keeps it in place. I lost a rod bearing last winter at 4900 miles. It is the first time I had to pull the motor apart. Mine was due to a faulty needle and seat assm. Hansen Racing in North Oaks couldn't believe how good my crank bearings were. I've ran nothing buy AmsOil Dominator in it since day one. He did my crank bearings (I did not put the wide bearings in either) for me and honed my cylinders out. If I remember right it was $15 a cylinder. He does 90% of all the crank and cylinder work for dealerships in the metro.

Hanson Racing Engines Inc


5 Sumac Lane
Saint Paul, MN 55127-6518
 

Goinboardin

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Premium Member
Nov 15, 2009
1,370
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Laramie, WY
Update

I was too excited earlier this season to really pay attention to what my actual RPM was at with this clutch setup. Now that I've encountered many big hills/pulls that aren't so easy, I've begun watching my tach during the climbs or any wide open runs. Its maxing at 7950 RPM (SLP's dyno charts show peak power at 8200 RPM). I didn't follow Clutchman's exact suggestion, by that I mean I didn't grind the clutch weights to exactly 60 grams, so it looks like he knows his chit.

Just thought I'd write this update in case someone is looking for a good detailed setup to run between 10-12k. Hope everyone's seasons are going well!:beer;
 

izzni

Well-known member
Mar 22, 2009
736
511
93
Vadnais Heights
When I bought by 2002 RMK 800 I rebuilt it, and when I did so I read up a whole bunch on crank failures.

What I read was that the PTO end failures are actually due to casting defects (inclusions) in the crankcase. If these defects were near the PTO end of the case, the case would deform and put extra force on the PTO end of the crankshaft. The extra force would over time cause the PTO end to fail.

What I also read was that this was mainly a problem on crankcases from the early 2000s, very late 1990s. Your 2004 crankcase would be much less likely to have any defects than one from a couple years earlier.

I could be way off base, but I spent quite a bit of time figuring out what I needed to make my sled reliable, and this is what I found.

That being said, you have a 2-stroke Polaris. The rod bearings seem to fail around 5500 to 7000 miles if your crank's PTO end hasn't broken off by then. My sled's a riot to ride, but I'd be the first to tell you that the engine is just plain unreliable. Sure, you could buy a $1800 bottom end, but make a mistake jetting the thing, have a oiling failure, have a piston fail, and that $1800 you spent probably just got trashed. If you do your own labor its cheaper to live with the failures than spend a crapload ensuring the bottom end won't fail and then praying that something unrelated to your bottom end doesn't destory it.
 
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Goinboardin

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Nov 15, 2009
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Laramie, WY
Update

Sled now has 3050 miles on it, so about 850 on the rebuild, runs strong, only real issues all season were worn out clutch weight bushings and right at the end my homemade torque arm broke a heim joint.

Piston wash is a little rich, but nothing rediculous (running 330 mains). I checked the PTO crank end play and measured it at 0.0015" with my dial indicator. Pretty happy with that.

Picked up a few parts for this upcoming season, and I'm sure I'll buy a few more in the coming months. Already purchased: rear shocks (walker evans), anti rachets (Wahl), skis (Grippers), water pump belts (yes plural, keep an extra w/ the sled), and a Boss seat. Soon to come: 174x16x2.5 track, ice age straight rails, anti stab, drive train bearings, SLP's torque arm and stop, maybe SLP cheater head, RSI aluminum rise bars, headlight delete w/ homemade vent in place, billet throttle block, Wilwood master cylinder, relocate switches to dash, clutch maintenance, and snow!
 
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Goinboardin

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Nov 15, 2009
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Junk.

Well with roughly 1500 miles on the rebuild, its junk again.

PTO rod bearing is gone, but it didn't quite lock up.
MAG side piston is beat up top and bottom from debris and melted pretty good.
MAG side crank seal is shot, I can see the crank bearing through the seal.
PTO side piston looks pretty good, just some really light scuffing on the intake side.
Both wrist pins and wrist pin bearings are in great shape.
MAG cylinder skirt is missing 3 half dime sized chunks. These are on the sides of the skirt, not front & back (intake and exhaust) of the cylinder.
The PTO side dome looks like it did this summer, about perfect.
The MAG side dome looks beat up and matches the MAG piston indents.

The day before it let go, my hanging idle had returned. I had recently fattened up the idle circuit so there was no hanging idle, so when it returned I immediately thought air leak. I checked the carb boots and they checked out fine. Nothing wrong with the air box, reeds are fine too.

So I'm not sure what happened. I would like to think the MAG seal went out, leaned out that piston, and debris took out the PTO rod bearing. That theory is supported by the PTO piston showing no signs of deto and the MAG piston being melted.
But I occasionally see the deto sensor go off, so that makes me think I shot myself in the foot by not just spending a few bucks for the less deto prone SLP head in the first place. And that it was the deto that took out the rod bearing, and debris took out the seal, and just before it started to grind to a halt, the MAG piston got a shot of air and burned up.
Not sure. I think the first explanation makes more sense, but I don't really know.
 

judger101

Well-known member
Sep 2, 2008
342
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Washburn, ND
this is why i went to yamaha. sorry for your troubles. i spent more money on my 2000 800 rmk than i care to remember, but it sure was a heck of a good sled besides the shotty motor.
 

Goinboardin

Well-known member
Premium Member
Nov 15, 2009
1,370
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Laramie, WY
Yeah I measured 0.0015" runout on the PTO end of the crank before this season started. Just tonight I measured 0.012" runout on the PTO end.
The only change to my primary clutch was using those little arctic cat weight shims and changing to a different set of Poo weights, can't imagine that threw off clutch balance too much but maybe it did.

MAG end of the crank, about 1.5" from them outer bearing race, measured 0.001" runout. The outermost MAG bearing is toast, I didn't see that before as I hadn't removed the magneto housing at the time of the last post. But the MAG rod bearing looks and feels great, whereas the PTO crank bearings are like new while the PTO rod bearing is totally flattened.

I could see the second MAG crank bearing through the trashed outer mag crank bearing and it was fully in tact.

The bearing crush on the PTO end and the center crank bearings feel just like when I assembled the motor, but the mag crank bearings feel a little more loose. I think the outermost bearing may have spun in the case, but its not too obvious.

The stator housing was full of oil, so maybe when that seal went out the outer mag bearing went dry and that's why it failed. But I could also see how the bearing shrapnel could rip that seal. So what happened first, I have no idea. I suppose it doesn't really matter. Just interesting to think about.
 

Jay

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If a bearing spun in the cases you would see it. I suspect you are right in thinking detonation, alltho maybe the piston failed? bits of the piston took out the mag side? Eitherway it sucks.
 

Goinboardin

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I had the oil line to the PTO side above the intake. The PTO crank bearings are fine. The outermost mag bearing is destroyed as is the PTO rod bearing.

As for piston failure, I don't think that was it, no portion of the piston cracked or snapped of. The mag piston is just beat up from bearing parts getting between the piston top and head. That piston also melted around its circumference, though not all that deep. They were forged pistons, which tend to be on the tough side. At this point I think I had too much timing in it and not enough octane for the race twins/stock 04' head combo, and deto took it down. But I keep going back to the mag seal and outer bearing...did the mag bearing fail and rip the seal, or did the seal leak and the oil was lost through the seal so the bearing went dry then failed?

I was also thinking it would be pretty tough for debris from one cylinder to get to the other cylinder. Am I wrong about that? I don't understand how that would be possible.
 
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Jay

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Crap from one side of the engine cannot get to the other side without making a hole in the process. I think the bearing failed first. If the seal failed first (you say you can see right through it) the mag side would have leaned out and burned down and the bearing would still be intact. With race twins and a stock head any poor quality gas and your going to have detonation and you never know what is coming out of the nozzel at your local station these days. All this is just my opinion, or guess, I wasn't in there when it let go so I can't say for sure. :face-icon-small-con
 
Feb 3, 2012
6
2
3
The reason I asked about the oil line was the statement you made about oil being in the mag housing, I suspected the oil line right away. I made the same mistake when I rebuilt my 800, when the oil line is ran over the intake ports and not under like it's suppose to be it will drain oil by gravity into the crank case, lots of it, to much to be picked up and burned. I was fortunate that the oil was blowing up into the fuel pump impulse line and into the fuel pump itself shutting down the motor. I drained the block by taking out the two plugs on each side at the bottom front of the block, I knew I screwed up when I saw how much oil came out, I rerouted the line and ended the problem.
To be sure, take the two drain plugs out of the bottom of the block, I'm sure you know where they are, if your block is full of clean unburned oil that was the problem.
 
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