94 Polaris indy 440 SKS new addition - Snowmobile Forum: Your #1 Snowmobile Forum

SurgeDS · 09-22-2009, 11:58 PM

Just bought a 94 Polaris indy 440 SKS for $300 bucks.... Needs new seat and one of the cylinders has a 60 psi compression the other has 110, therefor its impossible to start at times. It has an extended 1.5 x 136 track on it in nice condition with tunnel extensions. Only problem is the engine. I will probably have to replace the pistons and rings on this bad boy. My question is, where can i find the best deals?

I was looking at sledparts.com they seem to have the best prices. What do you guys think? SK1123 - Polaris 440 (67.75/Pro-Lite/2343PS)

Let me know if theirs a better deal out their. I am also looking for a new seat if someone knows where to get them..... I prefer used, trying to save $$$$. Also looking for a 144" track for my other SM if someone has a used track, let me know, thanks.

**RJ Gleason** · 09-23-2009, 01:08 AM

Which cylinder is low, the clutch side?

SurgeDS · 09-23-2009, 10:21 AM

No i believe its the one by the brake side. Why does it matter may i ask?

**BC_Dan** · 09-23-2009, 11:56 AM

Lots of times, a cylinder goes down because of a lean condition. The PTO side crankshaft seal is more prone to failure than the MAG side seal. When the PTO side seal goes out, that side goes lean, that cylinder/piston gets damaged and loses compression.

**RJ Gleason** · 09-23-2009, 12:18 PM

It's important to know this because you can rebuild the top end and then have it repeat the problem because the cause was not addressed.

SurgeDS · 09-24-2009, 02:04 AM

I will check which cylinder is acting up. I will get back to you ASAP.. Thanks a bunch for the head up!

Is the seal usually easier to replace and cheaper?

**RJ Gleason** · 09-24-2009, 08:23 AM

Replacing the clutch side seal is fairly easy since you only have to get the clutch off to do so.

Stagesrt4 · 09-24-2009, 09:53 AM

are the wiesco top end rebuild kits OK to use?

my mechanic says they tend to expand alot more than your average piston, and recommends just using Polaris parts...

**RJ Gleason** · 09-24-2009, 10:40 AM

The Poo engines tend to not like the weisco pistons because they are forged with thicker skirts, OEM is the best replacement. SPI makes a good replacement too

SurgeDS · 09-25-2009, 06:27 PM

So if it is the cylinder that's away from the drive belt, how do i double check if its the bad seal instead of a bad compression because of a worn ring?

**RJ Gleason** · 09-25-2009, 07:19 PM

To see if it's a ring, do a compression test, then put 3oz of oil into the cylinder and roll the engine over slowly one turn. Do compression test again, if the reading goes up, it's rings, if not it's probably the piston.

To check the mag seal, take off the flywheel and look for any sign of oil on the stator.

SurgeDS · 10-01-2009, 08:11 PM

Quote:

Originally Posted by RJ Gleason

To see if it's a ring, do a compression test, then put 3oz of oil into the cylinder and roll the engine over slowly one turn. Do compression test again, if the reading goes up, it's rings, if not it's probably the piston.

To check the mag seal, take off the flywheel and look for any sign of oil on the stator.

If its a bad/good mag seal, bottom line i still need to replace the rings or piston on the snowmobile right? Its not like the mag seal is causing the compression 60 psi right?

Either way if i am going to take off my flywheel and look for any sign of leaking oil, i might as well just replace that seal just to make sure right?

**RJ Gleason** · 10-01-2009, 08:18 PM

A leaking seal will cause it to go lean and hole the piston or chunk the edge enough to freeze the rings. You will have to open it up to be sure.

SurgeDS · 10-01-2009, 10:55 PM

is there is web site of some sort that tells you the piston dimension size and also the ring size for my Polaris 440?? i want to see what the difference in between original rings and currently mine..

**RJ Gleason** · 10-02-2009, 08:58 AM

Browse

SurgeDS · 10-02-2009, 12:29 PM

What a helpful person you are, thank you very much! Kudos to you my friend!

I will toss you an update, probably going to do the oil test today.

SurgeDS · 10-02-2009, 08:28 PM

OK finished the test today....

Stock, the cylinder that's on the belt side gets 110 psi. (normal? should i replace rings too while cylinders are apart?

The cylinder that's away from the belt gets around 60 psi.

------

poured 3oz of oil into the 60 psi cylinder and cranked it by pulling all the way (normal start way).. I got a reading around 50 psi and dropping but then noticed that my seal on the tester was leaking where it hooks up the cylinder. The gasket seal pitched and was sticking out from one side instead of being even (harbor fright $25 dollar tester what do you expect)..... So i added 1.5 oz of oil and this time corrected the problem by re-tighten it nice and firm and got a whooping reading of 140 psi! Wow never thought oil would hold that much pressure.

So looks like i just need the rings then?

If i had a gasket leak by the flywheel wouldn't i notice it with-out taking the flywheel and everything else apart if the engine was super clean??

Other cylinder has 110 psi, is this original psi for these Polaris 500 engines?

**RJ Gleason** · 10-02-2009, 08:34 PM

135/140 is normal after break in period.
You will have to remove the flywheel at least to check that seal unless there is a lot of oil/gas inside the recoil housing.

SurgeDS · 10-15-2009, 12:35 AM

Pull the engine off the other day. Didn't get a change to take anything apart on it really. The engine is Polaris 500. Could someone help me decode it from which year and it came off and possible model? Also where is the seals located? Both sides right? One on clutch side and one on crank side? I assume i will have to split the whole block apart just to check them, might as well replace them since the engine is that far apart.

Here is what i pulled off from the block of the engine. Motor # 99-00904 Cylinder Casing: EC50PL17 I also have other numbers if needed.

I looked through exhaust output and i notice the piston is pretty scratched up, not a good sign. I will post pictures once i start taking it apart to help others.

Any help along the way is appreciated, this is my first snowmobile engine that i will be taking apart. I just found this new snowmobiling drug last year and i am not no expert on these things. Now if you ask me about the dodge Cummings 5.9 litter diesel engine, then you will speaking my language.