94 Polaris indy 440 SKS new addition - Page 2 - Snowmobile Forum: Your #1 Snowmobile Forum

SurgeDS · 10-15-2009, 12:39 AM

I am assuming this is my engine from a polaris 500 and the seals are #7 located here:

http://parts.polarisind.com/images/2498%5C2498031A.gif

Polaris87 · 10-15-2009, 06:06 PM

yep thats them...and you dont need to split the cases to put them in. you just tap them in with the base together.

When you remove the flywheel and are ready to remove to stator. Take notice of a mark on the stator and a mark on the crank case. These two marks have to line up exactly when you put the stator back on. This is your timing so it has to be close...other wise your newly installed pistons wont act as well as you would have liked them to...

If you cant find any marks on the stator and case...make one of your own with a chisel or something.

SurgeDS · 10-15-2009, 06:40 PM

Quote:

Originally Posted by Polaris87

yep thats them...and you dont need to split the cases to put them in. you just tap them in with the base together.

When you remove the flywheel and are ready to remove to stator. Take notice of a mark on the stator and a mark on the crank case. These two marks have to line up exactly when you put the stator back on. This is your timing so it has to be close...other wise your newly installed pistons wont act as well as you would have liked them to...

If you cant find any marks on the stator and case...make one of your own with a chisel or something.

So if i can tab the seals in, i can tab or pull them out with out splitting the case?

SurgeDS · 10-15-2009, 09:12 PM

I finally got a chance to remove the cylinders. Turns out, the piston that had the 60-65 PSI was because the two RINGS where seized to one side of the piston. It was seized IN. Where the rings where seized, the piston has a bunch of little scratches. What would cause this? Long term sitting and then somebody fired it up and ran it? The images are shown below.

As for the rings, once i freed them up, they are pretty much the same size as the one piston that has the 110 PSI maybe a hair smaller as you can see in images. The cylinder sleeves and the piston also seem to be the same size with the exception of the 110 piston being a hair bigger.

What is the best thing to do in this case? New pistons and rings? What would you do? Let me know, thanks.

[i]Piston 2 (60 psi one) Notice the scratches and rings seized.[/I]

Piston size one (110 psi good one)

Piston size two (60 psi bad one)

SurgeDS · 10-15-2009, 09:13 PM

Piston sleeve 1 (110 psi good one)

Piston sleeve size 2 (60 psi bad one)

Two top rings from each piston.

Both rings about same size, 60 psi a hair smaller.

SurgeDS · 10-15-2009, 10:43 PM

I remeasured the two pistons from the piston skirts. I got this reading...... Piston 1 (110 psi) was: 71.68 Piston 2 (60 psi): 71.48

Looks like i will be needing this kit. Best place to get it?? $262.99

SK1064 - Std Polaris Piston Kit. 89-97 Liquid Cooled 500 EC45PL097 engine.

Measured the cylinders bore from the top this time. Got a reading around 71.95 to 72.08 across both cylinders sleeves.

SurgeDS · 10-16-2009, 04:45 PM

hey if i got oil at the bottom of my engine case and if i move the engine to its either sides, is this a good way of testing the crank seals?

SurgeDS · 10-17-2009, 02:19 PM

i was just thinking out of the blue, could it be that the oil pump failed somehow which caused no lubricant for the cylinder? How would i test these oil pumps on Polaris 500 engine?

I haven't worked on two stroke engines much but i did work on some motorcycle engines before and they usually have a bleed screw where you can check for oil while engine is running to confirm oil pump is doing its job.. Those where on Yamaha bikes, not 2 strokes.

SurgeDS · 10-21-2009, 12:24 AM

Ive called 2 Polaris dealers, also salesman at al's parts, nobody can figure out from which year my Polaris 500 came from.

So i clean the piston and rings with light sand paper and put everything back. (i know i know, sand paper and rings don't mix, but so doesn't a ring that's all scratched up.)

So far here is my psi reading.

The one that was around 110 psi now read around 120 psi

The one that was around 60 psi (stuck rings) now reads around 100 psi.

....... Big question is, should i risk putting the engine back into sled and run it this winter? I thought about just getting the rings but then if i do that im gonna need new cylinder sleeves or bore my old ones to get rid of the scuff marks.. I might was well by a new engine repair kit for $300 bucks.

So what do you think, keep it at 100 and 120 psi and see what happens this winter? Take out to the mountain and hope i don't get stuck in the meddle of no where and end up cuddling with the grizzly bear?

SurgeDS · 11-17-2009, 07:09 PM

Snow i ended up buying some SPI pistion and rings and full gasket kit including oil seal set. I got the engine bored 10 over and now all the scratches are gone. The engine looks like was bore 10 over once before because now its 72.50 instead of 72 stock. I also found out its a 1999 polaris 500 engine.

Any advice on changing the seals?

After i put everything together, what is the proper break in for the spi pistons? 10 minute warm up and ready to go? Do I need to take it easy for few hours because of new rings and boring job? Or once its warmed up i can pretty much gun it?