98 Indy 500 water in crankcase? - Snowmobile Forum: Your #1 Snowmobile Forum

98xlt special · 01-07-2013, 10:01 PM

First off, thanks for your patience...this is a long opening thread to explain all the background.

I pulled my 98 polaris classic 500 out of storage about 3-wks ago. I couldnt get it started, and determined that the crankcase was full of fuel. Thanks to this forum, I was able to learn how to drain the gas. I did that, and was able to get it running on the lift.

To make sure it did not happen again, I decided to pull, clean, and setup the carbs. I followed the manual using the correct drill bits etc. got it running and went for a run on Sunday. It seemed to run fine but would not come off idle quickly enough when I got to a buddies house. I thought the throttle cable was hanging up, so I tried adjust them at his house. We hit the trail to the gas station to freshen up the gas, then to the lake to test it out.

It seemed to run fine on the trail to the lake, and I had it up to 70mph across the lake. It was revving up nice, revving over 6000 rpms no problem. We stopped to take some pictures, and I noticed that now it would not hold an ide. I turned the throttle opening screws about 1/2 a turn to increase the throttle opening, jumped on the sled went about 150 yards, and I heard a pop through the intake. Pulled the hood and saw that the foam snow screen had been scorched.

I tried to start it, and could not get it started. I tightened the plugs too tight in my garage with a normal wrench so could not get them out to inspect with the Polaris tool. I turned the throttle opening screws back and was finally able to get it started, but did not have enough power to move the sled, so my buddy towed me home.

His sled was having trouble towing me, so I kept mine running, revving it to about 4500-5000 rpms to keep the clutch engaged, and providing enough extra power to get us home.

Once home, checked the plugs and compression. The pto plug was shot...had splatter on the electrode, and a peice of junk smaller than a BB stuck between the insulator and metal body. I checked the junk I found in the plug with a magnet it is not ferous. The stator side plug looked normal other than rich mixture fouling from the ride home. The compression was 120 on stator side, and 110 on pto side, which was the same as when I tested the compression when it had the first problem after coming out of storage.

Tonight, I adjusted the carbs to factory spec, got it started, idled ok but it still seemed boggy or flat on the throttle (running with the air box off). I noticed that the PTO carb seemed "poppy" sounding through the carb intake, and fuel was loading up on the carb intake inlet. The stator side seemed fine. I pulled the pto carb, and checked to see if the needle was stuck open and blew out the jets again, put it back to together, but could not get it to stay running. I pulled the crankcase drains, just to see if it was soaking fuel from the constant starting attempts and crappy idle.

The stator drain let loose of a milky looking fluid, and the pto side drained out a dark gray oily fluid.

I have some thoughts as to what is going on, but would like to here yours, since many of you have a ton more experience with these motors than I have.

Any help and advice is appreciated.

JSTROCHER · 01-07-2013, 10:12 PM

I had a sled do the exact same thing and it took 4 or 5 good carb cleaning and needle adjustments to get it running properly and all the fluid in the case was just fuel and condensation and oil and junk from sitting in storage was a lot of trial and error with the carbs to I ally get it going right but it finally went. Try and look at your needle and seats and go from there again.

JSTROCHER · 01-07-2013, 10:21 PM

Oh and once I finally got it running properly it seemed doggy so I had to end up setting up the clutches and the cured the doggy feeling

98xlt special · 01-07-2013, 10:31 PM

Quote:

Originally Posted by JSTROCHER

I had a sled do the exact same thing and it took 4 or 5 good carb cleaning and needle adjustments to get it running properly and all the fluid in the case was just fuel and condensation and oil and junk from sitting in storage was a lot of trial and error with the carbs to I ally get it going right but it finally went. Try and look at your needle and seats and go from there again.

Well, I appreciate the feedback. Your giving me hope and keeping from pulling the head off just yet. All my plugs are somewhat fouled, so I'll try getting some new plugs to see if that cures it.

Also, the jets are all factory 350 main and 45 pilot. The needle jet circlip is set on the third detent ring.

Carbs are total stock setup, which should be fine here in MN....I sit at around 900-1100 ft above sea level, and everywhere I've ridden in MN and WI is no higher than maybe 1250-1500 ft.

Thanks for the hope!

JSTROCHER · 01-07-2013, 10:46 PM

And what kind of plugs are you running??? an yes factory setup should be just fine just ensure there is no debris or gunk or anything in the carbs at all!!! I know you think you may have gotten it all but I did to and found a little bit more crap with every clean. Drain all the junk out of the case and let it sit for a couple days. Make sure there is nothing in the tank as far as debris and whatnot goes and make sure your fuel lines are free if junk and even ice... After it has sat for a couple days try her again pull away at WOT and she should go properly. If it is still doggy look at cleaning up the clutches and you should be golden. But big question is what are you leaning for plugs in it??

mikemalibu · 01-08-2013, 12:18 AM

To quote you " The pto plug was shot...had splatter on the electrode, and a peice of junk smaller than a BB stuck between the insulator and metal body. I checked the junk I found in the plug with a magnet it is not ferous."

Pistons are aluminum so those Arnt ferrious. Have you took a light to look at the piston thru the spark plug hole? I've heard of em burning a pin hole and able to start and run with no power. Also may be worth the while to pull off the y pipe and check the pistons and skirts that way too. Idk if that's a piston port or not but if u have the carbs off u can check that side skirt as well. Just a thought to be sure nothing else is wrong.

98xlt special · 01-08-2013, 12:37 AM

I'm running the stock plugs NGK BR8ES.

I looked in the spark plug hole, and cannot see any burnt spots or holes, and as already noted the compression was ok: 120 and 110 psi, idealy I'd like to see them closer together, but they are within 10%, the usual standard. I looked and felt in the pto side intake port. The piston skirt felt a little rough on the bottom edge, but not chipped or broken. The side of the skirt looked and felt smooth.

One more wrinkle; prior to me buyting it last fall, the guy I bought it from put in a new piston (not sure which side). When running it last year, it ran fine, except every once in a while it would just quit running. Let it sit a while, or change out the plugs, then it would run again. That happened twice in two days on a trip in WI last year. I figured it was just junk in the carbs getting worked up, hence going through them a few weeks ago.

98xlt special · 01-08-2013, 10:24 PM

I checked the compression again today, this time using the WOT method; 130 stator side, and 119 pto side. I readjusted the carbs. The book show the air screw at .75-turn out from seat. The underhood sticker shows 1-turn out, so I used 1-turn. I put brand new gapped plugs in and started it up. It rans for about 15-20 seconds then idled down and quit. I tried to restart with no luck...just fires but wont keep running. I pulled the brand new plugs out, and there is whit milky film on them.

I pulled the exhaust manifold, and can feel a chip and grit on the pto piston, so I pulled the head...sure enough, piston needs to be replaced. I kept going pulling the cylinder block and look at what I found....toast!

Where did that piston skirt go? With this much damage, should I rebuild or look for another motor? The rest of the sled is in great shape.

mikemalibu · 01-08-2013, 11:31 PM

I would rebuild it. If u buy another engine you could end up in the same boat. Unless u know the history of the engine ur buying. I would split the case to clean it out really well and to check the bearings to make shudder they Arnt damaged and replace the seals. Pistons and rings and gaskets Arnt horrible expensive compared to buying a different engine. And then u know what u have. Just my 2 cents

mikemalibu · 01-09-2013, 12:07 AM

You may want to check the bores for excessive wear. Fatigue could cause the piston skirts to break and so could bad design and excessive play between bore and piston.