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Discussion Starter #1
Hi Guys!!

After hours of searching I have declared this website the best snowmobiler resource out there. I have read many of the posts, and the advice and cameradie are excellent. Even the brand bashing is kept to a minimum. My buds ride Yamaha's but I couldn't pass up the following since my wife and kids come first and I didn't have a lot of money to deal with. Just so you know about my mechanical ability I have rebuilt a few small block chevy's and a couple of boat motors courtesy of my high school auto mechanics training but am new to snowmobiles. Anyway enough about me.

I just bought 97 Polaris XLT Special with only 900 miles on it, garage kept, beautiful condition. Only problem is it has a blown engine. I have been soaking the pistons with oil for a week and gently rocking the motor with the primary clutch but it will not go all the way around even though it moves pretty easily. Looking through the spark plug holes it looks like 1 and 3 are moving but 2 is not. Maybe a broken rod?

My question is can I remove the top end while leaving the block in the sno-machine? It looks pretty straight forward but I want to know if there are any gotcha's and whatever other advice you experts can share.

Thanks in advance
 

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It seems to me as though it would be easier to remove the whole engine so you can put it on a bench or table to work on it.It would probobly be alot easier on your back than being humped over working down low for the duration.But thats just my opinion, and I don't clain to be any master mechanic.

my brain hurts
 

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Welcome to the forum man. In my opinion its definitely the best one out there. Lots of help and info here.

I've got the same sled as you, and I've been very impressed with mine. As to your question, I don't see any problem with taking just the jugs off first to see what you've got in there. I had to do this with the sled my father bought. He got a 1990 Yamaha Exciter with only 1000 miles on it. Unfortunately it had been sitting so long that several mice had taken up residency in the carbs and cylinders. They had pi$$ed and crapped all through it and the pistons were frozen. I just took the head off and sprayed some penetrating oil in, and tapped on the sides of the jugs with a small piece of 2x4 to try and loosen them. Then I put a large strap wrench, with a pipe on the handle for leverage, onto the primary clutch. I then slowly started working it back and forth untill it came free. After that the jugs slid right off the pistons.

Now of course you want to be careful here. In my situation, I knew why the pistons were frozen. In yours, it sounds like you don't really know. So you don't want to put too much pressure on them. But I'd at least give this method a shot to see if it works, with out forcing it too much. Others here might have some other ideas as well. Good luck.



1997 XLT SP 600
"Engage the Mechanism"
 

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Welcome to the Forum!

Heres how i see the deal so bear with me,

I personally would pull just the head and the 3 cylinders (mono block) just so you can see what you have on your hands. Now if you are lucky you will not need to dig any deeper into the engine, but then again.....how has your luck been goin lately. Once you get the cylinders off you can determine wether you will need to pull the rest of the engine out of the sled. If you suspect a broken rod...definatly pull the entire motor, if you think maybe the piston is just broken then just pull the heads and cylinders. If it is just the piston, make sure you have all the bits and peices of it out of the crank case before you put the new piston in. Even if you end up pullin the entire motor the head will eventually have to come off, and it will make the engine lighter to pull if you have to pull it. Hope this helps a little.

Polaris is my way out - Other people just use a door.
 

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Hello, welcome to the forum. I thank you for your comments. Ok, now on to the subject...everyone has thier different ways of doing things. I have never really taken an engine out completely when fixing it. Have taken off the jugs but haven't found the need to completely unbolt it. This holds true with both my XLT and XC 700. I guess you can do it both ways. If you don't mind bending over to work on it, that will work but if you hate to be hunched over and have a lot of time, take it out. Again, welcome to the forum and have a great time here!


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Hello, welcome to the forum, and thank you for your nice comments!

On to your question. I'm with everyone else. If you are just going in for a look, and taking the cylinders off, I would leave it in the chassis, but since you suspect a broken rod, and if you get the cylinders off and a rod is broken, take the whole engine out. That makes it so much easier to split the case to take the crank out.



http://www.bolliger-mabillard.com

I love B&M Coasters!
 

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Discussion Starter #7
Thanks for the input. I had some time last night so I pulled the exhaust and looked in the ports. Good news is all pistons and rods are moving and I don't see any major scoring. Still can't turn motor continuously. I can turn the motor a couple revs one way then it gets stuck. Then I can go back the other way a few turns and it stops again. Turns easy until it stops. Looks like it stops when piston farthest from clutch is trying to go TDC. Tonight I will see if anything is sitting on top of that piston like a piece of sparkplug or something. Wouldn't that be cool?
 

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Although, you say that you see no scoring, you may have a broken ring. It could be sticking out in one of the ports, which will not allow the engine to make a complete revolution.
 

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Discussion Starter #9
Thanks RXLRIDER, that sounds logical. I am being real careful about forcing anything. I know it's just wishful thinking that I'm not going to have to pull the jugs. I'm never one of those guys that get deals like that. I have a friend who bought an XLT that wouldn't run and all he had to do was pull the drain plugs under the exhaust and drain the crank and it started right up.
 

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XLTSP sounds to me like you have a PTO bearing toasted on the crank. Thats what happens when a motor doesn't get fogged in when it gets stored for the summer. Pull the motor and start tearing it apart. If you are lucky there won't be any damage to the case and cylinders. Riley

good day
 

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Originally posted by Riley:
XLTSP sounds to me like you have a PTO bearing toasted on the crank. Thats what happens when a motor doesn't get fogged in when it gets stored for the summer.
[/quote]

This is not entirely true. Not fogging may add to the possibility of having bearings blow, but I have never fogged an engine on any of my sleds in my life, and I have yet to blow an engine. Out of all my sleds, I've never had to tear an engine down yet.

Well, I blew an engine in my '96 XCR 440 SP, but that was due to a malfunctioning oil pump. I purchased that sled with a blown engine, and replaced everything, and it blew after about 200 miles, we found out the oil pump only pumped when it felt like it.

Anyway, that had nothing to do with fogging. Plus if it was a shot bearing, he would either be able to turn it all the way, it wouldn't just stop when a piston is at TDC, or not at all.



Ride the Best!
 

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Ur situation kinda sounds liek aht happened to my fourwheeler this spring. I was ridin it then the engine stuck. Well i ptu it in the shop and was tryin to get it to move with the promary lcutch, i got it free but it owld only turn part way and stop, i had found that a bearing went on my crank, it leterlly fell apart, i dunno if its the same, but i thoguht id share what happend to me

Ride it like you stole it!
 

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Same thing happened to my 1990 Indy 500 (Fuji 488cc liquid). I was driving it, and the engine locked up instantly. I could turn the motor over, but not all the way around. It turned out to be a bad crank bearing on the PTO side.

There are 2 bearings side-by-side on the PTO end and there is a small hole in the block that lets oil into the outer-most bearing. The hole is insuficient at lubricating that particular bearing in some cases and leads to premature wear and thus failure! The mechanic who diagnosed this problem drilled a larger oil passage and also replaced the bad crank bearing. All other bearings on the crank were just fine, in fact, I didn't even rebuild the top-end of the motor. Just assembled it and rode off into the sunset...

It ran great after that! I can't complain though, it had over 6000 miles on the motor. I sold the sled a few years ago, but i wished I had kept it.

You'll notice also, that Polaris has added an external oil line to the USA-built engines. Just look down behind your primary clutch and you'll see an oil line that leads to the PTO crank bearings. So far I have NEVER heard of any bearing or crankshaft failures on the USA-built engines. They are much stronger than previous designs!.......... I once had a '96 XCR 600 (Fuji) that twisted a crank....$$$$
 

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Polaris Man I would say for not fogging in any of your motors you are very lucky if you have not had a crank bearing go bad. It is exactally like Mgea man and XLT said a PTO bearing will cause that exact problem. I fixed 2 90 500 and 1 XLT last year that did that same thing. And 2 out of 3 came from not storing properly. Fogging it in. I fog untill the smoke is so thick you can't see across the shop. IMO Riley

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That's a tough call to make.

I agree, but only to an extent.....

By saying that not storing your engine properly can lead to bearing failure may be true; but also saying that fogging the engine is how to store a sled properly isn't necessarily true. Fogging is definitely a GREAT idea for storage, ( i use it too ) but also just starting the engine every 2 weeks or so will keep oxidation to a minimum because of the fresh supply of oil/gas being flushed through. So fogging is recommended, but not the only way to get the job done. I think fogging is great at stopping the worst area for corrosion, and that is on the cylinder walls.

Not only that, but even when an engine sits for awhile there is still a thin coating of oil/gas on most parts including the bearings; however, over long long periods of time it can run off. So to say that by NOT fogging the engine, your bearings will get corroded is a tough call for anyone to make.

IMO, i believe that these bearing failures are more from excessive wear from heat and friction due to lack of a good oil supply while operating, than it is from corrosion on a sitting engine. After all, if it was corrosion from sitting, then why aren't ALL the bearings going bad? I fogged my Indy 500 every single year, and took great care for it, and the outer-most PTO bearing still went bad. Is it from the owner not caring for it properly? Mabye .........but, I think more so that it is just a design flaw that Fuji made. After all, it's a notorious problem.

Again....IMO.
 

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i have a 1974 panther, it has never been fogged......it has sat all summer, and for awhile all winter, never had an engine rebuild, never had abearing go out, and it still runs like new.......i dont know if there is a difference in "having to" fog in 4 stroke engines, but we have 4strokes that sit for 9 monhts of the year, and havent blown up....so i think it can all be summed up into "shit happenes"

IMHO


When's Winter Coming Back?​
 

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i have never fogged my engine. I had to replace the pto bearing when i got my xlt because of it being run to hard, but my sleds ran great and never had a prob, and i have nerver fogged it. My sled had 6000 when i rebult it, and i gotta nother 2000 on her. So ill see what happens in the future

Ride it like you stole it!
 

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Discussion Starter #18
Just so you know I am paying close attention to what you guys are talking about. (What a great resource) I am becoming more afraid that it is a PTO bearing because after removing the heads and cleaning a large chunk of carbon off the PTO side piston the engine started turning freely and I thought I had found the problem. So, I put everything back together, put in fresh gas with oil mixed so the engine would get good lubrication and pulled the starter cord. It turned over great about 5 times then seized up good and tight. I'm glad it didn't start. Now I'm just going to pull the engine when I get time and go through it.

Any tips on getting the coolant out without making a big mess on a 97 XLT Special?

Thanks again for all the great tips. Hopefully will see some of you on the trail this winter if I get this beast running.

Does anyone make a Snowmobile Fanatics helmet or sled sticker so we can spot one another?/polarisman/../images/users/Polaris XLTSP/xlt.jpg


I attached a picture, let me know if you can view it.
 

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Geeze, I thought you snuck into my garage and took a pic of my sled
except mine has the low cut black cobra windshield. Nice looking sled you've got!

I believe the only way to get the coolent out is by elevating the rear end and putting some sort of bucket under each of the bolts above the exhaust that drain the cylinders. I just loosen one bolt at a time, then tighten it when the bucket gets full. Continue process for all three untill its drained. Also always have a bucket under any coolent hose that you disconect......some rags too. Sorry to hear you have to pull the whole motor out though.

As for the stickers, there was some talk during the end of last season of getting some TUSF (The Ultimate Snowmobile Forum) or Snowmobile Fanatics stickers made up. But I haven't heard anything since then. How about it erick and pman?????



1997 XLT SP 600
"Engage the Mechanism"
 

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Wow! That XLT looks like it just rolled off the showroom floor! Looks good.
 
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