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Discussion Starter · #1 ·
Almost a metal, rattling sound. Not on idle, but on rev up and when the engine backs down. But not all the time. Do crank bearings or rods make noise when they are going/damaged?

I have pulled the clutch, checked the chaincase, checked the recoil and stator. Pulled head and pistons look good and tight, 120 psi in each......................

Do I ride it and see what happens? Do I part it before it goes? Or pull the engine down to the crank?
 

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My PTO side bearing went out and I had no idea it was going. I blew probably 4 or 5 belts before it went, but it never made any noise, everything just stopped all of a sudden.
 

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After going through what I just did, I'd pull it apart and check everything out. What would you be out, a set of gaskets? That's cheap compared to what could happen.

Took mine out for a spin on the lake and it just died. Burned the pto piston. Thought it was ice in the carb because I found water in it upon disassembly. Got cylinder honed and another piston in and low and behold, it did it again. Exactly the same. Tore it down again and found the crank was .010 out of true. The end pto bearing was spinning on the crank (it had worn a groove in the crank), at higher rpms it heated the crank up, melting the seal, taking out the piston. Who would've thunk??? It's costing approx. $500.00 to fix it now.[V]

Oh, and it never made a noise, but all the bearings were smooth.
 

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Discussion Starter · #4 ·
Indeed, I am torn on what to do. I had plans to sell the sled for $1200 then all this happened. I am not intereseted in putting tons of dough into it. I have a few other sleds to maintain as well. I am leaning towards parting it, but it has been such an awesome sled.
 

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my skidoo does the exact same thing, like a chatter from 4k to 3k on the way down. i ignore it lol
 

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Trevdog211 said:
Almost a metal, rattling sound. Not on idle, but on rev up and when the engine backs down. But not all the time. Do crank bearings or rods make noise when they are going/damaged?

I have pulled the clutch, checked the chaincase, checked the recoil and stator. Pulled head and pistons look good and tight, 120 psi in each......................

Do I ride it and see what happens? Do I part it before it goes? Or pull the engine down to the crank?



Crank bearings usually will make a noise or rattle at idle, they also give you a vibration that at certain rpm's can transmit to your handle bars. The only way to really tell is to pull off the head, cylinders then grab the connecting rod and piston looking for ANY play up or down on the crankshaft. Probably best to look into it or it could throw the rod and damage the engine beyond belief.....better yet let your rich friend drive it this weekend.
 

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Discussion Starter · #8 ·
Thanks for all the input. I did try to move the pistons when the head, carbs, and exhaust off. There was no play in the movement of the rods and pistons. Seemed to test out good in my mind.

I pulled the primary and inspect weights, rollers, etc................... but did not see anything unsual. I did not clean the primary or replace any parts. Although, the noise seems to generate from that side of the sled. But it still seems to be more in the motor than the primary.

Thanks for your help and input.................................
 

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"If you have a bearing that is failing don't run it and wait for it to grenade. Its better to have it fixed especially if the top end is still in good shape. The bearing could blow on you at 70 MPH or something like that and then you are looking at big buck$"

My Mag side outer crankshaft bearing failed last Wednesday when my wife and I were 9 miles out on the trail[:(!]. Sort of made a slight squealing sound at the stop sign when crossing over the road and then the engine killed. I tried to start it with the starter and it clicked. I pulled the recoil and it was locked up so I removed the spark plugs and then it pulled over. I put the plugs back in and I then started it with the starter and it made a slight metalic rattling sound at first then mostly quieted down. Since I didn't have a tow rope for my wife to pull me back I drove it very slowly trying not to over rev the engine 9 miles back to my Cabin. Then loaded it my trailer and took it in to be looked at. Well I found out it was the outer Mag bearing. My sled has just over 7000 miles on it and the guy at the repair shop said that the crank bearings tend to go out after 5000 or 6000 miles so he said it was bound to happen sooner or latter at that milage. Well they called me today and said there is some good news even though I have over 7000 miles on it the cylinders walls and pistons are in great shape with no scoring and tested with in specs. He said that they only need a light hone and new pistons rings for the top end of the engine. I am also having both the Mag side bearings and the Pto bearings replaced. (one Pto bearing was a little growly when they spun it). He said the inner crank bearings spin real smoothly and I should be up and running by the weekend again. I am going to call them to put a fourth oil line and fitting in for the PTO bearings. Do I need an oil pump from 1997+ Xlt with the fourth line? Or can they use my old oil pump with a tee? I heard that this modification helps to make the PTO side crank bearings more reliable and should help me get another 7000 miles or so out of it. Funny[confused2] I was actually putting in some big miles this year. Its one the best snowmobiling years we have had in Minnesota for quite some time. I had just finished spending some bucks putting in my 133.5" 0.875" SKS track which I am enjoying very much. My wife says cool it on the toys.[Disappointed] I just put a set of Sly Dog composite skis on her 1996 Polaris 440 sport Touring 2up. It was time to replace the wear rods and the stock Metal Polaris skis sucked anyway so I said why not? Cheaper than a new sled I thought then my XLT took a dump on the trail.[:(] Oh Well its only money.[baldy] Just Remember "A snowmobilier and his money are soon parted".
 

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GustoGuy said:
"If you have a bearing that is failing don't run it and wait for it to grenade. Its better to have it fixed especially if the top end is still in good shape. The bearing could blow on you at 70 MPH or something like that and then you are looking at big buck$"

My Mag side outer crankshaft bearing failed last Wednesday when my wife and I were 9 miles out on the trail[:(!]. Sort of made a slight squealing sound at the stop sign when crossing over the road and then the engine killed. I tried to start it with the starter and it clicked. I pulled the recoil and it was locked up so I removed the spark plugs and then it pulled over. I put the plugs back in and I then started it with the starter and it made a slight metalic rattling sound at first then mostly quieted down. Since I didn't have a tow rope for my wife to pull me back I drove it very slowly trying not to over rev the engine 9 miles back to my Cabin. Then loaded it my trailer and took it in to be looked at. Well I found out it was the outer Mag bearing. My sled has just over 7000 miles on it and the guy at the repair shop said that the crank bearings tend to go out after 5000 or 6000 miles so he said it was bound to happen sooner or latter at that milage. Well they called me today and said there is some good news even though I have over 7000 miles on it the cylinders walls and pistons are in great shape with no scoring and tested with in specs. He said that they only need a light hone and new pistons rings for the top end of the engine. I am also having both the Mag side bearings and the Pto bearings replaced. (one Pto bearing was a little growly when they spun it). He said the inner crank bearings spin real smoothly and I should be up and running by the weekend again. I am going to call them to put a fourth oil line and fitting in for the PTO bearings. Do I need an oil pump from 1997+ Xlt with the fourth line? Or can they use my old oil pump with a tee? I heard that this modification helps to make the PTO side crank bearings more reliable and should help me get another 7000 miles or so out of it. Funny[confused2] I was actually putting in some big miles this year. Its one the best snowmobiling years we have had in Minnesota for quite some time. I had just finished spending some bucks putting in my 133.5" 0.875" SKS track which I am enjoying very much. My wife says cool it on the toys.[Disappointed] I just put a set of Sly Dog composite skis on her 1996 Polaris 440 sport Touring 2up. It was time to replace the wear rods and the stock Metal Polaris skis sucked anyway so I said why not? Cheaper than a new sled I thought then my XLT took a dump on the trail.[:(] Oh Well its only money.[baldy] Just Remember "A snowmobilier and his money are soon parted".


Hi,
New member here just joined
have interest in bying a used 96 XLT 500 long track xtra 12 2-up. been years since we have been into sledding, my boys are getting older and I want to get back in. this 96 im told has a bad MAG side seal curious if its worth fixing myself,
very mechanical on cars and Motorcycles have not done a sled block. looking for a little update on what to watch for since the last sled I had was a 93 500 indy. about 14 years ago had yamahas srvs, phasers, did chaincase, clutch,boggys, tracks and carbs thats about all they ever needed.
please let me know your thoughts, looks like you have a lot of experience with yours.
Thanks Shootskb (new member)
please let me know
 

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shootskb said:
GustoGuy said:
"If you have a bearing that is failing don't run it and wait for it to grenade. Its better to have it fixed especially if the top end is still in good shape. The bearing could blow on you at 70 MPH or something like that and then you are looking at big buck$"

My Mag side outer crankshaft bearing failed last Wednesday when my wife and I were 9 miles out on the trail[:(!]. Sort of made a slight squealing sound at the stop sign when crossing over the road and then the engine killed. I tried to start it with the starter and it clicked. I pulled the recoil and it was locked up so I removed the spark plugs and then it pulled over. I put the plugs back in and I then started it with the starter and it made a slight metalic rattling sound at first then mostly quieted down. Since I didn't have a tow rope for my wife to pull me back I drove it very slowly trying not to over rev the engine 9 miles back to my Cabin. Then loaded it my trailer and took it in to be looked at. Well I found out it was the outer Mag bearing. My sled has just over 7000 miles on it and the guy at the repair shop said that the crank bearings tend to go out after 5000 or 6000 miles so he said it was bound to happen sooner or latter at that milage. Well they called me today and said there is some good news even though I have over 7000 miles on it the cylinders walls and pistons are in great shape with no scoring and tested with in specs. He said that they only need a light hone and new pistons rings for the top end of the engine. I am also having both the Mag side bearings and the Pto bearings replaced. (one Pto bearing was a little growly when they spun it). He said the inner crank bearings spin real smoothly and I should be up and running by the weekend again. I am going to call them to put a fourth oil line and fitting in for the PTO bearings. Do I need an oil pump from 1997+ Xlt with the fourth line? Or can they use my old oil pump with a tee? I heard that this modification helps to make the PTO side crank bearings more reliable and should help me get another 7000 miles or so out of it. Funny[confused2] I was actually putting in some big miles this year. Its one the best snowmobiling years we have had in Minnesota for quite some time. I had just finished spending some bucks putting in my 133.5" 0.875" SKS track which I am enjoying very much. My wife says cool it on the toys.[Disappointed] I just put a set of Sly Dog composite skis on her 1996 Polaris 440 sport Touring 2up. It was time to replace the wear rods and the stock Metal Polaris skis sucked anyway so I said why not? Cheaper than a new sled I thought then my XLT took a dump on the trail.[:(] Oh Well its only money.[baldy] Just Remember "A snowmobilier and his money are soon parted".


Hi,
New member here just joined
have interest in bying a used 96 XLT 500 long track xtra 12 2-up. been years since we have been into sledding, my boys are getting older and I want to get back in. this 96 im told has a bad MAG side seal curious if its worth fixing myself,
very mechanical on cars and Motorcycles have not done a sled block. looking for a little update on what to watch for since the last sled I had was a 93 500 indy. about 14 years ago had yamahas srvs, phasers, did chaincase, clutch,boggys, tracks and carbs thats about all they ever needed.
please let me know your thoughts, looks like you have a lot of experience with yours.
Thanks Shootskb (new member)
please let me know
The 96 XLT is a 600, not a 500.

Other than that, if you're good with 4-stroke engines, and you've already been elbow deep in a 2-stroke, the XLT shouldn't be a problem.
 
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