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Discussion Starter #1
burned up the piston on my sled last weekend and looking to replace that piston, any suggestions as far as if I should go with a wiseco or OEM?? Also was wondering what the main jets were from factory if anyone knows, once I tore it apart found out I had 240's for main jets and find it hard to believe that they came that way from factory. Supposedly the piston burned up due to lack of snow cooling the heat exchangers that are brilliantly located under the footrests, seems like a logical reason, just wondering if anyone else has had same encounter before or knows anything on the topic.
 

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There are also exchangers under the tunnel and at the front of the bulkhead. I highly doubt the motor burned down do to lack of snow, I have never heard of that being the single only reason for a meltdown. As far as the piston goes, try and find a good used one with low miles on it, that will save you a ton of money. Lots of guys are scared to do that but mechanically a piston is still a piston in the sled or out, just make sure your cylinder and piston your putting in are both in excellent cond. If you are deciding ONLY between OEM or wiseco? go OEM, if you put one wiseco in you should put three in.
 

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For the price of a new piston its not worth trying to verify mileage and wear on a used piston, remember the piston wears with its mating cylinder, so unless you can absolutely verify low mileage, and tolerances accuratley it might not be worth the headache. OE pistons are nice but pricey, check ebay though for good deals. One good alternative is SPX pistons, excellent bang for the buck, never had one fail, and know of many people that run them. You should definetly verify jetting, 240 sounds a little low unless this is the monoblock XLT triple, in which case it sounds ok. Check to see that maybe you didn't ice up a carb or something. Find the root cause before you go an replace the piston.
 

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Discussion Starter #4
it does have the monoblock. The dealer told me today that they came facotry with 260's for main jets. Well the story that I got from a fairly reliable polaris guy is that the reason it burned up was it it the farthest piston from the cooling system, and the snow last weekend was poor to fair, most places poor and we were definately running the sleds hard, so apparently the heat exchangers were not being properly cooled. The guy that told me this has also had this happen and another person he knows had it happen, but he also told me that I can replace just the one piston and it shouldnt matter if it is OEM or wiseco and also that the cylinder with the new piston should possibly be run with a 1-2 size bigger jet. Any other information or input is definately appreciated.
 

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Sounds to me like the "reliable Polaris Guy" smokes alot of weed. This is highly unlikely. If the cooling system was compromised in some way it would most likely affect the entire engine as it is a monoblock. What does the piston look like, post a pic, you will be able to tell right away what caused the loss. Sounds to me like you ran lean, maybe iced up a carb. If the sled has 240's in it should be ok as long as it wasn't super cold out, they always come jetted fat from the factory for safety.
 

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Discussion Starter #6
[attachment=55271]well the reliable polaris guy does know what hes talking about, I am 99% sure of that, he even told me what happened before I told him, including the temperature and snow situtaion. but I'm not one to argue and would like any kind of input on the situation at hand, anywhore, I am gonna try and post a few pics and see if it works, I dont think its possible to have iced up the carb as it was probably around 35 degrees that day but who knows, like I said just lookin for some input on what happened, and you never commented on the jetting for the new piston.[attachment=55269][attachment=55270]
 

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Discussion Starter #7
also had another question well maybe a couple questions, ummm since I have the motor apart I was thinking it might not be a bad idea to put new rings on the remaining two pistons, but the dealer wants $52 for one set so I kinda scrapped that idea, the sled only has 1711 miles on it so I dont really think the pistons should be too worn. next question is about a "break in" period once I put the new piston in, is there one and if so how many miles. and the last question is I seem to have quite a bit of bog off the start, the clutch engages at 4,000 and from 4 to 6 its a pretty big pooch but after 6 its pretty decent, anything I can do to get rid of that bog and get better response from the start?
 

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I rebuilt a 96 Triple this fall. They have 260 mains. This particular sled has 5000 miles with a near perfect piston wash. The pistons were still good with 120 compression but he wanted it freshened up.
D
 

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i am curious as to how the spx pistons work in that motor? could someone inform me of this. even if it was the reed motor.
but anyhow if it were to of overheated due to lack of snow, your idiot light should have been on way before. also would have probally stuck the piston before burning it down. i would start with the jetting. nless youre way above sea level, 240s sound way to low. i would change all of them not just the new one. and start from there and work back down. how many miles do YOU have on this sled? it definatley looks like a lean condition, highly unlikely the snow, were you burping antifreeze when it stopped?
 

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your polaris guy is smoking crack...i had a 96 xcr and burned 2 pistons up in it and none was due to lack of cooling..infact i ran the river at 90mph for 20 miles (slowed down for turnes) there it was mostly glare ice with a few patches of snow once in awhile and i NEVER had the temp light come on or burn down because of that...check your pto side crank seal, carb boot, fuel pump, carb etc before blaming it on the cooling system
 

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Discussion Starter #11
Actually earlier in the day I was "burping" antifreeze, not to sound like a dumb ass but I thought it was just because I had filled the resevoir up to the max line the day before and figured that i overfilled it, and since that was happening what does that tell me? and as of right now I have 1718 miles on the sled, I bought it from a guy at work who just got a divorce, said its been sitting in his shed not ran for two years, I paid $900 for it, brought it home took the carbs off and cleaned them drained all the fluids and refilled them and put some new spark plugs in it and called it good, is there something else I need to check? I.E. seals or gaskets or whatever?? This was only the second time out with the sled and I put 45 miles on the first time and had to call it a day due to my buddies class act $5000 ski-doo he had just bought and we put on about 60 miles this trip before mine burned up.any other questions or comments feel free to reply. Also no one has said anything about the bog on the start. cant seem to find an answer for that, and yet another probably stupid question but what does the "SP" stand for on the other 96-98 model XCR 600 stand for?
 

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well it coulda been from over filling, or it could be you actually were overheating from lack of snow, conditions ect. honestly i doubt it was due to lack of snow. any snow is usually enough. once its spinning its on the exchangers ect. if youre overheating and riding in snow, theres usually more to it. as far as your bog, find out what jets are in your carb, not just main, but pilots, slide, needle jets. etc. is this sled completely stock?
 

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Discussion Starter #13
sled is completely stock, only jets I am sure of are the mains and it has 240's in it and came with 260's stock, havent really dealt a lot with sleds in my life and the lack of snow or really wet snow and location of the heat exchangers as the source of my burn up only made sense to me as it was the farthers point from the cooling system, I may be a dumb ass but it made perfect sense to me, plus the guy/guys telling me this have won their share of oval races in thier day so I just believed what he was telling me, as he used to race the same model sled that I have, if hes wrong hes wrong, I can accept that. anywhore, my idiot light never came on I was wondering about that, if it was so hot why didnt my light come on? and I read a few posts from people who have had this happen or burned up one or several pistons but still dont tell me what the cause of the problem is, the sled is going back together on thursday and I would like to know if I need to check other things while I have it apart.
 

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Discussion Starter #14
also ordered some new carb boots for it since I have it apart, the ones that are on the sled now are cracked but dont appear to be cracked all the way through, and when I said I have 1718 miles on it I meant the sled has 1718 miles on it I only have around 100 on since I bought it.
 

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pistonburner:

Your break in period should be about 200 miles, run 500ml of oil in your first full tank of gas and vary the speeds for the 200 miles, that will get everything broken in good.
As for your bogging problem: I would point at the belt tension. If your belt is loose your sled will sleep of the line and get going once it is moving. Your belt should be tight enough to make a little squeal but not to the point where your sled it moving down the trail at an idle. That should wake'er up.
 

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i know 2 other ppl besides myself that owened 96 xcr 600's and everyone one of them had a bog off the line...sometimes you would have to flip on the choke for a second while giving it throttle to get it to recover
 

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These motors need to be rebuilt properly, read here for more info:

http://www.geocities.com/schmidt92/polaris_faq.html
 

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Discussion Starter #18
well for anyone that cares, shes all done. ONE new Wiseco piston, had I known the price I was gonna pay for gaskets at a dealer I could have done all 3 with wiseco pistons and gaskets for about $60 more, anywhore, its all done, runs like a top so far, takin it to eagle river WI next weekend to hit the trails, would have messed around a little more but the guy who was helpin me had to get one of his oval sleds ready for the WC in eagle river next week, if I had more time I would have taken pics of everything, not totally sold on the cooling theory yet, carbs were very disgusting to say the least, sure cooling may have had something to do with it but I dont really think anymore that it was the total cause of the burndown. Thanks to everyone who posted a comment for your help and suggestions or prior experience with a situation similar to this, I just joined the sight and am pretty pleased so far.Thanks again.
 

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Part of fixing correctly is diagnosing what caused the problem. If you cannot come to a conclusion, all
possibilities need to be eliminated. Doesn't sound like this was done.

If you were going to put a Wiseco in ,you should have done all 3. Now you have 1 forged piston and 2 cast pistons in it. I can say that your so called knowledgeable Polaris guy doesn't know anything about yout triple. There was a casting defect on the PTO side. The oil hole supplying the PTO bearing is smaller that the others and needs to be drilled out. Also on sleds that are older with low mileage and are not run for long periods of time, the crank seals dry rot. This causes air to leak through and
lean condition which will melt a piston. If you haven't already, spray starting fluid down by the PTO crank seal while the engine is running. If you hear any rpm gain the seal is shot.
Just the age of the sled would have me tearing it all down and going through everything.

Hate to sound like an ass, but I think you may have more problems in the near future which result in spending more money in the long run.

I live by the motto "do it right the first time".
 
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