Hey man,
Thanks for the reply. We were able to break down the motor again last evening and the piston had a small piece of chard metal laying on top. The cylinder has a small crack internally (looks like a stress crack from a bad casting in the water jacket) on the wall adjacent to the reeds. Also, the engine is still frozen with the piston removed from the cylinder. It actually slid right out - no problems and the rings are in good shape. The piston does have a small nick both in the front and rear exactly adjacent to each other on the very top so we'll replace that again. We removed both the clutch cover as well as the pull start and still can't budge the darn thing and can't figure out what is stuck. The crank shaft is frozen ??? Don't know if the transmission has some stuck/fused plates or what. Doesn't seem logical that the crank is bent. All oils were topped off to spec such as the counter balance etc. before we started the thing up. We're still going to check the oil pump when we get it running again because after 20 minutes of riding at 10 mph and lots of smoke/mist - the plug was clear and wet when removed.

Another thought -
The Polaris dealership had taken the lower housing off the machine last week to drill/easyout a drain screw that had been overtightened and broke off in the lower casing while we were working on the upper cylinder and piston. Perhaps they didn't reassemble the thing correctly. Any suggestions would be helpful and thanks again. We're probably going to bite the bullet and return it to the dealer but if we get some helpful hints we'll save his newspaper money for other things. [img]i/expressions/face-icon-small-smile.gif[/img]

Thanks again

 

I'm no engine expert but I think this makes sense.

I read your first post and didn't notice anything about coating your new parts in some 2-stroke oil before you bolted them in. With out the oil excessive heat would be built up while running the engine for its first few minutes and could cause it so sieze.

Another this is that you should have run it as rich as possible while breaking it in. You knew before you started the bike that the pipe had leaned out your mixture so why face losing another piston because of a cheap main jet and/or pilot jet.

 

Yeah thanks,

We did coat all parts with oil before assenbly. As stated, the problem isn't now with the piston frozen to the wall of the cylinder, the crank will not turn or budge an inch. The piston job went well except that we found a small metal shard on the top after inspection last evening. The piston has two small pits now on both the front and rear top and are exactly opposite each other. The arrow on the piston looking down on the piston from the front of the machine is pointing to the left or the pull start side. We just can't figure out what is binding the crank or otherwise.

 

It sounds like a main bearing is bad. The piece of metal on the piston is likely a piece of the cage that retains the ball bearings. I believe that you will have to split the case and repair the crankshaft. It isn't that bad of a job. But you need a few special pullers. You will have to deciede if you are up to the task. Good Luck.

 

If you feel up to pulling the engine yourself, a place called Northern Crankshaft in Thief River Falls,MN is a great price and great quality rebuilding facility. With the jug and piston off, I think they'll open the case, freshen everything up for somewhere around $250. You can do a search for their site. Like Scotty said, you've got something wrong in the bottom end. You might want your dear to re-install the motor, because lining up the clutches might be a little frustrating. Someone also said, richen that sucker up, don't risk burnin' it down again.


Ken

 

Pulling the motor isn't hard at all. I did mine in a couple of hours with the wifes help. Take it slowand remember where everything goes. When you split the cases go ahead and put new everything in there. I know it will cost a FEW bucks more but no telling what that metal did to the bearings. Get the numbers offof you bearings and go buy them youself and a bearing supply house. I went ahead and got a Wiseco rod when I did mine. Cannot remember the number but Dennis Kirk carries the rods. If you want the number I can get it for you. Getting the parts yourself will save a ton of money instead of getting them through Polaris. One bearing that is tapered is a Polaris part only or so I was told. Also buy the gasket and seal kits yourself. Dennis Kirk also sells those. Keep us posted on the progress and if you need numbers for parts through Dennis Kirk Iwill look them up.

Ronnie

 

Thanks so much to everyone. I'll print all these great tips - show my son, and let him make the decision. I'll update you next week.

Thanks again.

 

Go to partland.com. It will show you the details for each engine part and also has a place that you can order all the bearings from them. They are a little cheaper and it comes from them direct.

 

I'm sorry partsland.com

 

Please do some shopping around. HPD, Hot Seat, and Dennis Kirk are all within 45 mins of my house. Kirk's is ALWAYS more ching, unless you're getting something from the scratch and dent store. Also, HPD has a lot of testing on these motors, and has found the STOCK rod to be the better of the two. I don't remember exactly the words, but something about lighter, weaker, and more prone to vibrations.

I only suggest you send the motor out because the counter-balancer puller, and the spanner socket special tools really make things easier. I'm not saying you can't adapt something to the task. It just might be a little less stressful. Just my 2c.


Ken