2007 Blown Dragon Rebuild

[charlevoixboy]

Hey guys/gals! I'm new to the forum, and new to the polaris scene. This is my first "real" snowmobile, before this sled I rode an AC Z370 (for sale now) and some 70's AC sleds. I mostly stick to the dirt (03 CRF450R, and 83 Diesel CJ7) but decided to bite the bullet and get a sled too, since I live in northern mi and have a cabin in paradise mi, and should use that the other 4 months of the year.

I bought the Polaris off craigslist for $1500. It has approx 5500 miles, and "locked up" on the trail. Didn't burn down, just locked up. The engine would spin than catch at one point you cant spin past. I peaked down the plug holes and through the powervalves, and it looked like a lower end problem.

Other than the engine it was in really good shape. The body has a crack in the left side panel from a stump, but nothing is bent or twisted.

The only extras it has is an under the seat tunnel bag, and a dealer installed e-start kit. So maybe I'll have to sell the e-start to cover costs. We'll see.

Any opinions/questions are more than welcome! I'll continue to update!

-Grant from Charlevoix

 

[charlevoixboy]

After popping the pipe off, it was obvious that there was something really, really, bad going on in the lower end. Turns out the mag side rod bearing went, and took the case with it. I found the ENTIRE rod bearing in the bottom of the belly. The cases probably could be welded if I was a gambling man, and maybe that'll be a summer project (probably not!) I've seen cases like this welded up and run just to prove a point. I'd rather start with known good cases for this winter!

Found a lead on some cases from a 2007 CFI 600. Google says they're the same case, and the part #'s back that up (same #.) Below are some more pics of the tear-down

Anyone have a good used cylinder, powervalve covers, a lead on a rebuilt crank, or any other parts for cheap? haha

I'm also looking for the following if you have them kicking around and want to get rid of them: a good spare belt, a junk stock or aftermarket can, and nuts and bolts.

 

[charlevoixboy]

Got the bay all cleaned out, really need powervalve covers and springs. Ordered cases, crank will be ordered ASAP, along with all the rest of the parts.

 

[volcano buster]

Have you found anything that would indicate why the bottom end went out?

 

[charlevoixboy]

The mag side rod bearing completely disintegrated, jamming between the case and the crank. Literally there was NOTHING left of that bearing. I found the entire bearing in the bottom of the belly pan! It grenaded bad

I'm assuming it was just time for it to go, no indication of running lean

 

[charlevoixboy]

Really need to find a used cylinder for this thing. Just need the cylinder! Please help

 

[charlevoixboy]

Reman cylinder purchased, all new parts came except for the crank, which should be here Friday. Looking forward to putting this together!

 

[charlevoixboy]

Update:

Sled is running and moving! I have a problem though, after a few minutes of hard riding, the overflow will start spewing coolant out, and boil over. Thermostat is installed with the spring facing the engine. Coolant gauge shows like 130 when this is happening. I'm thinking the engine has an airlock somewhere. Is there any tricks to burp this engine? I was thinking of driving it up a snowbank and letting it idle, then shut off, crack the bleeder screw on the tstat housing, tighten and repeat. Any advice? Other than that everything runs great! Thanks in advance

 

[volcano buster]

Try the snowbank trick and then report back.

 

[charlevoixboy]

Head orings were the problem. Went for the polaris ones this time. The ones supplied in the SPI kit must have been made of natural rubber, and literally melted in the head. VERY dissatisfied. The mag side seal supplied in the kit was the wrong one also. Wasn't even close to fitting.