My First 2-Stroke Crankshaft Rebuild...Much Cringe

[TheDullCarbide]

I have a 1980 Ski-Doo Everest L/C Electro 464 snowmobile. Last season, I...well...the oil injection pump...toasted the crank pin bearing on the magneto side connecting rod. Lets play a little game of spot the difference:





Now that first picture, the PTO side, seemed okay, right? I know this engine was rebuilt before because the connecting rods were facing the wrong way! Both of them!!! The lubrication slot that you looked through should be facing the other way according to the manual, since there is only one slot in each rod. I don't have to worry about this when I put it together because my new rods come with two slots, one on each side. That still doesn't change the fact that I must still take apart the good side because of that slot.

The first question to you is: "How do I press that crank pin out of the outer web?". Or more importantly: "Can that thin web take a 10 ton press?" and "What tool do I need to make?". This is the tool I have made so far. It doesn't work for :001_9898::







As for the tool I have to make, if the thin part of the webs can't take the force, there's three different depths in that web I would need to cover plus some raised numbers that would make a pressure point:



And...last question...for now? How in the hell am I gonna pull this one off?:

 

[maverick1]

I was on YouTube a while ago and did find some video's on rebuilding 2 stroke cranks. Pretty sure they were using a press.

 

[Havasu Dave]

Here's a PDF on a service manual from 82. I didn't dig far enough in to it to see removal. There are specifications for gap on reinstallation. Vintage Snow has many PDF manuals on line. The Vintage Sleds forum would be where I would ask, instead of a mini bike forum which specialized in Chinese Lawn Mower Engines now. :shrug:

http://www.vintagesnow.com/Ski-Doo_files/1982_SM.pdf

 

[ole4]

I used to rebuild a lot of two stroke kart cranks. Here is the tool to press them apart I made. It was very easy using a 20 ton hydraulic press. Pressing them back together is a bit more tricky as the press flexes a bit and it is hard to control the amount of travel so you need to make something to fit inside the halves when pressing it together. I have seen people use an arbor press for assembly as they do not flex.
Here is the tool I made for disassembly. I only had a half crank to show but the other half would be inside the round pipe and the foam underneath is to cushon the crank half when it fell. the rod sticks out the opening on the side of the pipe.

I used to have a assembly jig for cranks which had knife edge rollers and two indicators which read in ten thousandths to tru the cranks using a lead hammer to whack them into alignment.

 

[TheDullCarbide]

Here's a PDF on a service manual from 82. I didn't dig far enough in to it to see removal. There are specifications for gap on reinstallation. Vintage Snow has many PDF manuals on line. The Vintage Sleds forum would be where I would ask, instead of a mini bike forum which specialized in Chinese Lawn Mower Engines now. :shrug:

http://www.vintagesnow.com/Ski-Doo_files/1982_SM.pdf

I have the 1980 version of that manual. I shows just about everything you can do with the crankshaft except replacing a conrod. I guess that job was meant for a Bombardier mechanic in the 80s. I know I should have joined a snowmobile forum, but I had to give this one a try. Either way, your advice is worth more than what I got.

 

[TheDullCarbide]

Okay, I'm giving up.:surrender: I'll let a snowmobile shop rebuild it for me. I'm screwed from the start being my hydraulic press bed is only 3 3/4" wide and my crank webs are 4".:censure: I'm just worried if they screw something up. I know they're trained and they do this for a living...but ehhh...I can't afford to have this crank damaged.

Does anybody know a good place to get this rebuilt?