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  1. #11
    Myself's Avatar
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    Well, what I can tell you is that mag bearing is rust pitted all to hell. Probably water sat inside that engine at some point. The pitted lower rod bearing gave out just because of the rust pitting I would guess.


  2. #12
    sdlvx's Avatar
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    I see the rust now, I coated it with fogging oil after I got the top end off to make sure it didn't rust, but there was some on there. I am just wondering now if it's something I did or if it has to do with the previous owner messing up. I see the identical markings in the cases in the center cylinder, but I don't know if 15-25 hours is the right time frame for a rusty big end bearing to go out.

    I always fog it before winter and after every ride I mop up any water in the bottom of the hull and leave the seat off for a while. I'm usually pretty anal about this stuff, I'm surprised it happened but if this is something that only happens after a few hours of getting rust on the bearing I guess it would be my fault. Last year I put a good 15 hours or so on it, the crank was pretty fresh minus the PO running it in his own special way. I have no idea how long it sat before he gave up on it and sold it though. It was on PWCTarded for like a year at least. I really need to learn how to do cranks, it's the only thing I don't know how to do and it really annoys me. Plus everyone who does know how to do them is over 50 and that also bothers me.

  3. #13
    Myself's Avatar
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    No,....that pitting didn't happen in a few hours. Likely happened before you ever got it. Then, just running it was a ticking time bomb.

    I actually looked into doing cranks myself. The pressing and phasing is NOT rocket science, it's just basic machining and measuring. BUT, there are about $3k worth of special adapters and fittings to buy to do it properly.

  4. #14
    sdlvx's Avatar
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    This guy I bought this from really did ruin everything he touched with this machine. I can't think of much I haven't had to fix. But with the crank I am almost there.

  5. #15
    sdlvx's Avatar
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    Now that I think about it, it all makes sense. The guy putting the new crank in, giving me an extra head while the last one as milled (probably to remove all the chunks of crap from FOD), mark on the center crank case that looks exactly like the one in the front.

    He tried to do the watcon way of cooling, but he was too cheap to ever put the one way check valve feeding the front pipes. I think his lack of check valve let water run back into the engine and he had a problem with this. I put a valve on there as soon as I got it, but I think it was too late. I suppose you definitely need that check valve in there, not that I personally ever questioned it, but watcon cooling without a check valve seems to cause water to flow back into the engine.

  6. #16
    Connecticut CrazyA's Avatar
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    Those cases look shot. Can’t help but wonder if someone used mismatched cases or sanded/ground on them. That can tighten up/pinch the bearings and cause failure. It also looks like along with the “gold dust” that there is some rust. But regardless, those cases look to be toast. I’d start looking for a set.

  7. #17
    sdlvx's Avatar
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    Is there a difference between Pro 785 cases between years? 98 and 97 have different part numbers than 99 and later. But I got bit by this before with my small end crank pushing.

  8. #18
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Quote Originally Posted by sdlvx View Post
    Is there a difference between Pro 785 cases between years? 98 and 97 have different part numbers than 99 and later. But I got bit by this before with my small end crank pushing.

    Believe the difference is the later 98+ had the reed spacers built in. The '97 and early '98s had the separate reed spacers.

  9. #19
    so just to add to what everyone else has already said .... the cases are junk, looks like someone used a rat tail file on them. It will never hold a bearing correctly and you can see the bearing chatter both on the cases and the bearings from a loose fit. The crank has clearly had water in it,(doesn't take much water to rust up bearing especially if that rod was down with just a bit of water in it for a short time. I have pulled numerous snow cranks apart that the rods felt good but the needles were already getting ground down getting ready to fail, and this was just due to moisture and not fogging them.some guys never fog them and get away with it .... some guys pay the price ) I see there is no lock pin on the bearing on left side of rod but possibly has one on the mag end? are you even sure this is a crank that crank works did... doesn't look like anything they would put together in my opinion as Hyoctane said. these guys are really good at cranks.

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  11. #20
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Sorry, I got nothing more to add.

    Just wanted to say hello to Art and Rich. Good to see you guys.

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