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  1. #1

    Sink it? Or keep going?

    Hello All,

    Been doing a restore on a '94 SL650. Really looked in nice shape for it's age. Never saw salt water, was pretty darn clean, and got it from my boss for $500 with a nice trailer. ($25/week seemingly forever)

    I got it to start with a mustard bottle full of premix, and a lawnmower battery, before I bought it. It ran well enough, but didn't want to over run it out of the water and I didn't really know at the time what to look for. (dumb-*ss) So I started my project ...

    After doing all the suggestions and upgrades suggested for this ski, which had been sitting for 9 years inside under a tarp. $300 more later, I got it running well enough to ride it up and down the intercoastal once before it got hard to start. I had all the usual problems with fuel lines and such, (including a puddle of black rubber at the bottom of the fuel cell) I had to rebuild the impeller drive bearings etc. The only shortcut I took was to rebuild the original fuel pump instead of going new and sure enough, I wasn't getting enough fuel. I went ahead and put the new Mikuni Triple Out on it this morning.


    As I was cranking the engine with the new fuel pump this morning, I was very impressed with the amount of fuel I saw running thru my new inline filter and waiting for it to fire with optimistic entheusiam. While I was cranking however, something caught my eye down at the base of the PTO cylinder wall between the cylinder and the carb rack. I noticed a small line fluid pulsing around the base of the cylinder wall. Upon closer inspection, I have now found a hair-line fracture running low, around the cylinder wall, just above the lower bolt flange. It's running about 1/3 around the base facing the carb. Obviously, it must be all the way through or the oil and condensation would not be pulsating as I turn it over. WOW ! Imagine my mood-swing !! what a freaking drag. The only reason I got this darn thing was because I thought I could restore it fairly inexpensively if I did my own work. I am now up to about $800 invested and found this.

    You know, upon retrospect, I remember now seeing a whisp of smoke down in that area when accelerating during the initial start-up, but I foolishly wrote it off as probably coming from the bottom of the carbs or intake somewhere, or maybe just oil and dirt evaporating off the block. Whatever I thought it was, It never even crossed my mind that the cylinder could be cracked down there, and it wasn't clean enough then to see the clear line of oil-fluid pulsing at the almost invisible hair line crack like I have now found.

    At any rate, the girfriend is getting pissed at how much I'm spending on this thing and still not in the water, and now this. Does anyone know, if I remove this cylinder assy, can I weld over this crack with any chance of success? Is it even weld-able material? or is it just come sort of cast or pot-metal?

    If not, can I hopefully find a relatively inexpensive used cylinder and just slide it down over the original piston, with the engine in place, with any success. At least I can get the PTO cylinder off fairly easily.

    I appreciate you reading all my whining here, and any and all suggestions are also appreciated, and welcomed.

    And I sure hope this finds you all happier than I am right now.

    Take care,

    Jeff Galloway

  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Cleveland OH
    Jeff, sorry to hear about your experience thus far. That sucks.

    I'd be interested in seeing a pic of this crack you spoke of. Especially since most of the cyl is is water jacketed, and you say you can see oil coming out of it.

    To answer your Q, I wouldn't even consider welding it. Not worth it IMO. You can get another piston cyl combo relatively cheap for a 650. I would just replace them.

    Not to sound like a d!ck, but had you done a leak down test, you would have found a crack like that pretty quickly.

    I remember reading recently about another member that's had 2 Polaris skis come through his place that had broken PTO cyls. If your ski was running, and that crack was ignored, I'd be willing to bet that cyl would have broken. Very interesting........

  3. #3
    Hey xlint89

    Thanks for your reply. I've calmed down, and quit boo-hoo-ing since my post. I wrote it right after my discovery. Yeah, that's a drag .......... and you weren't being a d*ck, just stating the obvious. I admit, I just was way out of my areas of expertise when I was looking it over. Definitely not a Water-Craft person yet.

    I'm thinking about going back to the boss and asking him for a refund. I had told him that if I found anything catastrophic, I'd be asking him for a refund. I just wish I had known more how to do "Pre-Purchase" testing as you pointed out, or at least discovered it before I spent the time and money I have in it. I can't ask him to refund that, only the original $500.

    I'm also considering just keeping it and parting the darn thing out. I've certainly done enough shopping for the parts I bought so far to see that there's a lot of money in used Polaris parts. Between that and the trailer sale, I might at least break even?

    Having said all that though, I'm sure I'll look for at least a little bit to try to find a cheap Cylinder. I took the manifold bolts out, and the cylinder nuts off, and have been trying to wiggle the cylinder back and forth enough (without beaking other stuff) to get it to slide straight up. If I can, I'd consider just getting a new jug, put my head back on it, compress the rings, and try to slide it on. You think that could work?

    At any rate, thanks for the read, and take care,


  4. #4
    WFO 4 LIFE nitrosportman's Avatar
    Join Date
    May 2011
    Temple, TX
    so the actual jug is cracked? may just be a bad gasket leeting some blow through either way pull that jug off and don't half ass it go ahead and pull the exhaust manifold too to make it easier

  5. #5
    Banned User
    Join Date
    Jun 2010
    Milwaukee WI
    If you get a new cylinder, I would suggest honing the cylinder and installing new piston rings. Your existing rings are seated to your existing cylinder. Changing that may cause loss of compression. I think a set of new rings is around 20 bucks for the WSM's. You are into it this far, I wouldn't think another hundred bucks or so would be enough to kill it. Besides, parting out a 650 may not work out that well. I don't think there is a huge demand for 650 parts, and they tend to not get as high of a price as parts for other skis, at least from what I have seen.

    Something like this would get you going.

    That way you already have a piston matched to the cylinder. Get yourself a top end gasket kit and you will be good to go.

  6. #6
    need agood used piston and cylinder cheap?

  7. #7
    castiacsportsgagrage, yes, how cheap? It will be a while before I have another $100 for this thing. Hoping for more like $50 including shipping.

    nitrosportsmen ........ yup, the actual jug is cracked down below the jacket areas, darn near 1/2 way around it. I'll post a pic when I get it off. I'm still gonna try to half-ass it though, There's a huge ?metal piece? blocking access to the forward Mag manifold bolts ........... Thanks for reading, and read on below for a real laugh !!

    BryanP, thanks for posting that e-bay picture of that cylinder & piston ......... guess what, my dumb *ss was trying to pry that jug up between the manifold and carb rack and I was so frustrated about the whole thing that I didn't do any research. I just started taking bolts out, hoping for the best, and I didn't even realize there was a third (bottom) bolt holding the manifold to the jug. I'll take that off, and as much as I had it moving even with that 3rd bolt in it, I'll bet it will slide right up now. I probably never would have seen it until I broken the middle cylinder trying to pry against it to release that darned PTO jug.

    So again ..........thanks !! ........ and I'll slow down and study this a bit harder before I get back to it. It was so freaking hot and humid out this morning, and I was so disappointed in what I'd discovered, that I decided I'd better walk away from it for the day ........ before I took a flame thrower to the whole thing !!

  8. #8
    Well, Imagine that !! Took off the 3rd manifold bolt that I couldn't see, removed the carb rack for more room, and voila, the jug slid right up and off the piston with no problem. Even the exhaust gasket and jug gasket are reusable. Now all I need is more $$.

    Oh well, it could have been much worse ...... it could have been the Mag jug.

    All that rocking I did with the 3rd manifold bolt still on really made the crack go all the way around it though. Not like it was salvagable though. Upon inspection, it looks as though I was just seeing air coming out of the crack. There must have simply been enough oil and condensation built up there to make me think it was actually coming out of the crack. When actually it was just being pulsed by the air passing thru it.

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