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  1. #1

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    1998 Pro 785 Restoration

    I bought a 1998 Pro 785 as a project. Outside, the ski looks great, inside, things are not so good. It was purchased in Florida and then shipped up to Wisconsin. As you can see it's a nice looking ski on the outside. Buying this, I knew I was getting into a project, but this Pro 785 is definitely a case of "don't judge a book by its cover." I was told that things were alright with this engine and it was running, but the crankshaft was wrong, because it had the wrong rods and the front of the crankshaft wasn't lined up properly.



    I was told the cylinders and head were milled by group K. The tops of the cylinder look more like they were milled with a grinder in someone's garage. It's quite horrifying.

    You can see how bad it is, with the combustion chamber leaking into the water jacket. I'm still at the "assessing the damage" phase, but it looks like the plan now is it clean up these tops, install proper time-serts into the threads that are messed up, and find a thicker gasket, probably something custom from cometic.



    The guy who had this before really gave CrankWorks a hard time, he thought the end of the crank was wrong, so he manually adjusted the timing plate by adding his own holes and grinding away a large part of the flywheel case as well as some of the engine case. He moved the pick up so far to the side he had to remove one of the bolt holes for the front cover.



    Here you can see the mess I've been dealing with. The guy also managed to remove all the timing marks from the timing plate when adding his new holes. So fixing this has been a shot in the dark. I wasn't sure if the end of the crank really was messed up or if the guy is just making stuff up.

    We got it close by setting the crank to TDC, then measuring 12 degrees off of center of the flywheel and setting it there. It should be enough to get it able to run, albeit a little retarded, and adjusted properly when the engine is running.

    I finished up today by figuring out how the water lines were ran for the pipes. I was told it was done the "watcon" way, but looking at the Watcon way in the posts on greenhulk, this is not quite the watcon way.

    It appears they blocked off the first water outlet, than ran a single line to each manifold, then ran the start and end of the pipes on their own lines, splitting them off on the ends. I'll have to measure the tubing used and see if it fits the watcon diameters or not.

    But that's where I'm at for now. I have work to do on my Jeep and snowmobile tomorrow, but once I'm back to work I'll be working on this thing on the weekends and posting updates as time goes by as long as people care.

    I also really want to thank xlint89 for those parts. I'm using a lot of parts I didn't think I'd ever need, and without his help this boat would be going into storage and ending up a parts boat. But I have a very good chance of saving this pro from being chopped up and parted out.
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  2. #2
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Wow, poor thing!!! I'm sure others will agree but you need to completely tear that thing apart and go over EVERY...SINGLE...THING. You can't trust anything was done correctly with that sort of "redneck engineering" going on with the stator. Trust me, it will be less costly in the long run if you check over everything.


  3. #3
    Derwood98's Avatar
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    Fully agree with hyoctane23. Tear the whole thing down to see what you are really in for. It's expensive to do it once, but really expensive to do it twice. Learned that the hard way.

  4. #4

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    Definitely going through everything I can. The ride plate mounts have been completely cobbled together somehow, and there's a leak. The next step for the weekend after this one is to get some epoxy and some 3M 3500 and do it all properly.

    I'll get more pictures next time, my phone died last time. I usually take good care of my stuff and I've had the same phone for almost 5 years now lol. I'll do some before and after of this mess for the next stage.

    The guy I bought it from completely mis-diagnosed what was wrong with it, I can't trust a single thing other than his ability to put stickers on stuff.

    Worst part is is that he's been blaming Crankworks for this thing not running right the entire time, and the crank is one of the only things that looks good inside the engine.

    EDIT: I have not forgotten about this project. I thought this winter was going to be garbage and I'd spend time working on it. Instead we have lots of snow and I've been snowboarding and snowmobiling like crazy. Not enough time for it at the moment between snow and work. Once the snow is gone it's time to get it done.
    Last edited by sdlvx; 01-26-2019 at 05:20 PM.

  5. #5

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    I forgot about this thread. It is up and running, and it sounds very good. I haven't had it on the water yet but I ran it on the hose with my dad today and she sounds good. We managed to get the timing too. Today was a huge success!

    I should have updated this thread a little better, but here's some of the highlights from the build.



    The genius before me broke the barb off that the plastic cooling pipe that goes into the hull. So (my dad mostly to be honest) made this one out of aluminum. It fits very well, it's a little longer than the stock one. I think the stock one is not designed for a pump wedge and it has some play. This one fits very snugly with the pump wedge.

    I can't attach any more files. I'll post some more later, it's getting late. But this was quite the ordeal, with sleeves, boring, etc. All done with my dad. It was a great father son time and it turned out awesome.

    Thank you xlint again for the parts, there is no way I would have gotten this done if it weren't for you. You helped save a pro that was going to end up parted out and destroyed.
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  7. #6
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Thank you for taking the parts and saving another pro from destruction.

    Kudos on getting her running. Let us know how she does when you do manage to water test it.

  8. #7

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    So, this has been quite the adventure. The flywheel was lightened, the guy I bought it from said Watcon did it, but I don't even know. He said groupk did some work to the heads and jugs and they look nothing like other pics from groupk.

    Anyways, the rivets came loose on the flywheel, and the flywheel made contact with the stator. I ended up having to replace both. But now it runs fairly well. Thankfully nothing else was taken out along the way.

    Meanwhile, it still had an odd bog. The guy I bought it from explained it just as it was happening. Sometimes it would lose power trying to get on the pipes, sometimes you'd let off the pipe and it would bog. If you kept on it it would be ok for the most part.

    The duffus spent all this time blaming crankworks for the crank being wrong, changing timing, doing all this crazy stuff.

    I run it hard and chop the plugs, go in after backing all the screws out and notice the front is lighter than it should be and the center even worse. So, I figure there must be a clog in the carbs. I take them apart and clean them. The internal fuel filter for the mag was half filled with gunk. Center one was bad too, rear one was acceptable but barely.

    This guy spent all this time, he actually had the timing plate remachined so he could change the timing enough, when the carbs were what was wrong.

    This whole build has been crazy, I feel sorry for this boat being in the hands of someone like that. The front cylinder was a bit scored and damaged (had to sleeve it), after he put a new top end in. Besides him putting wrist pin clips in wrong, it sounds like he damaged a lot of the engine. He thought the timing was wrong, so he would have people hold it out of water to get it to rev up and get power, then drop it in and stay on the pipes to keep it running.

    I just have to put the carbs on today and fix some fuel line issues. Hopefully this fixes this poor thing.

    Oh, and as a bonus, I think he was messing with the electrical box, the ground in the ebox was loose. Glad I never have to see this guy again, he was getting close to totaling this thing.

  9. #8

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    Well, this is interesting. The plugs all look way better, nice and even. It runs better too. Until you make a left hand turn, even a slow one. Then it won't go past 4500rpm and won't really plane out, kind of like it's running on two cylinders. Once you free rev it it will run fine again until you turn. You might get away with making a turn if you keep it up in the 6000+rpm range.

    Besides the filters being clogged, the carbs looked decent. Needles and seats looked a little worn but that was about it. All cylinders are the same temp after this happens.

    I am perplexed. I'm scared this guy did something to the carbs and screwed them up. He loved to try and make this thing go faster when it wouldn't even run right.

    Usually I'm pretty good at searching but I haven't found much similar, other than people telling me to rotate the carbs 90 degrees.

  10. #9
    Click avatar for tech links/info K447's Avatar
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    How much might it cost to acquire a good used set of carbs?

  11. #10

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    I know I have a good pair on my other pro. I might just put those on the bad pro and see if it fixes it. If it does I'll know it's the carbs. Wish it was a little easier to do though.

    I only really had spare diaphragms in stock, maybe one of the check valves is bad, though I thought they seemed ok.

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