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  1. #41
    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by sdlvx View Post
    ... cast iron (I think that's what the head pipes are) ...
    Confirm what metals the pipes are actually made with.

  2. #42
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Head pipes and the actual pipes are aluminum. Do NOT use muriatic acid to clean those. I had a head pipe clog up before and I tried vinegar as well but had no luck. I had to get a new head pipe and all was good after that.


  3. #43
    I'D RATHER SWEAT THAN SHIVER hyoctane23's Avatar
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    Quote Originally Posted by sdlvx View Post
    I was thinking there's something wrong with how the guy ran the water lines, and was going to just pull some of the pipes and pressure test while I was at it.

    I've been searching but I couldn't find much, all I need to do to pressure test is plug the water jacket, except for one inlet, and then pump it up and see if it leaks, right?



    That's what he happened to do. And he used some crappy plastic fittings. I think the back of the pipes aren't getting enough water and something is broken and slightly leaking. I feel like if I get the top pipe off I can get to everything else a lot better. I cleaned up a lot of his retardation but I guess not enough of it.

    Head seems to be a very good temp. I did clean the water manifold out before putting it back together. But I feel like I screwed up pretty bad leaving the cooling like this.

    I'm going to go tear into it, wish me luck.

    EDIT: There's a 3/8th hose running to the back of the pipes, then it splits into three 1/8ths hose
    Could you post a picture of how this is routed in your boat?

  4. #44

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    Quote Originally Posted by hyoctane23 View Post
    Head pipes and the actual pipes are aluminum. Do NOT use muriatic acid to clean those. I had a head pipe clog up before and I tried vinegar as well but had no luck. I had to get a new head pipe and all was good after that.
    That's what I thought. I had some luck before with vinegar, but it had to sit for a while soaking. I think it depends on what's clogging it. I already have them off and tried blowing through them. The problematic pipe seems like there's something wedged in there, sometimes restricting and sometimes. First blow was not easy, then it blew fine. There is probably sand and salt in these things, vinegar should work on that. I think there's something in there that is moving around and occasionally restricting things, which matches up with my symptoms of it running great then suddenly having problems.

    Quote Originally Posted by hyoctane23 View Post
    Could you post a picture of how this is routed in your boat?
    I already did it the proper way, I have nothing to take pictures of. But basically, instead of running three separate lines to the base of each pipe, he ran one line and then split it with a bunch of plastic fittings. He then took another port from the manifold and ran it to the .09 restricted line.

    This means he had a line running off the water manifold going to each head pipe, one line that split that went to the back of the pipes, then another line that ran to the front of the pipes. Everything else was done the watcon way per the drawings.

    I thought that maybe the one line feeding all the pipes instead of three was causing not enough water flow but that was very optimistic.

  5. #45

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    I pulled out the micrometer. All these 1/4in hose fittings this guy before me put on everything don't actually measure .25 inches. They are more like .15in if they fit 1/4 in hose. I got some proper ones, this would explain a lot. I think the pipes weren't getting enough water, but enough was getting to the head to keep it cool.

    I noticed when flushing my head pipes out that they need a good amount of pressure and volume to fill up all the channels, otherwise the water just flows along the bottom even if the sides aren't clogged.

    Not to mention there is no water jacket on the top of the head pipe, which makes sense that would be the hottest part.

    Yesterday I took out my other pro and did some splash tests, I had the same result that there was a little sizzle (no steam) when splashing the top of the head pipe where it mounts to the engine, the first time you splash. Then it goes away. I either have two messed up pros or that's how they're supposed to be. I have had an overheated ski before and it wasn't sizzling like that.

    I should have checked this stuff earlier.

  6. #46

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    all the water lines should be 3/8 hose not 1/4

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  8. #47

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    Quote Originally Posted by 785 lugs View Post
    all the water lines should be 3/8 hose not 1/4
    It is now. The guy actually ran quarter inch hose off the cooling manifold, but he couldn't get the 1/4in lines onto the head pipes so he left the 3/8th hose there and used a plastic adapter to convert from 1/4in to 3/8in hose. And the inside of the adapter was massively restrictive, .15in according to my trusty harbor freight micrometer.

    I set it up proper, I have a spare cooling manifold and measured the stock outlets to the heads, they're all .25in except for the head pipe which is .27in. So I put those on.

    I work weekends but this afternoon I will hit it and see what happens. I think that should fix it.

    What a mess this thing was, I had to go through EVERYTHING. Even the ground in the electrical box was coming loose. The machine was a total mess. All these problems with this ski, and the previous owner was obsessed with Crankworks screwing up his crank and the crank being the sole reason it won't run right.

  9. #48
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Was there extra head pipes in the parts you picked up? I thought there might be.

    Yep, the sole reason we recommend new owners go through EVERYTHING when they buy a used ski. You're living proof of the stupid stuff people do to these things.

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  11. #49

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    Quote Originally Posted by xlint89 View Post
    Was there extra head pipes in the parts you picked up? I thought there might be.

    Yep, the sole reason we recommend new owners go through EVERYTHING when they buy a used ski. You're living proof of the stupid stuff people do to these things.
    Oh yeah, those brass fittings that have the proper restrictors are not something you find at the hardware store. I stole a lot of fittings off of the stuff you gave me, saved me yet again (thank you). Some of them looked a little crusty so I'm letting them soak, I'll need them soon or a later. I got the other ones flowing fine, and they were polished and all cleaned up, port matched, etc.

    I got out for about 30 minutes today on it, it runs awesome. I think it's loading up when I back off the throttle though, kind of hesitates/bogs after a long idle or stopping the engine. It works itself out of it and runs 100% after that though.

    I set popoff around 18psi, just used a bike tire pump though, not sure how accurate. Probably needs some more. I also backed the high speed screw out an entire turn, because the cylinders were milled, it's been ported and polished, and the choke kit is replaced with a primer.

    Other than that it ran like a champ. Almost feels like it's running quite a bit better than my other pro. Feels good to finally get this thing running right and to rescue it from the clutches of that dipsh*t.

    I've been chipping away at it for so long, and today it's finished. I got done and didn't know what to do with myself, ended up washing my jeep and fixing some of the faded plastic, lol.

    It's much louder than my other pro too. I'm assuming it's because there's less water in the collector and waterbox. Same thing happened when I dried out the box on my superjet. But that's just one coffman pipe on a 650 and three factory pipes on a 785 probably adds a lot more.

    Feels so good to have it running, thank you everyone for all your help and suggestions. This ski was so messed up pretty much everyone in the thread who suggested something was wrong was right.

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