Polaris PRO785 with wrong rod length. Want do ditch this thing (St Petersburg FL)
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  1. #1
    PWCToday Regular
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    Polaris PRO785 with wrong rod length. Want do ditch this thing (St Petersburg FL)

    Here is the deal with this thing: I sent the PRO785 crankshaft to Crankworks in Arizona along with a 780 crank for spare parts. I sent brand new SBT rods, OEM bearings, and new crankpins with it. I got it back and assembled the entire engine. I tested the compression and it was not right. I checked the stroke and it was wrong. I had to take the engine out and send the crank back to Crankworks because they had rebuilt the wrong crank and they threw out my 785 crank. They agreed to re-stroke the crank for free and they sent it back to me. I again assembled the engine and the compression was better. But still not high enough considering I had the head milled down by Group K. I called crankworks again and they said they never measured the rod length because the tech had thrown out my original 785 rods and they had nothing to compare to. Now the engine is assembled and in the ski again and it starts and runs but bogs at low rpm and loads up with fuel. That is because the rod length is incorrect and the pistons pass the ports at the wrong time. What this thing needs is a set of OEM PRO785 rods. The flywheel key is also clocked about 30 degrees out of place due to them using the wrong end but I was able to move the stator and re-drill the mounting holes in the stator plate which allowed me to set the timing perfectly. I am OUT OF TIME and patience to take this apart and do the rods. I have spent THOUSANDS and will take a disgusting loss on a ski that could be worth a lot if I could finish it. My loss is YOUR GAIN. I'll sell it for $999 first come first serve

    Here are the rest of the details about what I have done to this ski:
    Freshly rebuilt motor, crankworks crank, Group K head with wide squish bands, new wiseco pistons, brand new re-plated
    stock bore cylinders, port and polish on cylinders and exhaust manifolds with matched gaskets, rebuilt carbs, watcon
    lightened and balanced flywheel, watcom cooling mods with special diameter hoses and billet flow control valve, brand new
    starter, top loader, intake grate, new solas X prop, new hull seal and shaft coupler on engine, 4" bar risers, billet throttle,
    protaper bars, good hull, no leaks, no fiberglass repairs, no deep scratches, cracks, or damage. Clean title in my name. Does not
    include trailer.
    Located in St Petersburg FL 33713. Text 248-878-6386
    Attached Images Attached Images

  2. #2
    PWCToday Guru Dan87951's Avatar
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    Re: Polaris PRO785 with wrong rod length. Want do ditch this thing (St Petersburg FL)

    Sorry to hear! After reading your post, I will never use Crankworks out of AZ! It's unbelievable the level of incompetence they displayed when they "rebuilt" your crank. Yikes! I wonder how many others sent their crank to them and could never figure out why their ski ran like crap?! I have heard SBT makes rods for the 785, but haven't used them. Maybe it's a cheaper option if you decide to rebuild, again. Ugh. Good luck!
    04' Shorelander Double Trailer
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    96' Sea Doo XP - Garage Queen
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    95' Sea Doo XP800 #2 - Was a project, now fully restored and providing lots of smiles.
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  3. #3
    PWCToday Regular
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    Re: Polaris PRO785 with wrong rod length. Want do ditch this thing (St Petersburg FL)

    Yeah, the rods I sent them were SBT rods. I think there may have been a period of time where SBT had those listed as 785 rods but they were actually 780 rods and won't work on the 785. If crankworks hand't scrapped my crank, they would have still had the rods. And if you use the logic that I might be doing a stroker crank, the rods would need to be longer. Jet these were shorter causing decreased compression. So it proves that they didn't even hold the rods up to eachother to compare them. If you are paying a crank expert to do a job you could do yourself, you are paying them to do stuff like that and pay attention to detail. Man what a nightmare. I lost my *** on that ski but finally got rid of it.

    Quote Originally Posted by Dan87951 View Post
    Sorry to hear! After reading your post, I will never use Crankworks out of AZ! It's unbelievable the level of incompetence they displayed when they "rebuilt" your crank. Yikes! I wonder how many others sent their crank to them and could never figure out why their ski ran like crap?! I have heard SBT makes rods for the 785, but haven't used them. Maybe it's a cheaper option if you decide to rebuild, again. Ugh. Good luck!

  4. #4
    Frequent Poster
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    Re: Polaris PRO785 with wrong rod length. Want do ditch this thing (St Petersburg FL)

    I have this ski, it runs good.
    90 Superjet - Coffman pipe, other mods
    98 Polaris Pro 785 - stock graphics, just ported and polished
    98 Polaris Pro 785 - black top, cylinders milled .020, ported, polished, watcon cooling
    95 Kawasaki 750 sxi - R&D pipe, ported, polished, bored 1.5mm over
    01 Polaris 600 sc xp sled - Stock

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