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  1. #1

    Pro 785 Crank index

    I did a crank index check today on my limited boat and from #1 to #2 I am 1 degrees out. #2 is coming up to quickly. I bought the boat which was supposed to be ready to go, after a few problems I got it running half way decent, but it was still lean up top. I found this odd and the high speed needles did nothing to help the lean condition. I jetted up then it was better but burnt a hole in #1 piston, the other two cylinders looked close but still lean. I'm guess this is my problem. Who should I use to fix the crank, or can they even be brought back into index. Should I just replace it? I know new cranks are big money. I'm just at a loss of where to go from here. I've had this POS three years and haven't gotten a decent WOT pull but once and it burned #1 piston down. I checked the index with a dial indicator with the head off, and i double checked it. I'm really at a loss of hope for this thing right now, I'm half temped to part it out and be done with it.


  2. #2
    SPEED KILLS, BUT YOU GET THERE QUICKER Keddano's Avatar
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    Unless it's a welded crank,it can be fixed.Some of the guys can recommend some of the good rebuilders they've used. You may want to get it welded to prevent any tweaking. Are you positive you don't have a fuel problem?

  3. #3
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by osswalam View Post
    ...from #1 to #2 I am 1 degrees out...
    Is one degree difference in crank index enough to cause trouble, even in a Pro785 engine?

    Could the ignition timing be off?

    Fuel pressure low?

  4. #4
    Rasta Mon Condoms We Be Jammin!!!!! TxVirageTx's Avatar
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    just one

    i wouldn't suspect 1 degree to cause that much of a problem.i'd check for water leaks in the pipes or no water at the stinger on that cylinder or a clogged seat screen in the carb,i'd suspect the fuel sytem first
    Last edited by TxVirageTx; 09-02-2008 at 09:41 AM.

  5. #5
    I'm sorry guys, it's 15 degrees out. The most allowed is 2 degrees either way. I'm definatly way out. Everything else has been checked, fuel pressure, timing, etc. etc. I've been through the whole boat. Pressure tested the pipes for the second time just this week, they all hold 10psi for as long as you want to watch the gauge. Everything is perfect and within spec except my crank. Anyone know a good place to have this rebuilt? I was gonna give Randy a call at Watcon, the previous owner said the crank may have been from him so I'll have to see if maybe he can help me out at all. Any input would be appreciated.
    Adam

  6. #6

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    Adam,
    what rpm's where you running at ??? and is this boat stock.
    Theres a guy in Wi. called Midwest Crankshafts his name is Jeff he did two 785 cranks for me this summer and i have had no problems with them .

  7. #7
    I have a limited boat that is a proven boat in the race circuit. It never turned the R's since I've gotten it. Unfortuntaly crank index is one of the few things i hadn't checked. I think I will contact midwest crank to see if they can help me out.

  8. #8
    SPEED KILLS, BUT YOU GET THERE QUICKER Keddano's Avatar
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    Quote Originally Posted by 785 lugs View Post
    Adam,
    what rpm's where you running at ??? and is this boat stock.
    Theres a guy in Wi. called Midwest Crankshafts his name is Jeff he did two 785 cranks for me this summer and i have had no problems with them .
    You can take LUGS advise to the bank.......
    Lugs is a greaat source for 785 info...........Abuse him.

  9. #9

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    I sent probably 15 cranks up to Midwest last summer from work. They always did a good job.

    I'd check with Randy at Watcon, Ronnie at Sharps, or Jeff at Midwest.

  10. #10
    www.springbreak-florida.com rgard32's Avatar
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    limited boat? whats in it? who built it.....just curious..

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