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    Mercury 850 Thunderbolt (85hp) What is the correct Lower Unit for this model?

    Here's my problem! My 85hp merc inline 4, I think is a 1977 according to the ser. # 4846571<br />The lower unit is history. I got another used lower from a marine mechanic. Now here is the dilema: this driveshaft on the used lower has the preload pin on the top of the shaft, the mechanic said it...
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    Lower Unit Swap Merc. 850 using 65hp lower

    Here's my problem! My 85hp merc inline 4, I think is a 1977 according to the ser. # 4846571<br />The lower unit is history I believe it blew a forward gear (reverse still worked) SO instead of spending over $1100 CND. for new parts alone I was able to buy a used lower from a marine mechanic that...
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    Mercury 850 (1975-85hp) ser#4846571

    HI, I'm looking for an assembly dwg. of the lower unit for this motor! any out there?<br />Also the reason I took it off: It would not go into Drive w/o grinding and clunking shaking the motor violently, worked OK in reverse tried adjusting the shifter cable @ the engine now it did it in fwd. &...
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    85hp Mercury ThunderBolt Gear Engaging problem

    Help My motor just started shaking violently when I put the motor in FORWARD and reverse! It Started out doing this just in forward so I adjusted the gear selector cable @ the motor (moved the brass turnbuckle closer to the cable end) thinking this would pull it into drive more it just got...
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    Mercury 85hp O/B '77? Blue Band-Checking lower Unit gear Oil

    Hey I'm new to this boating thing! I bought this 16' Tri-hull Bowrider w/this motor on it. Was working great till a few days ago go to put it in drive , clunks and shakes? will run fine in reverse. I think its cables I tightened up the brass adjuster on the drive cable so the pull in too...
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    1977? Mercury 850-85hp

    Having a drive problem! It will run smooth in reverse but when I go to engage drive it revs way up before going into gear then makes a huge clunk when its in drive. Which doesn't happen until nearly @ the end of the lever limit. and clunks back and forth shaking the transom! Is this the gear...
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    4s2wwr

    I have a '77-'80? Thundercraft Bowrider Trihull that I came home to find submerged in 2 feet of water @ the end of my dock. I had it out for 2 days before that no obvious leaks before this. Bilge area was dry? How can I now find the leak? it's out of the water and on my trailer. There is a...
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    '76? Mercury 85hp o/b Lower Unit Problems

    Had the boat in the water for about 2 weeks worked great! (16' ThunderCraft Bowrider)Tubing and cruising etc. Has power tilt & trim. Now when I go to put it in Forward it revs up and makes a huge clunking sound shaking the transom back and forth. It will work in reverse! Any quick Ideas what...
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