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    Engine continues to turn over after ignition is shut off

    I have a 1978 mercruiser 470. I hooked the battery back up to it after it set over winter and tried giving it a start. The motor cranked slowly, as if battery needed to be charged (it has set all winter). I turned it over for about 6 seconds, then released the key. The motor continued to...
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    mercruiser 470 runs good.....for awhile :(

    My boats motor is plagued by the same problem as last year...its a 1978 470 and EVERY time i load it in the water it fires RIGHT up beautifully. Then I take it out and after a hour or so it loses power and wont go above 1500rpm. Did dons fuel test and its good? any advice....can a stator cause it
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    mercruiser outdrive swap...will it work?

    Hello all. I have a 1978 mercruiser outdrive thats on a mercruiser 470 motor. I believe this makes it a pre-alpha outdrive(if Im wrong let me know). The top of the out drive has a "eyehole" on the top of the cap as opposed to being flat if that helps you picture it. My lower unit had...
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    wont shift: coupler?

    my 70 pre alpha outdrive worked fine...stopped on the river to switch drivers so I could ski and then all the sudden it wouldnt go into gear for him. Foward nor reverse....only revs up...havent checked if prop will spin both way while in gear but one thing I did notice while trying to adjust the...
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    manufacturers WOT rpm ?

    anyone know the max suggested wot rpm for a mercruiser 470(170 hp) so I can figure out my best prop setup. Its a 1979 with a pre alpha mercruiser outdrive on a 17 foot fiberglass lund bowrider
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    prop size suggestions

    Its a 1978 lund with a mercruiser 470. Its a 4 cyl with a ford v-8 head on it so it pushes 170 h.p. The boat is fiberglass and according to N.A.D.A. it weighs roughly 2000 pounds. It has a mercruiser pre-alpha outdrive 1:1.85 ratio (i believe). At WOT the boat will reach 4500 rpm, not sure...
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    flame arrestor cause rpm loss?

    First off thank you to everyone who has helped me with this haunted engine I have, being the mercruiser 470....I took it out yesterday and ran dons fuel test, unfortunately the test was all perfect, more so the boat didnt act up as quickly as normal so I never got to test it while the bogging...
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    new symptoms of rpm loss

    I have posted about my 78 merc 470 "losing power & bogging down" under load only and only after running for a hour or so straight. If I let it cool or go back to the river the next day it runs fine for another hour or so...did the vacuum test on the fuel and it was fine now Ive come to realize...
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    fuel delivery fine...any suggestions?

    the fuel test ran fine....and again the boat ran fine for a hour or so before losing rpm's at wide open throttle.........so my fuels good...what else could cause the boat to lug ONLY, and I mean ONLY after it runs for a hour or so and never heats up...it just loses power and bogs after 3 grand...
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    MORE WOT problems on mercruiser

    I posted the other day about my wot problems and I appreciate the help but Ive yet to diagnose it and I have more information as to how and when its happenning. Ive read the 3 or 4 other wot posts and although mine seems similar in some ways, its got other symptoms far different. For...
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    loss of power

    I have a mercruiser 470 and it was running good....I put in new plugs and it ran good for a couple trips out, then toward the end of one boating trip it felt like it had kinda loping at high rpm around 4500....it wouldnt hold steady....now it wont really even stay over 4 grand consistantly and...
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    re-assembling....what oil and lube

    I have a pre alpha outdrive...is there oil in the top and bottom halfs or just top....and what kind do I use in each....also, what type of packing grease goes in the bell housing when you mount the outdrive...i cleaned the old stuff out cuz it was that OLD and brown and grimey. Is it just a...
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    what outdrives will fit

    I have a mercruiser 470 engine with a pre alpha outdrive? (boats a 1977,outdrive has a loop hole casted into the top) can i put a alpha upper on with my prealpha lower? And what other outdrives mount to my housing?
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    found lockup problem/now what?

    My motor wouldnt turn over as I posted the other day on my mercruiser 170 with pre alpha outdrive. I pulled the out drive,she fired up with barely bumping the key...made me happy and sad. I couldnt spin the spline coming out of the out drive and before pulling it checked the oil level which...
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    how do u check drive fluid level?

    anyone know how i check the oil level in the outdrive on a 1979 boat...i think its like a alpha outdrive, the motor is a mercruiser 470...i see one screw head about the size of a nickel that says oil vent???????
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    Stuck In Gear Or Locked Up?

    I just bought a boat two days ago and took it out onto the lake... I made one lap and was showing my wife how to drive it becuase I wanted her to pull me skiing. I told in an emergency just pull up on the throttle quickly...when I demonstrated it the boat died. When I turned the key all ill...
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