1965 Mercury 1000, 100 HP Leaking

[etbill52]

Mercury 100 Hp O/B motor,
while out on lake yesterday the boat would only run about 10 mph, while I was driving the boat my son-in-law removed the cover he noticed gas on the block. We got to checking and around the front off the block, the cover on the block that the carbs bolts on was leaking on one side, you could see gas and air bubbles coming out. It starts up good and idles, ok but when you put it in gear reverse or forward it stalls out. When I was running it down the lake it sounded like it was chocking down, rpm sounded Low, (Tach is bad).
I went to day and got a compressing Tester, I will check the compression tomorrow. Also before we went out I set the linkage for the time advance to push it to where the stop set screw was already set at. How big of a problem do anyone think I have??

Every dark cloud has a silver lining, we did catch 2 flathead cat fish in 88 degree water

 

[WillyBWright]

Re: 1965 Mercury 1000, 100 HP Leaking

Sounds like you have a leaky crankcase. There's a thick cork stuffer gasket in there that's probably shrunken over time. You have to remove the powerhead and split the case to replace them. When you go that far, you're not that far from digging all the way into it and doing a complete overhaul. It'll never run right with a leaky crankcase and will eventually burn up from runninig too lean.

 

[etbill52]

Re: 1965 Mercury 1000, 100 HP Leaking

Thanks for the reply, Now I know what I have to do, couldn't tell any thing about the gasket from outside the motor, I was sure it had one of some kind or at one time did.

That motor is 3 years older then my marriage

 

[etbill52]

Re: 1965 Mercury 1000, 100 HP Leaking

I checked the compression today and all 6 cyls. were at 120 - 122, I had another motor same year, model, and HP started it up it run ok (didn't run it long ,was on water hose) I got it for parts checked compression on it 5 cyls. were around 125-130 the number 2 cyl. was down to 30. so I guess it will be for parts. On the one with compression 120-122, is this enough? or should I do more to it when I fix the leak.

 

[diaric]

Re: 1965 Mercury 1000, 100 HP Leaking

thats good for its age, all even so should idle smooth. will sometimes come up a bit with running and rings cleaning up. if i had it that far apart, i'd probably do rings etc.

 

[etbill52]

Re: 1965 Mercury 1000, 100 HP Leaking

thats good for its age, all even so should idle smooth. will sometimes come up a bit with running and rings cleaning up. if i had it that far apart, i'd probably do rings etc.

I think I will do the rings to I sure don't want to take it a part again. I ordered a parts list for that motor from oldmercs.com. I guess they would have the parts I need to rebuild it wouldn't they? Around here I go to a place to get a part for 1965, they can't find it, or tell me it is a bad number, no longer can order it.

Thank every one for your reply, maybe some day I can post some answers, and not all questions

 

[WillyBWright]

Re: 1965 Mercury 1000, 100 HP Leaking

Before you pull the pistons out, see where the nuts are on the connecting rods. If you can get at them, go ahead and pull them out. You can do it a cylinder at a time when you put it back together. Yours might have the nuts behind where you can't get at them. That makes it necessary to put the whole crank, rod, piston assembly into the block at once and that's quite of a feat for anybody. You'd need special ring compressors that you can only buy (or rent?) from a Merc dealer (and probably on eBay). If that's the case, you might want to leave it at resealing that leak for now, or plan on having a delaer drop the assembly in for you (an hour labor, maybe two).

A lot of stuff is no longer available from the factory, but overhaul parts should be. All you need at this point is an overhaul gasket set if you just do the leak. You just need a few of them, but you'll need others from the kit now or in the future for other matters. click me

 

[etbill52]

Re: 1965 Mercury 1000, 100 HP Leaking

Before you pull the pistons out, see where the nuts are on the connecting rods. If you can get at them, go ahead and pull them out. You can do it a cylinder at a time when you put it back together. Yours might have the nuts behind where you can't get at them. That makes it necessary to put the whole crank, rod, piston assembly into the block at once and that's quite of a feat for anybody. You'd need special ring compressors that you can only buy (or rent?) from a Merc dealer (and probably on eBay). If that's the case, you might want to leave it at resealing that leak for now, or plan on having a delaer drop the assembly in for you (an hour labor, maybe two).

A lot of stuff is no longer available from the factory, but overhaul parts should be. All you need at this point is an overhaul gasket set if you just do the leak. You just need a few of them, but you'll need others from the kit now or in the future for other matters. click me

I took the motor I got for parts all apart, you are right the nuts on this one is behind where I had to pull crank and all pistons, the ring on it were very bad, the number 2 that have 30 compression were so bad the alum.on the side of the piston were covered the rings. Thought I would see how hard the job would be and not start on the one on the boat. The Front cover of the power head that had some leaking, is the one the carbs. mounts on, and it has no gasket at all, I look at the one on the boat and could not see any part of a gasket. This motor ran fair I guess 2 weeks ago it would plane out and run about 30 mph. When we got it home I reset the linkage to advance the time more, thinking is would raise the rpm's more, things went down hill from there.
With the advance timing linkage off the dist. was turning by hand a lot more then the linkage would turn it, I set it to advance it more. Could this have caused the low rpm's and like of power?
And I have always said "if it works, don't fix it"

Sorry I have post's so many questions on the motor. There is no one around here knows anything about them.. Or no time for a question.

 

[sshdtree]

Re: 1965 Mercury 1000, 100 HP Leaking

dont pull it apart just run 25:1 in your first tank thatll seal up the rings and give you better comp. across, also let me get your email i might be needin some parts

 

[Old Browny]

Re: 1965 Mercury 1000, 100 HP Leaking

Hi Etbill Cant kelp you with the leaking problem but was just pondering if you engine is the same as mine. I am trying to ascertain the year of mine and I beleive it to be a 1965 with the engine no on top of the block ,punced in as 1769822 I would like to talk to anyone who has one of these motors .and will swap pics or other identifying parts of the engine etc Cheers and thanks....Old Browny