TOPIC: 1961 Mercury 700 need help

After lurking for the past few years I finally decided to jump in. Bought a 1960 American Marc Stardust with a Mercury 700. Boat has been sitting outside for many years so I decided to do some pre-startup checks including replacing the impellor and I've already ran into trouble. I got all the bolts loose except for the screw holding the trim tab. Manual says it uses a 5/16" Allen wrench. Tried that and it feels like the bolt head is stripped.

Scratch that. Turns out I had the allen wrench between the cap screw and housing and not seated in the screw. Played with it some more and got it out.

Lower unit still not dropping. Loosened 2 nuts on the sides. 2 nuts underneath and a cap screw behind the trim tab. Front still feels like its bolted on.

I also found a hole in the casting. Not sure what to do about it. Weld it?

If it is a full gear shift it may be the shift shaft is frozen. or either motor the studs may be frozen . if so I use a screw drive and wedge it between th lower and drive shaft housing to spread it.

Ya missed the one in the front!

ed-mc wrote: Ya missed the one in the front!

Thanks Ed.
I have a pdf manual and didn't see that one listed.

Got it apart. Barely a drop of lube inside. Going to replace the impellor, 2 gaskets and the shaft seal. Anything you guys would suggest I look at or replace?

Also,
Where do you guys buy parts?

More than likely the driveshaft seals in the water pump base are leaking. Also recommend you get a water pump "repair kit", which will have a new upper plastic pump housing with stainless cup, new gaskets, pump plate, etc etc.

Depending on the style of your pump base, you may find a newer plastic replacement for that, too. Or just replace the seals in the old aluminum base. Keep in mind that the flushing screw must be removed in order to pull the pump base.

I get most of my parts from marineengine.com, ebay, and boats.net. Marineengine.com is a great place to look up parts, as they usually will have a picture of the part. Invaluable when you're trying to find stuff, like your old-style pump base.

The black lower unit is obviously newer than your white 700, so you're gonna have to figure out what style L/U you have if you want to upgrade to a plastic pump base (or even get the correct seals for the OE aluminum base).

Keep in mind if you switch pump bases you may have to check/adjust the shimming of the base. Not usually a big issue but something to be aware of. Basically you want to make sure there's a bit of gasket "crush" when tightening the pump assembly, this ensures that the base will seal against the L/U housing and it's also pushing against the driveshaft bearing (i.e. a bit of preload). If you don't have a manual, lots of info online here: http: // boatinfo. no/ (take out the spaces).

Armed with part numbers, you may find a better deal on ebay. One seller I can heartily recommend on ebay is Wulffe Marine. They have consistently good prices and ship fast. Seller name "wullfemarine" on ebay.

HTH...........ed

Thanks for all the information Ed. I will check out the sources you listed.

Hello,
To my eyes, the lower unit has been repainted black over original Cloud White, especially based on the fifth picture of the cavities for the nuts on the underside of the anti-ventilation plate. As the underside of the trim tab area of the lower unit does not seem to show the water supply inlet hole original to a 1961 to much of 1962 year lower unit housing, it would seem that it is either a very late production 1962 Merc 700, or maybe a 1963 Merc 850 lower unit (all other similar vintage lower units which would have been painted originally Phantom Black at the factory if they lack the trim tab water pickup). However, I am still not understanding what has gone before with the trim tab area, as it looks like it has been welded, "puttied", or such. "To throw our hat into the ring", we would be happy to try to help if you should like to write to us: This email address is being protected from spambots. You need JavaScript enabled to view it.

Regards,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

With the help from Joe at www.fergusonpoolemarine.com/ I have enough information to order the right parts. Here

I also took ed-mc advice and ordered a kit.

More pics of the lower unit that has been sitting for years. Casting number to narrow it down even further.

Man is that an Old-Timer! It still has the pin-drive for the impeller, make sure you replace that pin!

And it looks like the pump base has only one oil seal. If you can find a compatible newer pump base, it'll have 2 seals in different places and that's a good way to deal with a driveshaft that's eroded in the seal area. The new double-seals should ride in different places than the old single seal. If the shaft is badly eroded, you can drive-on a stainless "Speedi-Sleeve" aka "Seal Saver" aka "Redi Sleeve". This will give a fresh surface upon which the seal's lips can ride.

Have fun with the repairs!...........ed

I tried to see if I could get the motor running today while I am waiting lower unit parts. The good news is, it turns over fine.

I am not getting any power to the plugs and the distributor is arcing to the middle carburetor. Is it a bad ground somewhere or something else?

I am going to try and post a video. Wont let me so here is a still shot of the arc.

I just noticed something missing. GROUND STRAP ASSEMBLY, CYLINDER BLOCK TO BOTTOM COWL?

Whoa, Mama! That's some strong spark! You might try putting the ign wire boot back in place on the distributor and then maybe it won't arc. If still an issue, try some dielectric (silicone) compound on the boot.

The distributor should have a ground wire from its metal body, to the block. Usually off a metal tab with a hole in it, thru-bolted with one of the manifold-to-crankcase bolts. And yes, definitely it's Most Desirable that the block, distributor, coils, cowling, etc etc all be on the same ground plane.

You could add more ground straps as you feel necessary, it certainly won't hurt things.

Last thought, the boot may have a tear in it that's causing a spark leak. So inspect carefully for integrity..........ed

Thanks ed. I didn't notice the boot. Found a bunch or wires in bad shape too. Did a compression test.
1=35
2=40
3=35
4=35
5=37
6=39

Got it running today!

must be misprint on the ######'S

Hmm. I better read up on it some more. Ordered a manual but it hasn't arrived yet. This is the first time I have ever tried to do one. Pulled one plug at a time and turned it over for a few seconds.

Lakeplay wrote: Hmm. I better read up on it some more. Ordered a manual but it hasn't arrived yet. This is the first time I have ever tried to do one. Pulled one plug at a time and turned it over for a few seconds.

Pull all plugs, crank the engine over until the compression gage stops rising. Gage calibration will affect the reading. If you get somewhere between 110-125 psi it's doing well.

More important is that they are all even with each other, it'd be nice to see a 5psi or less difference between cylinders. More than 10 psi difference and I'd start worrying.

But the main thing is to get it running well enough to tune it, then you can run some carbon cleaner thru it and that helps get carbon off the rings and can often improve a poor reading.

Thanks again ed. Really good information.

In case I haven't mentioned it, this is my first time working on an outboard. Hopefully, others will benefit from this thread also.

Correct compression numbers:

1=104
2=115
3=107
4=110
5=112
6=104

I am in the process of trying to take the powerhead off so I can replace a bunch of stuff while its on the bench and also repaint everything.

I followed this thread about a Mark 75, that has some great information from Dr_Frankenmerc and others but I am still have some questions.
www.fiberglassics.com/forum/mercury-outpost/130791-mark-75-powerhead-removal.html#131453

Dr_Frankenmerc wrote: Because of the way the shift shaft is connected, you will need to lift the power head, and leave the lower engine pan on the drive shaft housing.
You will need to remove the (8) nuts (9/16" wrench for the 3/8" fine thread nets)
You will want to remove the (4) small Phillip's head machine screws that secure the internal harness to the engine pan.
Disconnect the fuel hose from the lower fuel pump coming from the bayonet disconnect to the fuel tank.
Disconnect the wires on the (2) coils. Label them for later. Disconnect the high voltage (center) lead at each coil.
Disconnect the rectifier's main nut that secures it. (9/16" wrench)
Remove the small spring clips that hold some of the wires to the top edge of the engine pan.
Zip-tie the rectifier (with its wires still connected) up out of the way.
Remove the nut at the bottom end of the vertical throttle lever on the port side & push the small link out of the vertical lever. (3/8" wrench required)
OR,...If that little nut refuses to cooperate,...
Remove the shift cable connector outside of the engine pan (two 3/8" end wrenches or sockets required) Watch for the wave washer as you remove the related nut & cap-screw.
Then remove the cap-screw that the shift link swivels on in the bottom & inside surface of the engine pan. (9/16" wrench)
Remove the cotter pin connecting this link to the shift link inside the engine pan.
Push this main link that passes through the slot in the engine pan - into the engine pan.
Zip-tie this link up out of the way.
If you are working with a fresh water only motor, you can probably remove the small cap-screw (7/16" socket) that holds the ground strap from the engine pan to the lower aft area of the port-side water-jacket cover. If the cap-screw refuses to move, I would cut the ground strap, and deal with the seized cap-screw later while the power head is on the work bench where heat can be applied.
I 'think' that is all you'll need to disconnect,etc to lift the power head.
doc

I tried to gently pry it up with no luck at all so I plan on rigging up a hoist in the garage to lift it out but where do I lift it from? Do I need to remove the top cowl first? Anything else I'm missing?

You should be able to get a pry bar between the front powerhead stud and the upper motor mount yoke. The leverage you can get there will help bust the powerhead loose. There's really no good place to pry on other than that.

For powerheads that are really really stuck, the Good Doc Frankenmerc has developed a method of wedging sockets & washers under one of the back studs, then screwing the powerhead stud nut DOWNwards to leverage the powerhead upwards.

But you probably won't have to do that, your motor looks to be fresh-water use and I'd venture to say that once you get the gasket busted loose at the front, it'll come loose readily.

If you pull the recoil starter housing (tophat), you can rig off the forward and rear tophat mounting holes. Note that the lifting eyes they sell on eBay won't work on your engine; earlier flywheels have coarse internal threads for the puller, and later-style flywheels have fine threads. Unless you have a puller specially machined or can find one of the old ones that fit those flywheels, the eBay pullers just ain't gonna work.

BTW there is throttle linkage that you can see in one of the pics that has to be unbolted. The bell crank will go with the motor. You can get at the nut (it takes a 7/16" socket) from underneath; there's an access hole in the lower cowling for that. Just position the throttle arm so the nut is at the hole for access.

HTH........ed

I really appreciate all the help.

Keep in mind, I am removing the power head along with the bottom coil at the same time. I used a pry bar in the front and it popped up fairly easily, then I worked my way back using smaller wedges, but the very back still wouldn't budge until I noticed a screw on the inside of the cowl. Now I just need to wait for a strong buddy to get home from work to lift it out the rest of the way.

I took the dyna float covers off and broke most of the bolt heads off. That will be fun to fix. Guess I will try a left handed drill bit.

Found another bolt I had missed.

For those of you following this adventure, here's what happened today. I wrapped my 60 year old muscle bound arms around this thing and started lifting straight up. Got it way past the studs, while grunting and groaning and starting to feel a hernia coming on when I realized I wasn't tall enough to lift it another 2 feet so the shift shaft and exhaust tube (didn't know they was coming out too) would clear. So, back down it went, not particularly lined up with anything. Tried lifting it again while standing on a make shift platform but its now really in a bind. Hoping I didn't bend the shift shaft and the exhaust tube. Tomorrow I plan on moving it to the same pond I last saw my golf clubs, with the plug out.

I wouldn't attempt to lift powerhead and lower cowling in one big lump. As you found out, it has to go way up. Better to separate the lower cowling from the powerhead and lift the powerhead as a separate unit. Then, you can deal with the lower cowling by itself, which is a piece of cake.

Look at it this way: there's a gasket between the powerhead and lower cowling; and another gasket between the lower cowling and the mid-section (exhaust tower). So, you're gonna have to have it all separated anyway, to replace those (2) gaskets.

You can reinstall the lower-cowling-to-mid-section 1/4-28 bolt and this will help to secure the back of the L. cowling while you're pulling the powerhead.

Regarding the frozen stainless bolts, that what a Mercury Wrench (propane or MAPP torch) is for! On the nubs that are sticking out, you may be able to heat the area and latch onto the nubs with some Vise Grips. MAPP gas has more BTU's than a propane torch. I use a propane bottle on a MAPP torch head and for most jobs it works very well. But MAPP gas will heat the part up faster and for stubborn stuff, works better.

Failing that, the correct repair is to drill out the busted bolts and install a Heli-Coil stainless insert. You'll have no luck trying to drill out the bolts undersize, then tapping out the remaining stainless. The tap will gall & break off due to the hardness of the material.

Drilling the bolt out fully with at least Titanium bits, followed by the appropriate-sized drill for the Heli-Coil tap (it'll say what size to use on the tap), works great and is a very strong repair.

BTW if you use either marine boat bearing grease (water-resistant) or a thin coating of Permatex #3 Aviation-type gasket dressing on all bolts/studs, they'll never seize again. This is something you learn after years of experience with Salty Dog motors. Salt and other corrosion products build up around the bolts and mechanically locks them in place This also affects motors that have been run in brackish bodies of water.

HTH and take care of your back and other body parts!!!!.............ed

Made some progress over the last few days. From reading some archives here it looks like I need to remove the flywheel in order to replace the timing belt. The service manual states to line up the marks when reassembling, but it looks mine are off before I get started. Should I make new marks or did the belt jump? Also, please look at the attached pictures. Does anything jump out that I should replace?

Tia

On the timing marks, you'll need to remove the pulley cover which is held in place by one bolt with 5/16" head. Once the cover is off, you'll see the dist. pulley has ribs. On one of these ribs is cast an arrow, which must point straight at the timing mark on the flywheel for proper belt alignment. At that time the arrow should also be pointing to the centerline of the crankshaft.

The dist. cap looks good, I would give it a blast of carb cleaner or otherwise suitable degreaser just to remove any oily deposits. Make sure the carbon center contact is free to move in its hole. If it's bound-up, remove the contact and its spring with an unscrewing motion (helps get the spring out), clean the contact and the hole. Reinstall with a screwing motion to help get the spring back in place.

Are you going to service the points? That's another level of fun! Be careful when removing the rotor, if you do much prying on the lower part it'll bust right out. Grab the mid-portion with your fingers and give it a stout pull, it should come off the shaft.

At any rate, judging from the arcing to the carb, you have a pretty good spark so maybe best to leave it alone unless you weren't getting spark out of one of the coils.

Cheers.......ed

I ended up using a harmonic balance puller to remove the flywheel. Had to buy the correct bolts. 5/16"- 24. Free rental at O'reillys. Do I need snap ring plyers to remove the rest of the distributor?

>Carefully remove the belt from the dist. drive pulley.

>VERY carefully pry the pulley upwards with 2 flat-bladed screwdrivers, 180 degrees from each other. Or use an appropriate gear puller if you've got one with thin teeth that can get underneath the pulley. Usually she'll come right up with no issues, if not, you're gonna need to soak the shaft with penetrating fluid and possibly heat the pulley.

>With the pulley removed, there are (3) bolts you'll see that hold the distributor drive assembly in place. Undo the nuts from below and the whole drive assy will drop out the bottom.

Note that unless you're doing a complete disassembly of the powerhead, you really don't need to pull the drive assy. Very seldom have I ever seen any problems with it. Long as the bearings are smooth and the economizer collar moves freely, there's nothing to service on the drive assy except the grease fitting(s).

Thanks ed. It popped right off. The plan is to disassemble most everything as a learning experience and to repaint/repair everything. Also to help other beginners like me in the future.

Yikes. This doesn't look good. It was filled with sand, the shaft is pitted and the gear housing cover seams to be seized up. I tried beating on the tabs and it hasn't budged. Besides buying to tool (91-30291, 91-53126) is there a better way to remove it?

You're tempting fate trying to get that apart. Do the driveshaft and propshaft rotate smoothly? If so, I wouldn't attempt it.

You're risking breaking the gearcase, the only way you're likely to get the gearcase cover ring out is to carefully drill it out. On a clean freshwater motor, you might be lucky enough to have the tool work to unscrew the cover ring, but on one that looks as nasty as yours, the threads will be loaded with corrosion products, which mechanically locks the ring in place.

Once the gearcase cover ring is removed, you'd need a ton of heat on the gearcase and a slide hammer on the end of the propshaft in order to pull the propshaft/gear carrier out.

Once you remove the thrust hub you can gain access to the propshaft seals. These can be removed and replaced without pulling the gearcase apart. You may find that things don't look quite as bad once you clean up the area with a wire brush.

The pitting in your photos is just on the propshaft where nothing keeps oil inside the L/U and water out. It won't affect the operation of the outboard.

What's more important is the integrity of the propshaft where the oil seals ride on the shaft. So you do need to pull the thrust hub off to inspect that area for corrosion, scoring, leaks, etc.

So, in conclusion: if it ain't broke, don't fix it. Clean it up and then check the propshaft seals, replace if needed. If gears are smooth and nothing's broken, don't tempt fate by pulling it apart.

Just IMHO................ed

Thanks again ed. They both turn smoothly. I will take your advice and just replace the seals.

Starting sanding some of the painted parts today. Cheap sander works fairly well so far.

Having trouble getting the handle off the top cowl. The drawing calls the rear bolt a "Bushing, rear handle stud". Got the nut off but still stuck so I put it back to protect the thread on and hit it several times. Still wont come apart. Does the rear stud fit into a slot like the front? I tried sliding the handle off the rear stud but its not moving either.

From what I recall, that rear stud may be spot-welded into the chrome top handle. So be really really careful with it!

Looks like the stud is stuck in the recoil housing and to get that outa there you'll need to heat up the surrounding metal to expand it, then carefully tap the nutted stud to bust it free from the housing. It might help to soak the area in penetrating fluid for a few days then hit it with heat, just watch out for flamage (I'd do it outside).

Gonna look really sharp when you're finished with 'er, keep up the good work!!

Man am I glad to find this forum - I got here from Peter 1708 on YouTube answering my question. I have this exact same outboard. It's been in the family since 1964 when my dad bought it with a slightly used Dorsett 15' El Dorado in Seattle. Cost was $1500. It hasn't been started since about 1989 (carb flooding). I've wanted to dive into it for years but didn't have the knowledge and didn't know how to source parts and service info. I've worked on cars and motorcycles a lot and only changed the plugs on this outboard. I do know that I forgot to drain the lube out of the lower end one winter and it must have had water in it. Hopefully it didn't break parts and just pushed a seal out or something. Anyway, it pulls through OK but I besides the carbs and lower end problem, I couldn't get the prop off. Could someone point me to a service manual?
I read through the posts to and from Lakeplay and so a lot of my questions have already been answered. Have carbs for this engine been addressed? Thanks, John

This is where I bought manuals. Make sure to buy the parts manual too. Narrow down the serial number first.

www.marineengine.com/parts/mercury-outboard/index.php

store.oldmercs.com/default.asp

ed-mc wrote: From what I recall, that rear stud may be spot-welded into the chrome top handle. So be really really careful with it!

Looks like the stud is stuck in the recoil housing and to get that outa there you'll need to heat up the surrounding metal to expand it, then carefully tap the nutted stud to bust it free from the housing. It might help to soak the area in penetrating fluid for a few days then hit it with heat, just watch out for flamage (I'd do it outside).


Gonna look really sharp when you're finished with 'er, keep up the good work!!

You were right again ed. Unfortunately I tried to twist the handle back and forth to loosen it, and broke the stud. Then I cracked the housing while to trying to beat the stud out. A friend of mine with access to a machine shop thinks he can repair both.

I found a depression on the exhaust manifold cover that has me concerned. It appears it got pretty hot at some point and there is carbon or oil built up the crankcase across for it. I started to remove the cover and already snapped a bolt. Looking for advise on what I found and how to proceed.

Lakeplay I checked the sites you listed and found Marine Engine has a Master Service Manual (blue cover) and Old Mercs has a Mercury Service Manual (Engine specs, maint & repair procs) (white, red, and black cover).
Do you have an opinion on which would be better?
Also Old Mercs has the parts manual printed or download. Leaning towards printed

My engine is definitely a 1961 with a A1420754 sn. don't know what the A is for. Full Gear Shift.

I bought both printed from Old Mercs. $98.07 total.

Buildlite wrote: Lakeplay I checked the sites you listed and found Marine Engine has a Master Service Manual (blue cover) and Old Mercs has a Mercury Service Manual (Engine specs, maint & repair procs) (white, red, and black cover).
Do you have an opinion on which would be better?
Also Old Mercs has the parts manual printed or download. Leaning towards printed

My engine is definitely a 1961 with a A1420754 sn. don't know what the A is for. Full Gear Shift.

The service manual I bought hasn't been very helpful to me yet. It goes into great detail about some stuff, but doesn't explain procedures very well.

The parts manual is a must have. Easy to read exploded drawings with part numbers, qty needed, etc.

Maybe someone will chine in on whether the master service manual is better.

Yes that would be helpful. Maybe I will try the master service manual and we could compare to see if there are differences.

mercury outboard service manual . mercury outboards 1965' and prior part # C-90-25500. all the mercury service manuals have useful info Glenn's marine series , Seloc, CLYMER. MERCURY 1965' and prior being the best.