TOPIC: Merc 400 Winterizing - Did something stupid

Need your help out there. Was winterizing my 1960 Merc 400 and got a little carried away with trying to get all the water out of the bottom end. I removed a screw which I thought looked like a vent, and heard a little "tink" as the nut dropped off on the inside of the lower unit. See pics.

So, the big question. What do those four screws hold, and will that nut cause problems on the inside?

Is it worth just pulling the powerhead off the lower unit? I've never done that. Do you just remove those six or eight obvious nuts and it lifts right off?

A little help from someone who has been there would go a long way towards relieving my anxiety about this.

Those 4 bolts hold the upper mount on. Yes you must remove the powerhead to access them. pretty strait forward in removing the powerhead. need help call me 1 914 310 7086 Dave.
surprised it came out they are usually frozen in many years ago.

So I should be able to just remove those six or eight bolts and pop the power-head off? And as long as I don't turn the shaft or motor, alignment shouldn't be an issue going back together?

I guess I have a winter project now - not that I needed another project. The old "Don't fix it if it aint broke" adage is going to haunt me on this one.

Thanks!

Yes, those 6 bolts will do it. Since you are winterizing drain the oil in the lower unit and make sure there is no water in there. Actually thats the only part of the merc 400 that is not self winterizing. Water will drain out everywhere else if the motor is vertical. Also, do not store your engine tilted up on the boat. Water will collect in the exhaust portion of the lower unit and crack it if it freezes. So, motor down, drain the oil, check for water. Re fill with fresh oil ready for spring. If you found water you can re do the seals over the winter.

Actually (8) nuts on studs need to ne removed to lift the powerhead.
Also,...A few things need to be disconnected before lifting the powerhead separate from the engine pan.
I disconnect the fuel deliver hose at the fuel pump, remove the throttle stop plate from the from of the magneto, then advance the throttle linkage aft until you can put a 7/16" socket up through the engine pan and onto a nut on the underside of the bronze throttle link, remove the (4) small Phillip's head machine screws that secure the internal electrical harness to the engine pan, and the (3) wires going to the rectifier. (2) yellow & (1) red, then disconnect the white - or perhaps 'salmon' colored wire going to the magneto.
There is also a red ground strap going from the lower pan to the port side water-jacket cover on the port - aft corner of the water-jacket cover. be very careful when removing the 1/4 x 20 cap-screw securing the ground strap as typically corrosion can cause the cap-screw to break. Perhaps not an issue since you were so lucky in removing the one screw securing the upper rubber mount that brought this issue to attention.

Now you can lift the powerhead.
If it won't immediately lift,...You will need to post so we can explain the safe places and ways to apply a pry to separate the powerhead from the pan gasket.

doc f

Thanks guys, I really appreciate the help on this. I'll let you know how it goes once I get into it. May be a while as weekends at the lake are few and far between now that the frost is on the pumpkin here in Michigan!

As a way to give back to the group - On a totally different topic, I just built a pizza oven at the cottage, so if anyone wants to talk pizza (and beer), I can provide information on something I actually know about.

Pizza oven construction - very knowledgeable
Pizza oven use - learning
Beer consumption - expert

I think you may be onto something, you should hold a pizza & beer party for the powerhead R&R. Guarantee it'll get done fast! Recommend beer After you're done, though!!

I would be glad to host a pizza a beer party for any of the forum experts who want to lend a hand.

Just remember my motto - Limit of one until the job is done!

I'm just suprized those bolts came out so easy Usually is a total pain to remove. Where are you located in Michigan?

Travis

I wish it would have been a little harder to remove. Then I might have taken the time to think about what I was doing!

I'm on lake St. Helen, which as you may or may not know is about 2.5 hours north of Detroit straight up I-75.

Or if you are familiar with Houghton lake - I'm about 25 miles east of there.

Its a small lake that also happens to have an ORV recreation area right next door. That way I can enjoy both land and water based motorized toys. I do love the smell of a two stroke in the morning!

Travis,

We should try and get some of the Michigan group together next summer.

Or is there a good vintage boat meet in Michigan already that I should know about?

Where are you located?

Sound good to me! I'm in Novi many inland lakes all thru Michigan I grew up on the St. Clair river & flats around Harsens Island. If you were closer I'd help you out .

Travis
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Travis,

I appreciate the offer. I'm in Shelby TWP, but my boat is up on Lake St. Helen.

It would be nice to get some of the Michigan FiberGlassics community together - not sure how to do that though.

If there are any good event organizers out there - I'm in!

Gadabout,

How about just putting some silicon on that bolt, shove it in there and "Fugget about it".

This is easy for me to suggest since its not on my boat. I think you can get the nut out by simply dropping the lower unit. Putting the nut back on the bolt would be a trick without pulling off the powerhead.

Thanks,
Terry

Terry,

Yea, I was thinking the same thing. Can that nut get into any trouble where it is laying?

If I get time this winter, I plan to go ahead and pull the powerhead off, but if not, it would be nice to know I can just run it like it is next spring. (With the hole sealed up with Silicone.)

I don't want to cause more trouble due to laziness, but I also don't want to cause more trouble tearing something down that is not really that big an issue. After all, it was going overboard on winterizing that got me into this pickle in the first place.

Gadabout

I would repair it . it does hold the upper motor mount. just me I would not take the chance.

I'm sure you are right Dave. I'll get on it at some point this winter.

Just got our first good snowfall here this winter so not much else to do unless I buy that snowmobile I've been thinking about...

The nut that escaped is brass, so a magnet won't help either.
Since that nut & related machine screw 'voluntarily' came right out, I agree with Dave in that it is best to bite the bullet and go ahead and 'git-r-dun' right.
doc

Yeah I would want it done right on my boat too.

Still thinking about this and it may be possible to put that nut back on without yanking the powerhead.

First drop the lower unit and retrieve the nut. Somehow put an extension on the handle of a breaker bar and then reach in there with the nut in a socket. With patience you may be able to get it started.

Terry

wont work like that. the mount cover is cast to fit 1/2 of the nut. good luck.

I agree with Dave,...Virtually impossible in this situation.
Do you need pictures of what you're up against? Just ask.
No big deal.
doc F

Thanks for all the suggestions guys.

I'm headed "Up North" later today to work on it. (Here in Michigan, "Up North" is about 2 hours north of Detroit - its where a lot of people go to boat, snowmobile, and otherwise have fun in the good ol' out of doors.)

I think I will just go ahead and pull the power head off. Might as well do it right if you are going to do it at all as they say.

Doc, any pictures you have that would guide me on my way are much appreciated.

BTW: Is this a one man lift type job (Merc 400), or do I need to rig up some type of pulley system?

I'll try to provide some feedback once I get through it to help any other novices like me who may be planning a job like this.

Thanks for all the support guys,
Gadabout

IF you are strong it can be a 1 man job. but it is easier to reinstall the power head with help be it human or mechanical.

Roger that Dave - thanks!

I have many pics but always a chore to post here. FYI you will probably need a powerhead gasket if you pull the powerhead.

Travis

I hear you on the pictures.

I dived in anyway and the short story is that I found the nut laying down in the bottom and got it re-installed. Haven't put it back together yet, but it is ready to re-assemble. See long version below for details.

The long story. Apologies to Doc right from the get go as I pulled the pan and the powerhead as one unit. Doc, after reading your instructions and looking at things up close, I think what you were describing is pulling the powerhead and leaving the pan in place?

Since I was alone, I rigged up a lifting sling and used a heavy duty ratchet strap to do the lifting. See below.


If you try this method, make sure the ropes / strap cannot slip. I added the screws in the picture after learning this the hard way. Would probably bolt small chains to the crossmember if I had it to do over again.

The only problem with lifting the powerhead pan and all was the rod towards the front of the lower section (the reverse gear shift rod?). This was the only thing connecting the two pieces at this point. I maybe could have lifted it way up and gotten this free, but I didn't want to try that by myself. I ended up rotating the powerhead 90 degrees to the lower unit and was able to get access that way. You can see this if you look closely at the next pic...

I tried to retrieve the nut with some goopy gasket sealer on a long stick, with no luck. I ended up whittling the stick to the same diameter as the nut and lightly drove it into the hole. This worked like a charm. )I knew this was going to be trouble when Doc said it was brass - there went my rare earth magnet on a stick idea.)

So that's about it. Since it takes two hands to safely lower the ratchet strap, I am going to wait till I have help to reassemble. Other than lining things up and a gasket (Thanks Travis), anything else I should watch out for?

Doug

Since you removed it with the lower pan I would remove the lower unit before installing the power head back on. makes things easier. then install the lower unit last. Trust me.

Dave, is that so I can get the shift rod and the driveshaft lined up and engaged properly? What does the bottom end of the shift rod look like - I can't seem to remember from when I had the bottom end off about two years ago.

"Since you removed it with the lower pan I would remove the lower unit before installing the power head back on. makes things easier. then install the lower unit last. Trust me. "

I agree with Dave.
The water tube, and the shift shaft and related cams are the reasoning for this.

One way to do this is:
Remove the lower unit.
Raise the power head and engine pan assembly way up, and install the water tube back into the engine pan.
Lower the the power head and engine pan assembly back down into the drive shaft housing (DSH). Index the shift cams, and shift shaft.
Tilt the beast up onto the tilt lock.
Reinstall the lower unit while guiding the shift shaft & water tube to their exact location.
Test to see if you have all gears F-N-R.
This may be the easiest way, but you do need to be able to raise the power head & engine pan assembly high enough to allow the shift shaft & water tube back into the top end of the DSH.

The other way is:
Remove the lower unit.
Separate the engine pan from the power head.
Insert the water tube into the engine pan.
Check orientation of the (2) shift cams (one in the bottom of the DSH & the other on the lower unit's shift shaft)
Install the lower unit, while guiding the water tube and shift shaft into the correct positions. (make sure that the engine pan's shift shaft doesn't simply raise up as you push the lower unit back up tight against the DSH - this would indicate that this shaft isn't properly mated to the lower unit shift shaft).
Also make sure that the water tube doesn't raise up through the engine pan as you push the lower unit back up tight against the DSH.
Confirm that you have both the water tube & shift shaft properly positioned, and confirm you have all gears (F-N-R).
Now you can lower the power head back onto the engine pan.
The only thing you will need to do if the power head doesn't want to go clear down onto the engine pan is rotate the flywheel (clockwise only) until the crankshaft splines align and drop onto the drive shaft splines.
I prefer doing it this way.

Either way, make sure that neither of the two gaskets are torn, or if so, replaced with new ones. The gasket between the power head and the engine pan,...And,...The gasket between the engine pan and the DSH.
This is a good time to check and clear the tell-tail holes in the engine pan & in the bottom surface of the port side exhaust cover.

doc

OK, I think I see what you guys are saying. Just to be clear, my water tube is still in the drive shaft housing. It did not "pull up" with the power head when I raised it like the shift shaft did. So my understanding of what you are saying is that I need to raise the power head way up till the shift rod is clear of the DSH, and then pull the water tube from the DSH and install it in the Power Head before lowering the power head back down? In other words, if I just lower the power head back down without doing the above, chances are that the water tube will not re-engage in its female socket properly?

BTW: The water tube connection is just a friction fit on both ends right?

The part about pulling the lower unit to make sure the shift shaft and the water tube get re-engaged in the lower end makes sense - I think I'm tracking what you are saying there.

Sorry to be such a pain - just don't want to make matters worse.

Doug

Doug, one comment on the water tube being stuck in the lower unit, you should pull the lower unit and pull the water tube out, so you can inspect the rubber grommet at the pump end and replace if it's in bad shape.

I've seen 'em where salt or other corrosion products have built up around the grommet to the point that the grommet has squeezed the copper water tube and crushed it. Your motor looks like it's freshwater-used, but the water tube is supposed to be in the lower pan when things are reinstalled.

I agree with Thom; his method #2 is really the correct way to reassemble the engine. If the lower pan does not want to separate from the powerhead, very carefully tap with a rubber mallet all around the perimeter of the lower pan and it should come off.

While you've got it all apart, check the upper rubber water tube grommet. If it's hard as a rock or deteriorated, it should be replaced.

I prefer to lay a thin coating of Permatex #3 Aviation-type gasket dressing on the i.d. of the grommet hole before inserting the grommet. Then a thin coating on the water tube where it contacts the grommet. Same for the pump grommet except use a good waterproof grease on the water tube. This keeps things from binding/seizing and helps the water tube easily slide into the pump when reinstalling the lower unit.

Anyway, all this will cost is a couple of gaskets and a bit of time. IMHO, well worth it!

BTW, how long has that impeller been in there? If you don't know or it's been quite a long time, this is a good time to replace it.

HTH........ed

Ed,

Good point on checking /replacing those rubber grommets.

Impeller should be OK as I just replaced it a couple of years ago.

OK, finally got some time to work on the boat again, but the news is not so good. I pulled the lower unit as suggested (in order to reassemble the powerhead to the drive shaft housing) and then lowered the power head down onto the drive shaft housing without too much drama. Everything seemed to go back into place with no issues and I bolted it up.

Then I reinstalled the lower unit being careful to engage the driveshaft and the shift shaft. Everything seemed to click into place with a little wiggling as I pushed the two pieces together.

Only problem now is that the control lever does not want to stay forward when I try to shift into forward. It just returns to the neutral position on its own (engine off sitting in the garage). It does seem to shift into reverse with no problem. Maybe something is preventing the shift shaft from turning and its just twisting it when I try to go into forward gear?

Help! I really hate to tear this whole thing apart again.

Anyone have any ideas of what I might need to do to fix this?

Unless you have a control box & related shift & throttle cables, this Merc will "jump" into forward gear easily.
More importantly,...Are you positive that you got the water tube properly aligned and into the lower unit?
doc

Doc,

Thanks for getting back to me. I'm not sure what you mean by this statement... "Unless you have a control box & related shift & throttle cables, this Merc will "jump" into forward gear easily." I do have a full set of controls hooked up to this motor. What I am saying is that when I am in the front of the boat at the pilots station and move the control handle forward, it just returns right back to neutral like its on a spring or something. It does seem to go into reverse normally, just not forward. That's not normal is it? At least I don't remember it acting that way before.

The water tube is another issue. I know Dave told me to remove it from the lower unit and install it into the power head first, but it would not come out of the lower unit. I wrapped rubber around it and tried to twist it a bit to get it free but it wouldn't budge, so I just installed the lower unit with it attached. (Sorry Dave for not following your advice, but I tried.) I have actually done this once before when I did not know any better and it actually worked fine, so I thought it was worth trying again. Even if the water tube missed the socket in the power head, that wouldn't effect my shifting problem would it?