30 and 35hp power head interchangeability

[retroroy]

A neighbor of mine passed away and they put all his boat stuff out of the trash this morning. I just spent an hour dragging it down the street.
He was an avid fisherman but I guess his kids aren't.
They sold the boat because it had a title, but gave me the trailer, 15 motors, and a half dozen tackle boxes that got overlooked at the massive yardsale yesterday.
Apparently at the yard sale they thought the motors were worth a grand each and they didn't sell, today they were wheeling them out of the trash because they wouldn't sell.
He had 9 trolling motors, all 3hp Minn Kota transom mount models and one Riptide 58lb thrust, apparently they sold the only one newer motor he had.
The boat that sold was a '74 Starcraft SF16 in fair condition with about 30 coats of paint on it.
There are 6 35hp Johnson motors and two 30hp Evinrude motors. all between 1977 and 1985. There's one 89 Erude 4hp, one 60's Merc. 4hp, both run, two 15hp LS Erude tiller motors, two 9,9 hp Johnson SS tiller motors, and one older 18 or 20hp short shaft Gale motor that runs. My interest is in the 35hp motors and there's two with issues plus about 6 wheel barrow loads of spare parts. A half dozen lower units, a couple of power heads, and boxes of bits and pieces he saved over the years.
The fact that they opened up the garage and let people walk through and buy things and no one looked at the boat motors has me mind boggled.

1) There's a 1982 35hp Johnson long shaft motor with a stuck power head, it looks like a new motor condition wise but I'm looking down the plug hole and its rusted solid.
There's a 1985 30hp Evrinrude that's missing the skeg but its a short shaft with a seized up tilt pin and steering tube,. Plus there's another loose 30hp complete power head in a box marked 'good- low hours'.
WIll a 1985 30hp Evinrude power head go on the 1982 Johnson motor?

2) The one 35hp is a 1977 Johnson but with manual only start and no charging system, can I use the parts from the seized 1982 to make the 1977 tiller motor electric start with an alternator? The 1977 motor runs as is but has a really ugly looking wiring harness that's pretty well corroded. The '82's harnes looks new.

 

[saltchuckmatt]

Wow... Happy days and you scored big time. Those 80's ones are my fav but pretty sure they have compatibility issues with the 70's motors. Others will confirm.

As for the stuck one that looks good, pour tranny fluid and acetone in the sparky holes, wait a day, remove head and semi lightly tap pistons with a block of wood and a descent size hammer. If it breaks loose, add two smoke oil and spin with a drill and socket for awhile.

If all seems good, flatten the head (online instructions) and replace with new head gasket.

Check compression and report back.

Go buy a lotto ticket.

 

[retroroy]

I have the motor completely torn down now, only the two rods and pistons remain in the power head, and about 5 water jacket bolts and one coil bolt that broke off at the top remain. One piston is about 1/2" down, the other is just above the ports. The bottoms of the cylinders are lightly rusted but nothing bad, the top lower portion of both cylinders are well rusted with raised brown rust, the kind you see from mouse urine, but I don't see any way a mouse could have gotten above the pistons. I just thing they sat that long. The tilt pin is super stiff, almost immovable and oil and grease didn't help, so the bracket will need to come apart too.
The oldest of the 35hp motors is the 1977, the power head looks the same but the carb, intake plate, fuel pump, and wiring is very different. A few 35hp models have plastic air silencers on them, but not all of them. The 77 tiller model has the silencer and does not have the choke solenoid or a ring gear for the starter. All have 145 to 177 psi of compression.
I have the power head sitting face up right now with the cylinders filled with Evaporust I'll give that a day and see if it wants to move once the rust is gone.
I'm surprised its seized up, it doesn't look like it was stored badly otherwise, the paint is like new and the decals are perfect. It shows no signs of outdoor weathering and his garage was bone dry.

In the piles of parts there are a few sets of pistons in original OMC boxes but I'm not sure what they fit yet. There's about 9 bare 9.9/15hp power heads, a few look new, plus about 40 props, including a few SS props that fit the 35hp motors, and a few cast iron or steel props? They look to be painted cast iron. They're new and were in brown boxes shipped from a prop shop in Seattle post marked in June of 1986.
There are two of them, both are magnetic and appear to be cast iron and are marked only 10x13 in a square imprssion on the side. The inner hub is a brass/rubber pressed in insert.

There are boxes of carbs, all unmarked, most are the earlier 18-25hp style carb that was so common on the earlier motors but there's a good many sets of V4 carbs too.

They put more stuff out last night, I made five more trips dragging more parts and props back that they tossed. They're throwing things out without even opening the boxes or tubs. Regardless of the parts or their value, they've thrown away $300 worth Sterolite plastic tubs and about a dozen flip top boxes full of parts.
The old guy had nailed props to the perimeter of the walls up high using long gutter spikes with washers made of masonite. Instead of pulling out the spikes they took a saw and cut those 2x4's and put them out for the trash whole with the props all attached.
In one tub I dragged back to my garage this morning there's 6 new OMC aluminum props for 9.5hp motors. They also threw away two 9.5hp motors that he had in the rafters, one is a 1969 Johnson that looks new, the other a super clean Evinrude long shaft that has a broken anti cav plate, which looks fresh. They likely dropped it or threw it..
They know I've been taking all the boat stuff, and know I knew their dad but won't say come get it or clean it all out, they'd rather wait till midnight and put it out at the curb. They spent all day yesterday tearing through things in the garage throwing stuff outside as fast as they could get it off the shelves. The son had is truck backed up tot eh garage at the end of the driveway, and they'd fill the bed, and he'd pull up to the end of the driveway and stack the stuff at the road. I actually ran off a couple of scrap guys who were drove up as I was walking over to the pile.
The garage there is two story, the top floor was at one time a two room apartment but it was packed with boxes for years. The outside steps were removed long ago and the only way up was a pull down set of stairs. I had been up there as a kid helping him load some things up there but never really went up and looked arround. It was packed solid with no lights even 30 years ago. I doubt they've even scratched the surface in there. They probably can't wait to sell the place and get that cash in hand, but are overlooking any value in the things they're throwing away.

 

[saltchuckmatt]

Wow, what incredibly amount of compression....and cast iron propellers? Crazy.

Let us know when you wake up from your dreams.

Do you live in the states?

Post pictures.

 

[racerone]

They marketed stainless propeller in the 1970's.------They were teflon coated.----made of 400 series stainless ( magnetic ) that can show a bit of rust.----Teflon coating was cheaper than polishing.

 

[tphoyt]

I like to call the 400 series stains less steel.
But it is some tough stuff.

 

[saltchuckmatt]

We call them "log scissors" around here.

Yes, Tough stuff.

 

[retroroy]

The cast prop is black, it could be teflon I suppose.
Its a lot heavier than a Solas ss prop that I have for my boat, its at least as much heavier than the bright ss prop as the ss prop is over a stock aluminum prop.
I have two Snap On compression gauges, one is specifically for small engines and motorcycles, one Mac set, one Matco and one older Craftsman gauge.
The electric start models show between 131 and 177 psi, the rope start models are lower, between 110 and 122 psi.
As a comparison, when connected to shop air, which is set at a max pressure of 180, they all read within 1 or two psi of one another.
The lowest I've seen is show on an outboard was 77psi on an old 5.5hp I had here that i sold for parts. MY 1979 6hp kicker on my boat shows 102/103 psi with five pulls per cylinder. The 1968 18hp that came on my old Duranautic which was nearly impossible to pull start showed 185/180 psi. I doubled the head gasket on it so it would stop breaking ropes and knuckles.

After looking up each year 35hp, it looks like the engine families are 1976-79, and 1980 and up for the lower units.

The power head off the '85 bolts right up to the 1982, the only difference I see is a fuel enrichment solenoid vs, a choke. Right or wrong it looks like it'll work just fine. it'll just be a white Johnson motor with a black 30hp Evinrude power head on it.
Looking at the 1977, the oldest one of the lot here, it looks like the newer power head may even bolt up to that as well but I haven't actually tried.
I'm not sure if I'll leave the 30hp on the 35hp lower or not because I think I can likely free up and fix the original power head and put it back together, but its no doubt cheaper to just slap on the newer power head if I end up having to order any parts or gaskets that I don't have.


I sorted through some more of the props and found two more cast props, they're roughly twice the weight of an aluminum and all 10x13p.
A few look like they're sort of rusty where the paint is chipped, a few look like polished chrome under the paint. I don't think its teflon, just flat black paint. The edges, through prop area, and a few spots on the back edges have rough sand cast looking spots on a few.
Most of the aluminum props are 10x15p, all of the cast props are 10x13, and there's two 10x12p aluminum props as well to fit the 35hp motors.
I run a 10x15p on my 16ft aluminum boat and top out at about 5600 rpm on a light open boat.
In the pic, there's an aluminum prop to the right.

 

[racerone]

Few prop repair shops have a teflon " coating machine "---They just paint them black for show !!

 

[saltchuckmatt]

If it's heavy it's paint grade stainless.

Good luck with your motors, you obviously don't need any advice.