Removing the power head for a 1966 20hp Johnson, model FD-20C

Hi all. Been having some motor issues lately. The trusty old 20hp starts right up, even after sitting for awhile, but subsequent re-starts were/are very difficult. I eventually noticed a small amount of water leaking/bubbling out from around the exhaust port and one small area of the cylinder head :/ I think this may be affecting the compression once the motor is warmed up, making the re-starts more difficult. Regardless, the 50+ year old gaskets are shot and need to be replaced. At this point, I may as well replace all of the power head gaskets while I'm at it. It looks like removing the power head should make the job much easier (famous last words) and give me access to all of the old, stubborn bolts. However, I'm not exactly sure how many bolts hold the power head in place and/or where they're located. I'm guessing there are 6-8, but I can only see about 4. Here's a link to the parts catalog with exploded diagrams, if that helps.

Vintage Evinrude Johnson Outboard Parts & Diagrams - Catalog 381415

Also, how many/what type of gaskets should I expect to have to replace. I believe I'll need 1 head gasket, 2 exhaust gaskets, 1 power head base gasket, 1 reed coverplate-to-manifold gasket, and 1 t-stat housing gasket. Are there any others I'm missing?

Thanks.

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

I think I sorta got an idea of where the powerhead mounting bolts are now. Here's a pic with arrows pointing to each of them (I think). Can y'all see any I might be missing? Thanks.

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

That looks like all of them kfa.That front one is usually a pia, at least it was on my `75 . You gonna put a lower crank seal in when you have it down that far (possible top seal as well). Did you notice any fuel bubbling from the case halfs when it was running?
Maybe a new carb to intake gasket. What is your compression on your motor? I picked up a `66- 20hp myself this summer that was stuck from sitting for 30+ years. I took the head off and soaked it for a few days and got it to free up. It had a small spot of rust in top cyl that cleaned up like new as it was just from condensation. Put the old head gasket on to try it and it fired up, has fantastic compression.

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

I'm not sure about this but is there a stud from the exhaust hsg poking up from the exhaust hsg with a nut on it holding the p/h on ??

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

There are a couple more screws (as I remember), center top and bottom in the picture. At least one of them, I'm not sure about the other one. The front one is a #3 Phillips head, or a special small hex head, you may find either. It's up in there where it is hard to see, but it can be accessed. You don't want to mess up that Phillips with the wrong tools or you will have a problem getting it out.

There is a plastic restrictor in the water outlet at the rear of the powerhead/exhaust housing. They melt from overheating, if it has ever happened. Don't be surprised if it is damaged.

Reed plate/intake manifold gaskets rarely leak unless disturbed or re-used.

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

recently removed the p/h on a '72- 25 hp....if I had it to do over again, I'd stand it on its f/w to at least loosen the fasteners...knowing you use this in salt as well as freshwater, don't hesitate with the heat if need be

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

Will do. I like the flip idea. Once (if) I get the powerhead off, it should hopefully be pretty easy to remove the bolts on the head and exhaust port. I've been able to loosen most by hand, but a few are below the lower cowl line and there's no good/easy way to get to them. I don't currently have a torch, unfortunately. Would one of the small mini, butane torches from HF work? If so, where is the best place to apply the heat, to the head of the bolt, or to its housing? Thanks.

Re: Removing the power head for a 1966 20hp Johnson, model FD-20C

If you're going to use heat, get a mapp gas kit at most hardware stores. You heat the area around the bolt, not the bolt itself.