Evinrude Fastwin 18 HP 15032 Leaking Around Exhaust

[Crowsbeak]

I picked up this a 1960 fastwin a few years ago and finally got around to finishing it today. Started it up and ran it this morning but water was leaking around the middle four bolts on the exhaust cover. The two right side inner bolts were broken during disassembly and had to be drilled, tapped and time certs installed. I cleaned the gasket surfaces real good before reassembly and used aviation gasket maker on both of the exhaust side gaskets only. I Did not see any pinholes in the stainless baffle when I cleaned all the carbon off. I did install a new water pump impeller and water pumped great while it was running. I clened and tested the thermostat and know it was opening and did install a new thermostat gasket. And ideas on what to do next? Do I need to pull powerhead and reseal exhaust?

As an FYI when I bought this motor the lower piston was seized up. I got that pushed out and installed new lower piston, new crank, and new rings (top piston looked great). Found NOS gasket kit and proceeded to rebuild. Used the recommended quad ring in the lower seal, Installed new Head gasket and dressed head, resealed lower unit etc…. I have a lot of time and money into the rebuild so I’m hoping there will be some ideas on how to stop this so the lower piston doesn’t seize up again and motor is usable.

Thank you,

Jeff

1954 Evinrude 7.5 HP
1954 Evinrude 15 HP
1954 Gale 12 HP
1955 Johnson 10 HP
1956 Johnson 10 HP
1956 Gale 12 HP
1956 Evinrude 5.5 HP
1958 Johnson 7.5
1960 Evinrude 18 HP
1973 Johnson 6 HP

• This topic was modified 4 years, 9 months ago by Crowsbeak. Reason: typo

[Bob Wight]

When you had the exhaust cover off, did you check to see if it was warped? Did you resurface the gasket face on the cover? Did you apply gasket sealer to the cover bolt threads and under the head of the bolt? Did you tighten the cover bolts with a torque wrench or just bolt it down by hand?

Edit – your Fastwin sounds just like mine. Seized lower piston, installed new crank, one new piston and new rings.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

• This reply was modified 4 years, 9 months ago by Bob Wight.

[Crowsbeak]

Bob,

I did apply the sealer to the gaskets and bolt threads but not specifically under the bolt head. I did not resurface the exhaust cover only tclened them up with scotch brite. I did not use a torque wrench due to them being slotted/phillips so it looks like the power head is coming back off and will be performing some rework. I will get allen heads so the can be torqued properly.
Thank you for the quick reply and the advice. Also I can’t tell you how true your tag line is!!

1954 Evinrude 7.5 HP
1954 Evinrude 15 HP
1954 Gale 12 HP
1955 Johnson 10 HP
1956 Johnson 10 HP
1956 Gale 12 HP
1956 Evinrude 5.5 HP
1958 Johnson 7.5
1960 Evinrude 18 HP
1973 Johnson 6 HP

[Bob Wight]

You can get a screwdriver bit socket set to use with a torque wrench. As you found out during removal, exhaust cover screws can get pretty tight over the years and are easy to break off. If you have to remove them in the future, the internal hex on allen head screws may simply round off before you can get them to budge loose.

https://www.amazon.com/Craftsman-Piece-Drive-Screwdriver-Socket/dp/B01JSZREFG

There may be other issues causing your leaks so let’s see if some of the real veterans weigh in on this.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

• This reply was modified 4 years, 9 months ago by Bob Wight.

[dave-bernard]

is your bolts bottoming out ????????

[billw]

NOS gaskets can be pretty hard and non-compliant, too….

Long live American manufacturing!

[Crowsbeak]

Dave, The replacement bolts I used were all 1/4-20 x3/4″ which matched the originals in length exactly as I checked that prior to install.
Billw I assumed the nos with the asbestos would have been hard originally so never considered they would be too non-compliant to seal. I guess I could try to make one from Felpro that is a little softer to match the profile. I made need to do that anyway as one of the gaskets will likely break when I pull the exhaust cover back off.
Bob I used Phillips head for my replacement bolts because I couldn’t get a hex head and socket which was my original plan so I could check the torque. Maybe I’ll switch all the others to Phillips head and try a socket adapter and torque wrench as you suggest. Anytime I have tried using a torque wrench on a slotted bolt I always end up with a new scar!!

Thank you everyone for the great ideas and I’ll keep you posted on my results.

Jeff

1954 Evinrude 7.5 HP
1954 Evinrude 15 HP
1954 Gale 12 HP
1955 Johnson 10 HP
1956 Johnson 10 HP
1956 Gale 12 HP
1956 Evinrude 5.5 HP
1958 Johnson 7.5
1960 Evinrude 18 HP
1973 Johnson 6 HP

[dave-bernard]

just try a washer under the bolts and see. if the threads are not cleaned well even the correct bolts wont go all the way down.

[Crowsbeak]

Dave, sounds like a good idea. I will try to install a washer under the bolts first prior to pulling the exhaust cover completely off again. I will also re-chase the threads on the bolts and the holes and seal the bolts again and under the washer. I did chase all the threads and bolts prior to install and two of the holes did have the time-certs installed.

Thanks again for all the help and ideas.

Jeff

1954 Evinrude 7.5 HP
1954 Evinrude 15 HP
1954 Gale 12 HP
1955 Johnson 10 HP
1956 Johnson 10 HP
1956 Gale 12 HP
1956 Evinrude 5.5 HP
1958 Johnson 7.5
1960 Evinrude 18 HP
1973 Johnson 6 HP

[fleetwin]

dave-bernard wrote:

is your bolts bottoming out ????????

I was thinking this also…

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