1973 16’ Monark repair/rebuild

Bantou · Sep 10, 2024

Figured I’d compile all of this into one thread. I’m replacing the transom and doing a tune up on an ‘88 15hp Johnson. Boat is in pretty rough shape overall but has some good bones and is water tight except for a slow leak from the drain hole. I’m not entirely sure that the leak wasn’t caused by a bad plug as much or more than the abused drain hole.

There is a stress crack on the top of the transom that I’m debating how to fix. So far, the consensus is that I need to pull the existing rotten wood before figuring out if/how to address the stress crack.

Motor is getting a carb rebuild, new plugs, and new impeller. Based on a video I posted, the group is leaning towards it also missing on one cylinder. I won’t be able to trouble shoot that until I get the carb rebuilt and the fuel tank gets here though.

Once the big issues are fixed, I’ll work on some “quality of experience” upgrades like a Bimini, more comfortable seats, etc.

Bantou · Sep 14, 2024

Pulled the transom wood this morning… it was worse than I thought. The piece of the original transom next to the aluminum had totally rotted away and 2nd piece was about 1/3 gone. Instead of replacing the transom wood, the previous owner just slapped another piece of plywood on and left a void behind the wood.

I used an angle grinder and punch to pull the rivets on one of the brackets. I’ll probably wind up pulling the other bracket before putting wood back in it.

I cracked the transom further while removing the wood. It is definitely going to need a welder now.

Stand Up · Sep 15, 2024

It does look a little rough. It will come together with the correct attitude, and it sounds like you do. Keep posting and inform us all of your progress. Thanks for posting.

Bantou · Sep 15, 2024

“Come together” is kind of a loose term for this project. I’m doing this so I have a boat that I can put in the stumps without worrying about scrapes, dings, etc. She is very much going to be a “Bertha” not a “Betty”

LDUBS · Sep 15, 2024

That explains why the ply edge was proud of the transom cap in the original pic. Anyway, you are on the road to getting it fixed now. I look forward to watching how it all comes together.

Bantou · Sep 16, 2024

After talking with an old river rat, I'm considering doing either a 1/8" or 3/16" aluminum patch instead of having it welded. He raised a good point that the patch would provide a lot more support than rewelding it ever could.

My big concerns with the patch are the cost of aluminum and the top cap. I'd either have to have the aluminum broke to match the top cap, do it as two pieces, or have the top cap welded and then patch. If I'm having the top cap welded, I might as well have the rest done while it is in the shop and just forget about the patch since I'm only putting a 15hp on it.

Bantou · Sep 17, 2024

I thought I had deleted the above comment instead of posting it.... I reasoned out my answer while typing and did not intend to post it. Leaving it in though so I have a record of what I was thinking at the time lol