A warped/gouged head would show up in the compression numbers (i.e. above the pistons) correct? Not that it wouldn't have been a good thing to do, but doesn't seem to fit the symptoms I'm chasing...
There are two separate crankcases? Do you mean above and below the cylinders?
Given that I've checked the spark and as you say fuel is combined, I guess I need to take a close(r) look at the reed valves, maybe one got bent or put back incorrectly.
That's good news on the compression numbers.
Yes, it would be great if I could walk over and show you, but alas we're likely not in the same place. So I was looking for trouble shooting help, not sure what to look at next - that's why I came to the forum :)
San Antonio - I've been getting all my parts for this from https://www.marineengine.com/. That's part of my frustration - every time I need a part it's another $10 and 2 weeks in shipping :). Finding a machine shop to bore out the head would be actually harder - there are fewer and fewer of...
My dad bought this nice little 1967 Johnson in 1980 or so for our 18' aluminum sport canoe.
All the water passages had clogged up sometime between when my dad bought it used in 1980 or so to around 2010 when I stopped using it much. My son overheated it a couple times before we figured out what...
@racerone are you talking about something like this? I don't have one of those (yet). EDIT: Grabbed one from the auto parts store, yes nice strong spark across a 10mm gap. Sigh, thought we were onto something for a minute there.
Hm, that little spot shows up much better on the image than in real life - didn't even notice it before - it appears it might be a small spot of broken/chipped insulation on the coil to the top cylinder. Could that be causing a short to the flywheel maybe?
I also noticed that the plugs are...
The coils are in good shape, no cracking or breaks on visual inspection. Here are a couple of pictures. They may be OE for all I know (through they have an ebossed "M" on the side).
I laid the plugs on the block, and observed the spark as shown in the below. What kind of test device would I...
Ah, F_R, I see you have an "about" link in your signature that is broken, and shows to me as a missing picture.
I was just confused since I couldn't do step 2 in the original procedure. But now I'm thinking there is something bigger going on.
Compression seems a bit low to me - 80 bottom, 70 top. My manual says normal rule-of-thumb is 100+.
All the water passages had clogged up between when my dad bought it used in 1980 or so to around 2010 when I stopped using it much. I pulled it all the way apart, had a machine shop acid bathe...
