fleetwin wrote:

OK, so the engine doesn’t actually stall out due to lack of fuel.   Did you pump the primer bulb at WOT?  If so, did it help?

I’m assuming the engine is running on two cylinders.  Did you check the linkage?  Perhaps the linkage/tiller handle is meeded up and the mag plate isn’t advancing all the way.  Perhaps the linkage is messed up and the carb isn’t opening all the way…

The engine did finally die out on me when I was trying to run
it wide open, but I was using the choke at that point instead
of squeezing the bulb. When it died, I thought I may have
choked it out too much. At that point, I decided I need
to tear into it to check a few things. Hard to see much on the
carb what’s going on with the air box in the way, so I need
to dig into it, check linkage’s travel, fuel filters, etc.
Perhaps the old fuel pump is toast.
Thanks.

Fleetwin, I will, if I get the energy about to heft that heavy bugger
into the test barrel.

I had checked this engine for spark prior, and it seem to be good.
I didn’t have any correct spark plugs, but ordered some.
Put them in today, and it appears that it’s going to “wind up”.
Amazing that it idled as good as it did before on one cylinder.
Motor is now on the boat, and awaiting a test run tomorrow.

I adjusted the low speed needle initial setting to 7/8 turn as suggested, but
think I now have it around 1/2 turn open. Will see where it
ends up after running it on the lake.

This 1975 has no thermostat, and the tell-tale pumps water
as soon as it starts. I’m guessing the later models with thermostats
didn’t foul spark plugs as bad?

After the video, I ran it again with the tank down lower on a stool,
and it seem to run okay with no fuel problems, with the cap loose,
and tight.

How are the caps on these plastic gas tanks suppose to vent or relieve
pressure? The tank was sitting in the sun prior to running the motor,
and appeared to be “bulging”. I cracked the cap and it had a lot of built
up pressure. I see no vent hole in the cap. How do they work????

VIDEO———–
https://youtu.be/5nxe_TBTGQY

Perhaps the powerhead was replaced with an older version without
a thermostat. Not sure if the core plug on these were stamped with
the model number? Anyway, not my motor, so I won’t worry about it.

fleetwin wrote:

These things definitely have thermostats, and I would absolutely replace it if it is missing.  Won’t idle worth a darn without warming up and will foul plugs.

Be careful, there are two different styles of heads you might find on this thing, each has its own unique gasket.  Post a picture of the head and I will get you the gasket part number.   These thermostats are a pain to replace, but it can be done, am guessing this has not been used in salt water.

I watched the video, seemed to run OK, your mixture adjustment seems right.

Fleetwin, I guess I better look at the parts diagram, as I didn’t
see anything atop the head or block that looked to be hiding
a thermostat. Thanks!

P.S.- What do you know about those plastic gas tank cap’s
venting or pressure relief systems?