Um...You did remove and clean the battery cables terminals, didn't you?

Are you sure the problem isn't in the (+) and (-) power supply wires to the tach? Is it a plug-in tach? Check the plug connections for corrosion.

Did I answer this question somewhere on another forum? Anyhoo, flywheel magnets made since WWII simply don't go bad.

Well no wonder you are having trouble. The round plate goes in the black pump housing then the circular piece, then impeller. In other words, it is a wear plate above the impeller, just as the...

If the diaphragm were holed you wouldn't be able to pump the primer up hard because gas would go through the hole and into the crankcase.

With great respect, I submit that that is not quite correct. When thermostat is closed, water pressure pushes the check valve open and water returns to the pump for recirculation. When thermostat...

I've never seen one blocked, even here in salt water country. Of course it's had 50 years to crud up.

Good. They weren't made for bucket cruising.
Make sure all the parts are in the thermostat. A bit of back pressure from the therm parts helps ensure complete filling of the block. Running it with...

Where are you running this motor, in a bucket, or??

You didn't disconnect the shift rod, did you?

EDIT: Oops, it slides down a foot? Doesn't sound right.

Old coot here (85). Outboard flywheel magnets made since WWII simply don't go bad, short of running them through the smelter. Look for something else.

It is a drain hole for the drive shaft isolation tube, and necessary. Don't be plugging it.

Blubber hole??? whazzat??

You get the transom mount kit right here at marineengine. Page 145 of the Seastar Solutions catalog, which you can also see here. (SeaStar used to be Teleflex)
SeaStar Solutions® Marine Catalog...

After reading through this long tale of woe, post #32 finally grabbed my attention. A clean piston is a sign that it might be ingesting water into the cylinder, "steam-cleaning" the piston. I'm...

"Antiques" are pre-1949, generally are non-shifting, and cast iron powerheads

According to the Antique Outboard Club's rules, an outboard over30 years old is a "Classic".

# 31 shift shaft through #7 are the other parts I suggested. #18 clevis might be broken is another possibility. Powerhead removal is necessary to inspect any of it. #18 can be replaced without...

IF our diagnosis from afar is correct, #30 would be the culprit. #17 C-ring holds it in. Powerhead removal is not necessary for this part, but it is somewhat of a PITA to access

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See post #3. Is there any jiggle at all at the shifter lever? If not, that likely is where it is seized. But if no jiggle at all, it probably is seized there the shaft goes through the housing. ...