1966 Johnson Outboard Runs great with rabbit ears on but won't run in the water?

I guess this is a 60 or 65 HP motor?

Very common. because you have underwater exhaust, which puts a load on the engine when the prop is submerged, while in the driveway it's completely unloaded. It'll easily run on two cylinders, maybe even one.

Before you spend any money, take a few minutes to do some basic tests, that way you only have to fix what's broke.

Compression test: no sense spending time or money on an engine with bad compression. Should be about the same on all cylinders (within 5% or 7%).

Spark test, not a *spark plug* test. You're testing the ability of the ignition system to deliver a spark to the plugs. Get an inline tester (couple bucks at a car parts store), set the gap for 1/4", clip it to the engine block, attach the plug leads (one at a time) and watch for a strong blue spark when you turn the engine over. Get bad or no spark on one or more cylinders, you'll have to troubleshoot the ignition system.

If you have good compression and good spark, on all three, make sure you've got fresh 87-octane fuel mixed 50:1 with TCW-3 certified oil. Make sure the primer bulb gets and stays firm when you pump it up. Make sure the the choke plates all close completely when the choke is activated.

All this and still no go, rebuild the carbs with new kits. Soak the metal parts overnight in carb cleaner.

Compression, spark and fuel, she oughta run.

distinction between the hose and interior the lake is backpressure on the underwater exhaust. did those factors-changers down on the boat place do a compression attempt and spark attempt? If no longer, try this first. Compression must be regarding the comparable on all 4. something over ninety could be sturdy on that classic v4. Spark ought to bounce a 7/sixteen" hollow on an inline tester. Is the primer bulb getting no longer effortless and staying no longer effortless? Take the airbox cover off. Are the chokes remaining off thoroughly once you turn on the electrical powered choke? Tilt the motor finished up and pump the primer bulb until organization. Does any gasoline leak out the carb throats? Are the spark plugs moist or dry after cranking? Are they champion QL77JC4 gapped at .030? Is the battery totally charged? it needs to crank a minimum of 250 RPM to initiate.

Are you running in the driveway with the cover off?

If so check where your fuel lines are when the cover is put on. You could easily be pinching a fuel line when the cover is on and put in the water.

You say that the spark plugs are wet which means the needle

and seat in your carbs are stuck open.Try cleaning them and

install new spark plugs and then run it again.Good luck.

cheapest thing to do 1st is install new spark plugs