1966 won't pump water

I’m working on a 1966 20 hp tiller steer Johnson. I changed plugs, lower gear oil (there was nothing but water), and the impeller. The motor fires and sounds really strong. But there is no cooling water.

I am pretty sure I got the pick-up tube in the grommet and everything else looks fine. Any ideas on what to do next. Besides dropping the unit and reinstalling impeller. Does it matter which way the impeller tines are bent in installation.

Jim

Re: 1966 won't pump water

when installing you impeller, your motor runs in a clockwise direction looking from the top, when you install the impeller turn the drive shaft clockwise from the top. sound like you need new seal in the lower unit to keep the water out.

Re: 1966 won't pump water

A new impeller is nice and supple and the vanes will "right" themselves if you get them wrong. But it's a very good idea to get them facing the right way the first time.
Take the cover off the thermostat housing (on top of the cylinder head). Take out the thermostat. Start the motor in a barrel of water. You should get a fountain gushing out of the open thermostat cover. If you don't, the waterpump ain't pumping water. If you do get a fountain of water, then the thermostat is plugging up the works or there's something blocking the powerhead water passages (like a broken chunk of old dry impeller). You can sorta check the water passage in the powerhead by forcing air into the opening with an air hose and listening to hear if it exist the lower unit. You want a new thermostat anyway.

Re: 1966 won't pump water

Finally got back. The thermostat had never been changed judging from the paint on the gasket. I put the cap back on without the thermostat and no water. Tomorrow I drop the bottom again and make sure I got the copper tube in the grommet.

If I force the air is there a problem with too much pressure. And I force the air down through the water jacket and out the exhaust jacket.

Jim