1967 Johnson 20 HP impeller?

[stykler]

Hey all..<br /><br />Bought a 1967 Johnson 20HP that had sat for 4 years. After an extensive carb cleaning, got it running. Water at one point was coming out the back, but then stoped, so I shut her down. Sounds like the impeller? What are your thoughts? How tough is replacement? Should exaust come out of the water holes as well? I noticed after shutting down, some exaust floated up from underneath the engine...anything to worry about? I didn't know if I should be worried about a possible blockage in the coolant system. If I drop the lower unit and try to force air through the system, will that give me a good indication? One more question, I take it that there is supposed to be a constant flow of water, correct? Is there a thermostat?<br /><br />Thanks,<br />Kelson Graber

 

[Waterbugtoo]

Re: 1967 Johnson 20 HP impeller?

Thats a lot of questions. After sitting for 4 years, besides the carb job, an impeller should be automatic on the list. The job is not too difficult. Change the impeller, and you should be good to go. You should get a steady spray (not stream) of water from the exhaust relief.<br /><br />

 

[steelespike]

Re: 1967 Johnson 20 HP impeller?

Stykler,You should have a service manual.<br />After market manuals are available at the library,<br />or the bottom of this page,NAPA auto parts,<br />Amazon.com ebay etc.If you have the bucks you can get reprints at www.kencook.com