1966 Johnson 3HP running Hot JW21

[fishon71]

Checked water pump looks good.<br />Checked water tube looks good.<br />Head seems extremely hot in 2-3 minutes running in tank and smells hot as well.<br />Should it spit water out from some where, I see none? <br /><br />Only other thing I can think of is pull head and inspect for clogged water ports, ya?<br /><br /> <br /><br />Thanks Bill

 

[Paul Moir]

Re: 1966 Johnson 3HP running Hot JW21

Heat should get extremely hot. The cooling passages in it are terrible. Put a little drop of water on the top of the head. If it sizzles, you've got a problem. If it just evaporates, it's fine.<br /><br />Best place to feel is the top of the block, or better yet the side of the cylinders over on the (starboard) intake side - those should be luke-warm. Watch out for the flat plate on the port side - that gets hotter than the head!<br /><br />Water mist should come out through the idle exhaust relief half-way up the leg. Put your hand over it and it should get wet. You can also pull the flush port at the base of the handle (I think it was still there in '66) and see if water comes out from there. Don't run it with the flush plug out though!<br /><br />Good luck!

 

[fishon71]

Re: 1966 Johnson 3HP running Hot JW21

Pulled head & cleaned water passages, new gasket and she is all better now, ran for an hour no problem!

 

[Paul Moir]

Re: 1966 Johnson 3HP running Hot JW21

<br />There's some nasty spots where that block can clog. <br />PS - run with more oil than OMC specified. 32:1 or even 24:1.