Plumbing/ cooling

[W. A. Fipps Jr.]

I have a 1976 Johnson 25 hp 2cyl, motor runs like a champ, one problem, no water circulation, water pump is in very good shape, I suspect an obstruction of some type some place at the upper end just prior to discharge, I need some guidance as to plumbing layout! Any help or source for a schematic would be a great help. Thanks Much

 

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Re: Plumbing/ cooling

Welcome to iboats, ChessNut. You can use a coat hanger to run up the discharge to see if it is clogged.<br />Remove the thermostat (sorry, I don't have a manual,so cant say where to look), probably close to the top of the cylinder head.<br />If you can't knock it loose,and the thermostat is ok, Remove the t-stat again, and spray an entire 12 oz can of WD40 into the block at the t-stat housing..Let it sit for an hour or so, put it back together,and try it. If you still can't get anything thru it, you may have to pull the heads and clean the white stuff out of the ports.<br />This may be risky,as head bolts like to break.