Reply To: 1972 85 hp V4 water circulation?

[Don]

Well, usually the tap for the telltale on these engines is located on the exhaust cover, which is at the beginning of the cooling cycle. But, your exhaust cover does not have a provision for this…Plus, your engine has that return check valve, so not too sure what pressure values you might see. Water pressure gages were introduced for later model engines with the single tube cooling system..
I think you are correct in putting the engine/boat in the water and trying it out, that way you can monitor your telltale. Once the initial air has bled out of the block, you should not see any air or steam spurts….Does your control box have an overheat warning horn? If so, have you checked to see if it is operational? This is another good way of monitoring engine temp. Unfortunately, these things can overheat in an instant, oftentimes you won’t have a chance to see the loss of pressure from the telltale, and the warning horn comes on as the engine is seizing up when overheating occurs at high speeds….
So, I would give it a trial run on the water, have an assistant drive while you monitor the telltale to catch an issue before it overheats badly.