45 HP Mariner (classic 50) overhating again

sjoefl01

Seaman
Joined
Oct 17, 2012
Messages
69
I have been fighting this for a long time. The engine has a good stream when it idles but when I take off it stops and steam starts coming out with little bursts of water. When you drop back to idle the stream increases and cools down. The first time I went after this was about a year ago. Of course I have changed the water pump several times. That is not he problem. The first time I took off the exhaust cover and blew out all the water passages. That cleared the problem and the engine ran and cooled perfectly for a year or 2. Now it has started it again. Same as before we changed a perfectly good pump and blew out the water passages behind the exhaust cover. That didn't help at all. The first time I had a shop tell me this happens frequently with a cracked exhaust plate. Of course we blew air through the tell tale and that path. There is nothing blocking it. We can't get the cover that the plugs screw into off without breaking the bolts. We were discouraged from continuing that course. I think we are going to pull the power head and examine the exhaust plate. Are there any other ideas or experience that might help? I have a crappy book. Does somebody have instructions to remove the power head? Any help will be appreciated. We are just a step away from the junk yard.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,543
Work required but I would inspect the piece ( nla ) at the top of the watertube.------------Powerhead will need to come off.
 
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