1992 Johnson 70hp Overheated, sand in motor

[Silverado6x6]

I have a 70hp Johnson with a jet pump, boat got into the sand real heavy and pumped all the cooling passages full of sand, I pulled the WP to check it was fine, did a compression test 117, 120, 123 pulled the T-stat, it was full of sand and melted together, over heat sensor melted the retaining plug, pulled head, pistons look OK, no scoring, head appears flat.

removed a LOT of sand from water passages, put motor together and now it won't start unless I ether it, will idle fairly but won't rev up, and interestingly the ign switch won't shut the motor off now, could the overheating caused something electronic to fuse? I'm thinking the stator under the flywheel as the upper part of engine was the hottest, and suggestions? Or could it be the spark box, I'm a diesel mechanic by trade but not so learned on outboard motors, thanks from anyone for ideas.

 

[tashasdaddy]

Re: 1992 Johnson 70hp Overheated, sand in motor

i would look for a melted black wire with a yellow tracer, that is the kill wire. i would check spark on all 3 cylinders. give us results.

 

[Silverado6x6]

Re: 1992 Johnson 70hp Overheated, sand in motor

I pulled the flywheel off this morning and the inner stator I guess its called had a section of what looked like melted plastic, I think it could be a problem.

The owner of the boat my employer says just put everything back together and he will take it to an outboard repair shop.

Fine by me though I did want to learn more about them. I have an abandoned Mercury 175hp outboard thats been in storage on our property for over 10 years, I know the owner, he gave up trying to maintain a woody hull boat also and gave it away, gave me a generator years ago and I am going to ask him to donate that Mercury to me, looks like everything is there on it, a V6 I think.