6 HP Johnson overheating

[atticus3600s]

1968 6 horse johnson. After running at WOT the engine block is hot enough to burn you in less than 3 seconds. Water is coming out of the pee hole opening in a spray (as I was told it was supposed to)but that water is very hot also-you cant leave your hand trailing in it for very long. Carb. rebuilt last year, compression is 112 and 115 on cylinders 1 and 2 respectively, also I seem to having an intermittent spark problem on one of the cylinders as max RpM's cannot be reached.<br />If anyone has any ideas, they would be greatly appreciated.

 

[Blueclaw]

Re: 6 HP Johnson overheating

pull the flywheel and check the points for your spark problem.<br /><br />Have you checked the thermostat for the heat problem? When was the last time the water pump was serviced and was the intake screen checked?

 

[Joey One]

Re: 6 HP Johnson overheating

Water from the pee hole should come in a steady stream. This tells you that the water pump is working and cools the exhaust manifold. But it does not tell if water is getting to the cylinders and head. <br />Some water should spray out of holes in the upper rear of the exhaust housing. This tells you that at least some water is going through the cylinders and head. You should be able to hold your fingers on the head for 3 seconds.<br />Your description indicates that insufficient water is getting through the cylinders and head. Inspect the passages from the exhaust housing to the cylinders; then inspect and test the thermostat, if any; then remove the head and clean the water passages.

 

[Solittle]

Re: 6 HP Johnson overheating

Don't think the 68s had a pee hole.