1959 Johnson Issues

[deezelteck]

Well I have a 1959 johnson 35 Hp that really has me confused. Its a good running outboard, really moves my 14' 6 Lonestar. The trouble that I am having is after running the engine for about 5 min at WOT it will overheat (steam will be coming out and it quit running on me the first time this happened) I have run a compression test (100@100), replaced the head gasket, thermostat, check valve,and impeller. I have checked the water passages and all are clear. I have found that running at idle there is water coming out and it will not overheat, just at WOT its like the water quits flowing. Any help is appreciated.

 

[tashasdaddy]

Re: 1959 Johnson Issues

make sure the grommet between water tube and water pump is not pinched, it will restrict the water flow. also could be exhaust gasket.

 

[deezelteck]

Re: 1959 Johnson Issues

Wow, never thought about the exhaust gasket. As for the grommets I have checked them an they are good. Let me ask a question. If the exhaust cover gaskets are leaking or the inner plate has a hole, it is letting exhaust back into the engine, correct? This will make it blow steam and mess up water flow? The exhaust cover is the only part of the engine I have not had apart, and after reading the manual this is a must.

 

[tx1961whaler]

Re: 1959 Johnson Issues

Be very careful taking off the exhaust cover. The bolts sometimes like to break off.

 

[deezelteck]

Re: 1959 Johnson Issues

Ok, I have removed the exhaust cover and the plate. The gaskets look ok.. Not torn or anything. There was some corrosion places on the inner plate. How would the exhaust gaskets or plates cause the engine to overheat?