Durbans refaceing exhaust box gasket faces 1974 70HP JOHNSON

durban

Master Chief Petty Officer
Joined
May 27, 2011
Messages
894
after some years your gasket faces look like this in the photo ,note the grey areas on the gasket face caused by corrosion & around the exhaust ports that's were water gets in causing all the damage . if you don't have a milling machine do this. get a rule & line it up with the edge ,were the 300mm & 100mm show on the rule scribe a line , then if you good with a small grinder grind the ridge that sticks out above the gasket face away the green wire shows where the ridge is .bare in mind the line you scribed grind up to those lines & flush with the gasket face . i use a 0.8mm cutting disc to grid it , it gives a better grind & smoother ,
then get a thick glass *& course grinding paste ,the water based one works better , then grind until all those grey areas go away . grind in circular & figure 8 motions .after grinding place the steel rule across the gasket face in a few areas to make sure its 100% .

you will end up with with a good motor that will go for another 40years if looked after do the manifold plate & the xhaust box
 

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durban

Master Chief Petty Officer
Joined
May 27, 2011
Messages
894
Re: Durbans refaceing exhaust box gasket faces 1974 70HP JOHNSON

manifold & exhaust box have been done & i also did the cylinder head & block , ive done a great improvement on this motor regarding the water flow & solved the reason as to why the water gets into the xhaust port , follow the thread regarding the conversion ive done on this block my epoxy coating works , try it
 

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