High speed problems. 85hp 1972 johnson

[Shifty1973]

I recently purchased a 16 ft aluminum Starcraft with a 85 hp Johnson 1972. It starts and runs halfway decent but when I am at full throttle I am not getting anywhere near the speed I should. Can anybody help?

 

[boobie]

Re: High speed problems. 85hp 1972 johnson

Start with a compression test and spark test on an open air gap spark tester. Spark should jump a 3/8 " open air gap.