Have a 75 hp Johnson from 83/84 that showed 7, 7.2 and 7.5 bar (100-108 PSI) in a compression test. From what I've read, these must be around 8-9 bar (120-130 PSI) optimally. I wonder what this engine miss of effeckt wear-wise.
Re: Performance of 75 Johnson with low compression?
Older motors have lower compression, I think what is key though, is that all the cylinders are within 10% of each other, I would suspect the motor to run ok-good...
Re: Performance of 75 Johnson with low compression?
its a 30ish year old motor, those comp numbers are looking good . not sure what you meant by the last sentence in your post, but you would barely notice any performance gains from what you have... to what you want.
