1974 Johnson 15hp Restore

[taylorman]

I am restoring the above motor and have a couple of questions. I want to replace the reed valves with boyensen reeds. I know that in the later model 15hp's had a spacer between the reeds and stops to allow the reed to open more. Would this offer any advantage with the boyensen reeds? Another change that was made was with the inner exhuast tube. Would it be worth it to change out my exhuast tube with the newer tuned rounded tube while I have it broke down. Thanks.

 

[bktheking]

Re: 1974 Johnson 15hp Restore

The reed spacers had nothing to do with power increase and everything to do with better throttle response. If you are going to do the conversion put the tuned exhaust in it, it's more than just a carb as OMC demonstrated with the change to the later models. Do the spacers as well, it wasn't just the 15 that got them, the 9.9did as well.