1967 Johnson 60HP top speed issue

[RickyAust]

I took my 1967 Johnson 60HP out today on my 13.5 fiberglass runabout. It had been about 4months since it was last out and there was appx 1/2 tank of 4month old fuel in the tank still. I filled the remainder up with fresh fuel/oil mix. Started well, however it seemed to really struggle and bottom out when I tried to plane out at high speed. After about 30secs of really struggling and bottoming out it picked up speed and got up to 30mph. Afte I slowed down again and tried to speed up same again, took quite sometime before it reached top speed. We put someone behind the boat on a tube and it really laboured for sometime and struggled before it picked up all of a sudden. Could this be due to the old fuel still being in the tank?

 

[tashasdaddy]

Re: 1967 Johnson 60HP top speed issue

actually sounds like a dirty carb. the boat sitting 4 months, the gas in the carb has evaporated, and varnished up the carbs. especially the high speed jet. also check you spark, could have a coil failing, but i doubt it.

 

[grid]

Re: 1967 Johnson 60HP top speed issue

The 60 had adjustable high-speed jets. If one is blocked with gum, you can compensate by turning it counter-clockwise an 1/4 turn until some of the crud passes. You should be using a stabilizer in the fuel, and fuel injector cleaner wouldn't hurt, either. Do you have a "Cruise-a-Day" gas tank? Back then, days were measured in nano-seconds as far as OMC was concerned. On an 18' runabout, the 60 burned about 32gph WOT..lots of fun changing tanks just before they drew empty!

 

[tashasdaddy]

Re: 1967 Johnson 60HP top speed issue

do it right clean and rebuild the carbs, then keep seafoam and stabilizer in your fuel. why take a chance of running lean and your motor croaking.

 

[Texasmark]

Re: 1967 Johnson 60HP top speed issue

Hey grid, note your humor....or lack thereof. Grin

As I recall that was the year before the 3 cyl looper came out. No doubt things changed, surely for the better.

Mark

 

[jimmbo]

Re: 1967 Johnson 60HP top speed issue

The 60 had adjustable high-speed jets.

OMC switched to fixed high speed jets in 1961. They didn't release a 60hp as an Evinrude or Johnson until 64. However the Gale division had released a 60hp in 1960, that one would have had adjustable high speed jets