Johnson 4HP 4STROKE

[Blake green]

I have a 2003 Johnson 4ph 4stroke engine and it has suddenly started playing up. In lower revs it moves along fine but when i open up the throttle a bit it revs ok but goes no faster, slower if anything. i would normally presume this had an incorrect prop however it is the orginal one.. its almost like a clutch slip or something... any idea people.. many thanks

 

[Rick.]

Re: Johnson 4HP 4STROKE

Probably a spun prop or broken drive pin. Pull the prop and see what things look like. Best of luck. Rick.

 

[Blake green]

Re: Johnson 4HP 4STROKE

Many thanks what do you mean by spun prop??

 

[Rick.]

Re: Johnson 4HP 4STROKE

Sorry for the delay. The prop has a center which is pressed into rubber which is pressed into the prop. A spun prop is when the system breaks down allowing the inner core to spin faster than the outer prop blades. Kind of like a stripped bolt. If you pull the prop and draw a line across the center then replace it and give it a good run, when you pull the prop again the lines should still match up. If they don't, you have a spun prop. Someone has a picture in a post somewhere you might try doing a search to find it. Rick.