1989 Johnson 28 SPL Sputter at WOT

[mrloring]

I recently changed the prop on my 1989 Johnson 28 SPL to reach higher rpm's. I was barely able to reach 4000 rpm's before the new prop. First trip out it ran so much better with the new prop, but when I reach 5000 rpm's it starts to sputter(like it is cutting out). At first I thought that it might be a ventilation problem but the rpm's do not rise when it happens. If I back off the throttle a little it does not do this. <br />Any ideas what is causing this?

 

[JB]

Re: 1989 Johnson 28 SPL Sputter at WOT

If the sputter is "4 cycling" it is caused by a very slightly too rich mixture, mrloring.<br /><br />"4 cycling" is a very regular firing on alternate power strokes.<br /><br />It can be caused by a too high float setting or by misadjustment of adjustable mixture.<br /><br />If what you are getting is not regular 4 cycling but intermittent misfire I would do a very careful link 'n' synch and clean and gap or replace the plugs.<br /><br />Good luck, and let us know what you find.