2003 115 Johnson problem. - The Hull Truth

2swift · 10-23-2007, 09:21 AM

I will do my best to explain.
Seems to run fine at ideal in and out of gear and at lower rpm's.
Went out Sunday and as soon as I got up to about 4300 rpm it bogged down and then powered back up and bogged down sporadically. Lower rpm to around 2500 rpm and ran better but still farted every ounce in a while.
Here's the thing at the end of the day we arrange for someone to follow us in and leave earlier then normal incase we need to be towed in and the Damn thing runs perfect with no hick ups! What gives?

2swift · 10-23-2007, 07:47 PM

Forgot to add this is a 2stroke.

A1 Outboard · 10-31-2007, 08:41 PM

Your description of bogging down then powering up again, over and over again, sounds like a fuel starvation problem that is causing the surging. The most common problem is either air leaking into the fuel system or there is a restriction somewhere.

Visually inspect the hoses for any soft spots, kinks, sharp bends, etc.

The quickest test is to use a vacuum gauge at the fuel pump inlet and a length of clear fuel line. Run the motor at the surging rpm and look for air bubbles in the clear fuel line or for more than 4" of vacuum restriction. You then troubleshoot from there. Good luck.

2swift · 04-30-2008, 12:21 AM

Quote:

A1 Outboard - 10/31/2007 10:41 PM

Your description of bogging down then powering up again, over and over again, sounds like a fuel starvation problem that is causing the surging. The most common problem is either air leaking into the fuel system or there is a restriction somewhere.

Visually inspect the hoses for any soft spots, kinks, sharp bends, etc.

The quickest test is to use a vacuum gauge at the fuel pump inlet and a length of clear fuel line. Run the motor at the surging rpm and look for air bubbles in the clear fuel line or for more than 4" of vacuum restriction. You then troubleshoot from there. Good luck.

Just a very late FYI The problem was the power pack.