1999 Johnson 225 hp fuel problem????

[adm1476]

I have a 1999 225 johnson that seems to run out of fuel when idling. I have rebuilt the fuel/ oil pump with all new parts. The oil part of this pump has been disabled so it is only being used to pump fuel. After pumping the ball up until firm the motor will start and idle for several minutes before stalling out. Then the ball needs to be pumped up again at least 7 - 10 pumps to fill everything back up with fuel. Then it will restart and idle again for several minutes. The ball is new, the pump is completely rebuilt, and the fuel filter is new, also the fuel line to the filter is new. What could be causing this????

 

[jakedaawg]

Try taking the output line off the fuel pump, crank engine and see if a ton of fuel spits out. That would be a simple place to start without hooking up a bunch of guages and clear hose and whatnot. Do it with the safety lanyard pulled off so no spark. This will confirm the pump actually pumps.

 

[racerone]

A positve pressure pulse and a slight negative pulse operate the pump.----So you need to check for crankcase compression.

 

[adm1476]

Jakedawg I will try that today.
Racerone How do you check for crankcase compression, and what should it be at?

 

[jakedaawg]

any luck?

 

[adm1476]

I tried that and when the system is full from me pumping the ball it squirts fine while cranking. Just a note the boat runs fine at cruising speed, but has a hesitation of the start. Also like I said it only will idle for several minutes then it runs out of fuel.