1973 25hp Johnson

[sogafishin]

I put together 1973 25HP Johnson for my fishing boat.Took it out today for the first time and it cranked right up.Run great low end picked the boat up planes out and started surging and shut off hit the starter and it spun over a little bit and fired right up again but wouldnt take off.I held the bulb in my hand and squeezed it as it was running and she runs like a champ.It will run forever under 1/2 throttle without grabbing the bulb but if I gas it to go I have to keep pressure on the bulb to keep it from surging.I know its a fuel problem but is it the fuel pump or the carb?Seems like if it was the fuel pump it would run out of fuel even at slower speeds.Could the float level be too low and me squeezing the bulb push the fuel in it needs?thanks

 

[14ftgrumman]

Re: 1973 25hp Johnson

Check the float level, but it sounds like it could be fuel pump.

Is the bulb hooked up with the arrow pointing to the engine? Ad how old is it. Possible cracked hose or loose coupler and it's sucking air? Does have the "lean sneeze"?

 

[k dogg]

Re: 1973 25hp Johnson

you have the fuel tank vented ?

 

[sogafishin]

Re: 1973 25hp Johnson

Yes it does have a little lean sneaze at idle opened the low speed and it stopped vent is open.Im going to tkae the carb off and check the float level tomorrow.

 

[samo_ott]

Re: 1973 25hp Johnson

Sounds like fuel pump issue to me.

 

[restornator]

Re: 1973 25hp Johnson

its not the carb, i guarantee it. It's either a leaky fuel connection or a pitted diaphragm in the fuel pump.