soft bulb

patrick4266

Chief Petty Officer
Joined
Nov 29, 2007
Messages
591
I have a 1972- 85hp rude. I took the carbs off my 1970- 85 hp rude because it would not run right. It starts fine but will only rev up for a min then it acts like it is starving for gas. Thats the reason I changed the carbs in the first place. Anyway I can never get the bulb to pump up firm, Do you think that is the problem or is it the fuel pump?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: soft bulb

Does the bulb get sucked flat or just stay soft? If you can't get the bulb to firm up before you start the engine, either it is defective or there is a float problem in the carb. The bulb pumps fuel into the float bowl on the carb until the float rises and shuts off fuel flow. At that point the bulb should be firm. Once you start the engine the bulb will go soft again because fuel is being sucked through it. There is not pressure in the line to keep it firm. That's normal. So start the engine and squeeze the bulb when the engine begins to die. If it picks up again, you have a bad fuel pump.
 

Evinrude Boater

Lieutenant Junior Grade
Joined
Jul 6, 2004
Messages
1,144
Re: soft bulb

When it starts to act like its starving for gas did you pump the bulb or spray fuel into the carb? If it runs better you'll know it's starving for fuel. Then you can trace back from there.
Did you disassemble, clean and blow out the orifices with compressed air. A little speck in the main jet can keep the main jet open and you'll just keep pumping gas through the carb into the engine.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: soft bulb

I have two primer bulbs in my boat and neither one of them will ever pump up firm. That's the way they have always been. Someday I'm going to tear one of them apart to see just what kind of crummy check valves they have in there.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: soft bulb

either float needle not closing. or if using after market bulb, hold bulb vertical, with arrow pointing up, they work better that way. are the plugs wet. if so fuel pump diaphram may have a pin hole in it. leaking into the crank case, flooding the motor.
 

patrick4266

Chief Petty Officer
Joined
Nov 29, 2007
Messages
591
Re: soft bulb

I really do not think it is the carbs as they worked fine on the other motor. I did notice that when i cranked the motor, with the plugs out, there was a lot of gas mist still comming out of the plug holes. I will take the line and bulb out of the other motor and try that first,if that does not work , then I will try the fuel pump.
 
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