Logo
FULL SITE MENU

2006 johnson 150 primer bulb

S

sammi

Regular Contributor
This is the first outboard motor I've had in 30 years. I dropped the boat in the water for the first time and it had trouble starting. The primer bulb appeared to be pumping gas but it never got completely hard. It finally started and ran great. We went for a 20 min run then ate lunch. I started the motor and it fired up immediately then died in about 5 seconds. The primer bulb was soft so i pumped a few times but it never got hars. Is it supposed to be hard to the point it cant move?
 
When carburetors are full the float valves close and the primer bulb should go hard.----------When a motor is running you can usually give the bulb one squeeze and it should be hard again.----------------So if it does not go hard you might have bad check valves in the bulb.---Or leaking float valves in carburetors .--------Or a defective diaphragm in the fuel pump.
 
I thought that is what i was doing. Just trying to rule out your differential diagnosis. I also read the primer bulb should be tipped upright when priming. I didnt do that. Almost seems to simple though.
 
The primer bulb has an inlet check valve and an outlet check valve.-----Extremely simple and all it does is move fuel into the carburetors for starting.----It just saves the starter motor doing that.--Or in the case of a manual start motor it saves your arm from pulling on the recoil to fill the carburetors.---I have never found that it needs to be tipped " upright" in some 40 years of working on motors.
 
Well, i would not have believed it if i didnt try it myself. I got home from work and tipped it up and within 2 pumps it was hard as a rock! I dont know. Maybe it is on its last legs. I did an internet search and 5 or 6 post mention to do that.
 
Yes it works better if vertical. But it does go soft after the engine starts. It should pump up and be very firm before start. If it doesn't, there is a fuel leak somewhere after the bulb, or the bulb itself is defective.

The primer bulb is a very, very good diagnostic tool. If it never gets firm, fuel leak on engine side. If it sucks flat when running, fuel restriction. If engine stalls when running, and if you can pump it while running, and the engine keeps going, then look at fuel pump. Very handy tool.
 
Back
Top