Logo
FULL SITE MENU

1992 Johnson 150 bogs on acceleration

L

lvrtr

New member
1992 Johnson 150 J150EXENC. When put in the water, prime bulb, motor starts easily, idles smoothly, and takes off with no problems, and cruises at WOT very smoothly. When stop and shut down for a while, motor starts easily, and when put in gear will idle along. But when try to accelerate, it bogs down immediately, and will die unless throttle is pulled back immediately. If move the throttle forward and back many times quickly, before motor dies, it will eventually accelerate all at once, and cruise smoothly. Most of the time, if the primer bulb is squeezed when trying to accelerate, it will take off without bogging or dying. Primer bulb feels soft before starting (like it is losing it's prime?). Am I looking at an air leak in the fuel system?
 
Either the "Anti Siphon" valve at the built in gas tank... the fitting the fuel hose is attached to, is sticking in the open position or doesn't exist. Instead of the valve, the center components may have been discarded which creates a straight thru fitting.

This fitting/valve is always lower than the engine and if stuck open or missing, the fuel can easily siphon backwards into the tank. The fact that pumping the fuel primer bulb corrects the problem proves this point.

The reason your engine may have run fine in the past would be due to exceptional sealing of the fuel primer bulb valves.... those plastic valves don't last forever.
 
Thank you for quick reply. Believe you are right. I removed the ball/spring from the anti-siphon valve about a month ago, as it was causing a fuel restriction to the Johnson 150, which replaced a Johnson 115. Have had the problem since then. Am going to look for a larger anti-siphon valve to put back on the tank.
 
lvrtr said:
Thank you for quick reply. Believe you are right. I removed the ball/spring from the anti-siphon valve about a month ago, as it was causing a fuel restriction to the Johnson 150, which replaced a Johnson 115. Have had the problem since then. Am going to look for a larger anti-siphon valve to put back on the tank.
Click to expand...

We had a hunch it was your fault! :)
 
Back
Top