89 Johnson 40hp - Idling Issues

[Caddis295]

Looking for some help with my Johnny.

Background: Rebuilt the carbs and removed VRO pump system. Installed two port fuel pump. New fuel lines and fuel bulb.

Fuel Bulb pumps firm and I can prime the motor at the throttle and the motor will turn over and will idle for a short time then die.

It will start and idle every time I prime the motor at the key but will die shortly after. I installed a clear fuel filter and you can see fuel in the filter. The level of fuel in the filter will often slowly trickle down as if it is being pulled back toward the tank.

I have the vent open on the fuel tank, and the fuel bulb is pointing in the right direction.

Please help me figure this problem out.


Caddis295

 

[jshane39]

Re: 89 Johnson 40hp - Idling Issues

I read something on this problem some time ago. People on this site suggested checking a valve that was between the fuel tank and engine that sometimes goes bad. Which would sometimes cause the fuel to be drawn back down towards the tank. I will check the archives to see if I can find out precisely what they were talking about.

 

[jshane39]

Re: 89 Johnson 40hp - Idling Issues

Anti-siphon valve (posted in archives)

Anti-siphon valves are USCG required fitting to prevent fuel from being siphoned from built-in tanks in the event of a break in the fuel line.

They are usually located at the top of the pickup tube on the outgoing fuel fitting and generally consist of a spring-loaded steel ball inside the fitting. If none of the the fuel line system is below the level of the top of the tank, they can legally be removed.

Because of their design they are easily clogged. Also, older ones were not designed for ethanol.

 

[Caddis295]

Re: 89 Johnson 40hp - Idling Issues

Thanks for the info,

Unfortunately, both the fuel tank and the fuel line to the motor are brand new.



Caddis295

 

[jshane39]

Re: 89 Johnson 40hp - Idling Issues

Will it continue to run if you pump the primer bulb while the engine is running?