Fuel Coming "Through" Pump

[Liquidathlete]

I just rebuilt my fuel pumps and carbs, after priming and trying to start, I realized that I had fuel ALL over my engine compartment. After having someone crank the motor, I noticed that the fuel is coming through the small hole on the back of the fuel pump. As far as I can tell, this hole is to allow the crankcase pressure through so that the diaphrams work with/against each other.

My problem is that I have fuel pulsing through the hole in the back. WHY?

 

[Theoutdoorsman]

Re: Fuel Coming "Through" Pump

Not sure what your working on???? No model number posted. Maybe this will help.......

http://forums.iboats.com/showthread.php?t=240864


BTW......... Welcome to iBoats!!!! ....................... ALAN

 

[Liquidathlete]

Re: Fuel Coming "Through" Pump

The motor is a 1976 Johnson 200. It has the high performance fuel pumps on it.

It's very similar to that fuel pump, but it has another port in the bottom that is connected to the crankcase, I am not sure it fuel is coming from the crankcase. If so, what would cause that. I have the shop manual, has nothing about it in there. I looked through the whole fuel system section, and the whole crankcase section. It just doesn't specify.

I have read through here that the pump works off vacuum, if so, I DEFINITELY shouldn't have fuel traveling from the crankcase to the fuel pump.



I did use that thread when rebuilding the pump, very helpful.

 

[Liquidathlete]

Re: Fuel Coming "Through" Pump

Does anyone have a plumbing diagram on this pump/fuel system?