TOPIC: Fuel Pump Problem

Heres the deal, 1967 80HP Evinrude, runs fine until WOT then it cuts out and dies unless you pump the bulb. Points to the fuel pump, rebuilt it and it's still doing the exact same thing. Thought it might be that cheapo attwood gas tank, switched to my grandpa's metal OMC tank that he uses with his 40 horse Johnson, still did the same thing. The fuel line and bulb works fine with my 25HP Gale. So its gotta be the fuel pump. What could be causing this thing not to work? I took the pressure line off and the block is giving plenty of pressure out of the hole. Is there a set size fuel line running from the carb to the pump I'm supposed to use? I think I'm using 5/16"? Does anyone have a picture of these V4 fuel pumps taken apart? Thanks!

007,what kinda gas you running? non-ethanol? treated ethanol?I can get you a pic.jim

It does have ethanol. I know it's a no-no, but I run non-ethanol in my Jetski, and I've just been trying to debug all the problems with this motor before I go the literal extra mile or so to get the no-ethanol gas. The motor run's flawless when the bulb is pumped every 5-10 seconds at WOT. Looks like this one:

La007 wrote:

The fuel line and bulb works fine with my 25HP Gale. So its gotta be the fuel pump.

Is there a set size fuel line running from the carb to the pump I'm supposed to use? I think I'm using 5/16"?

The 25 Gale uses about 30% of the fuel the V4 uses. You still can't discount the fuel line. Those Attwood lines are junk, just like I said before. That fuel pump is sucking, not pushing, any flow restictions will be amplified.

As for the fuel line, the size of the nipple will dictate the size of the line but I would think it will be 5/16th.

check all the fuel lines on the motor it self.Also one big thing the float in the carb. If set to low it will run out of gas.
Mike aka the pirate

It help's to not invert #13 and #25 when putting the fuel pump back together, ALWAYS check parts diagrams. This is what I found to have done wrong. It's always human error..