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external fuel-line flow

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Swiftsailor

New member
I have an '05 Tohatsu 4hp 4-stroke that won't run consistently from an external tank. The tank is a standard portable marine tank with a standard fuel line/squeeze bulb. I have to keep squeezing fuel into the motor's tank for it to keep running.

It's an older tank (5/8" line I believe) and I have already replaced the connector with a Nissan/Tohatsu connector to be sure it had the correct flow rate.

The motor runs consistently with fuel in the internal tank.

Any ideas?
 
I thought it was the venting, too. Made sure both vents were open (tank/motor) and also replaced the bulb with a new one. Still, it stalls if fuel is not forced through the line. This occurred as soon as I started using it, right out of the box, but as I said it runs fine with gas in the motor's tank.
 
You are either not getting fuel, or you are drawing air. In order to isolate the internal tank (and run on the external one), you must close the fuel cock. If not, and the internal tank is empty, you can draw air from the internal tank. Or... it's possible that the fuel pump is not working well (or the check valve is restricting flow), and the pump can't draw well enough. This wouldn't affect the internal tank supply, since the most of internal tank is above the carb, and the fuel can flow by gravity.
 
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