2000 Hunter 310 Fuel Line

[Revere]

While changing the fuel hoses, I noticed there was no valve at the fuel tank for the return fuel. When I removed the hose from the barb at the engine, the fuel syphoned out of the fuel tank. Had to use a vice grip to stop the fuel from leaking. Would anyone suggest putting a valve on the return line for safety reasons? I know it must always be open.

The original hoses were 2 different sizes 5/16 on the engine and 1/4 leading from the tank to the engine. Don't know how they got the original 1/4" hose on the 5/16" engine barb. I couldn't do it. Changed all hoses to 5/16. Has anyone had this problem? I have a Yanmar 2GM20F.

 

[Don12364]

The return line must always be open or the engine might blow the hose apart should you forget to open the valve.
However many boats get round this potential hazard by returning it to the top of the tank and above the fuel level so that any entrained air does not cause foaming of the fuel.

 

[Revere]

Added Fuel Valve

I added a fuel valve to the return line. It will always be open except in emergency, ie the return fuel line gets cut. It was a good thing to do cause I also located the supply valve which was behind a partition.
Job is finished. Now trying to bleed the air from the ejectors.

 

[Paul F]

Instead of a valve you might put in a check valve or anti-siphon valve. I put one on the supply side as the engines injectors were higher than the tank and fuel was draining back off the injectors making starting hard or requiring bleeding. I put the anti-siphon after the primary filter ahead of an electric fuel pump that replaced the mechanical one on the engine. The return fuel line after the injectors is routed above the engine and into the fuel tank's air vent. This fuel line system seems to work well and was suggested by diesel mechanics.