Larger fuel hose

[Lowranger]

I have an '89 Johnson 70 and I would like to install a Navman 3100 fuel flow computer on my C-Dory. The Navman requires a 3/8" diameter fuel line for installation of the transducer. My entire fuel system uses 5/16" OMC hose. I could install a section of 3/8" using reducers on either side of the transducer but this would require extra splices (2?) that would increase the risk of air leaks into the fuel. Alternately, I could install 3/8" hose from the Racor fuel filter outlet to the coupler @ the engine and make just one splice. Is it acceptable to use the larger diameter fuel hose on my motor or does this create problems? Please advise me which approach I should take. Thank you, Pete

 

[Dhadley]

Re: Larger fuel hose

Every "slice" can cause a fuel restriction. While the 70 probably wont be affected, the best plan would be to replace a complete section of your existing 5/16" ID hose and put your sender in that section.<br /><br />While it most likely will not affect your motor, I would ask Navman what affect it will have on the readings since the instructions call for a complete 3/8" ID system. <br /><br />A complete 3/8" ID line system for your 70 can do no harm whatsoever.<br /><br />Good luck!

 

[Lowranger]

Re: Larger fuel hose

Dhadley, Navman said replacing the final "complete section" only with 3/8"(fuelfilter > motor) to accomodate the transducer is ok. I'll do that and leave the rest of my fuel lines(5/16") as they are. Thank you, Pete

 

[Dhadley]

Re: Larger fuel hose

Youre welcome. An interesting project. Let us know how you make out.<br /><br />Good luck!