Fuel Line 3/8" vs. 5/16"

[Greenporter]

2006 90hp with a portable tank.

The manual says to use a 5/16" fuel line for 25hp-130hp. My boat has a 3/8" fuel line for some reason - I guess they made a mistake when they installed the engine. I have owned it for 2 years and it has run flawlessly. I came across the fuel line problem this week while troubleshooting a warm starting problem. Cold starts and runs perfectly but after an hour of sitting it take 10+ key turns to start. Someone suggested I stop pumping the ball (and choking) before starting it after the hour.

I don't think the fuel line size is related to the issue but I wanted to know the forums opinion of the suggested 5/16" vs. the 3/8" I have been using.

 

[Daviet]

Re: Fuel Line 3/8" vs. 5/16"

I would stick with the 3/8 fuel line.

 

[emdsapmgr]

Re: Fuel Line 3/8" vs. 5/16"

The size of the fuel line is unrelated to any problem. Your engine will run fine on either 5/16 or 3/8 line. If you had a V6, the 3/8 line would be required. Unlikely you should need to reprime the fuel hose bulb during the same day of operation. You may only need to re-choke the engine when it cools off, usually after a few hours.

 

[Greenporter]

Re: Fuel Line 3/8" vs. 5/16"

Two votes for keeping the 3/8" is good enough for me.

How about pumping the ball until stiff on an engine that has been running for awhile then sits for an hour? From what I understand it shouldn't matter if I pump it again since the carb floats will keep out the gas.

 

[Greenporter]

Re: Fuel Line 3/8" vs. 5/16"

just read your response about the ball pumping.

thanks - I think I will lay off the choking and pumping on the restart after the hour long sit. Hoping this will solve the problem.

 

[Rick.]

Re: Fuel Line 3/8" vs. 5/16"

I can't see a reason why it would hurt anything. On the other hand it is probably not necessary after just one hour. I think it is one of those things that you have to learn what is best for your motor. I don't pump my bulb (85-40 HP. Johnson) at all during the day after the initial cold start and that works well for me. My little motors (15 and under) do seem to require a bulb pumping after sitting for a while during the day but don't normally require choke after the initial cold start. I too agree there is nothing wrong with 3/8 fuel lines even if 5/16ths. is good enough. Rick.

 

[Seth1904]

Re: Fuel Line 3/8" vs. 5/16"

i would have to agree witht he fuel line i would stick with the 3/8's line it sounds like it has to do with the carbs