Thickness of fuel line for Yamaha 9.9 kicker

DollarBoat

Seaman Apprentice
Joined
Mar 6, 2016
Messages
33
I am having some issues with my kicker losing fuel pressure and I think it's something to do with the fuel line so I want to replace it and the primer bulb. What thickness of line should I get? 1/4", 5/16" or 3/8" (which I believe is used now)? The line will be about 8' long.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
depends on how you rig it and where and how you tie it into the fuel system.
a 9.9 does not take much fuel to run so does not need a big line

do you have any check valves or manual valves to keep from sucking air from the other motor's fuel system?
 

DollarBoat

Seaman Apprentice
Joined
Mar 6, 2016
Messages
33
It is tied into my main tank through the fuel separator. There is a manual shut off valve at the separator.
 

99yam40

Fleet Admiral
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Sep 7, 2008
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8,851
so does the main motor run OK, just the kicker is loosing fuel pressure with the valve opened?
is there a valve to shut off the line to main motor also?
 

DollarBoat

Seaman Apprentice
Joined
Mar 6, 2016
Messages
33
Main motor seems to be running fine. I have noticed on the main if I am WOT, the motor will start to hesitate, bogging down a bit. This might be a totally separate issue though and I never go WOT so I have left it. I have recently replaced the anti-siphon valve on the tank trying to fix the main motor hesitation, which it didn't. And no, there is no valve to shut the line on the main motor.
 

99yam40

Fleet Admiral
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Sep 7, 2008
Messages
8,851
so is it possible that the kicker is sucking air in from the main motors fuel system when you open the valve and run the kicker?

as i said before a 9.9 does not take much fuel to run so does not need a big line
 

tommarvin

Ensign
Joined
Nov 22, 2015
Messages
999
1. You only want to use USCG A1-15 fuel line, it has a 2 1/2 min burn time, have to fire extinguisher very close.
2.We have 5/16 ID for a 125 hp force, works fine,
Stop all air leaks, we use stainless steel hose clamps on all hose connections.
 
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