Fuel line

[eedwards]

My 79 90 hp has 1/4 inch line on it now is that the correct size?
That is from tank all the way to the carbs.

 

[eedwards]

Re: Fuel line

Someone has to know what size to use on a three cylinder.

 

[Reboot11133]

Re: Fuel line

My 1984 85hp has 1/4 inch fuel line. I suspect the 90 is the same.

 

[Frank Acampora]

Re: Fuel line

Well, the fittings that the line connects to are less than 1/4 inch in inside diameter and the inlet seats on the carbs only have about a 1/16 hole in them. So, theoretically and probably practically 1/4 would be ok. EXCEPT: If you have a long run of fuel line from the tank to the fuel pump, internal resistance will slow fuel delivery. If it is working well now, leave it alone. If you need to replace the line, it would be better to go to 5/16 or 3/8 line. 3/8 ID hose will fit the black plastic inlet screen, but will be loose on the carb fittings and fuel pump outlet fitting. It is better to use 5/16 ID hose there.

 

[eedwards]

Re: Fuel line

Well, the fittings that the line connects to are less than 1/4 inch in inside diameter and the inlet seats on the carbs only have about a 1/16 hole in them. So, theoretically and probably practically 1/4 would be ok. EXCEPT: If you have a long run of fuel line from the tank to the fuel pump, internal resistance will slow fuel delivery. If it is working well now, leave it alone. If you need to replace the line, it would be better to go to 5/16 or 3/8 line. 3/8 ID hose will fit the black plastic inlet screen, but will be loose on the carb fittings and fuel pump outlet fitting. It is better to use 5/16 ID hose there.

What do you consider a long run?
I probably have six feet of line now.

 

[Frank Acampora]

Re: Fuel line

Six feet is about average. Most replacement hoses and bulbs are about that length.

My Glastron with a 90 has the tanks under the seats so the hose is about 10 feet. I'm using 3/8 there.

Mt 125 on a 14 footer turns about 5800 at 55 MPH with about 7 feet of hose. It uses 15 gallons in 1 1/2 hours. I use 3/8 hose there also.

Personally, I prefer 3/8 hose, however, my 6 foot emergency hose (to connect a reserve 3 gallon tank to the engine) for my 140 is 1/4 inch and seems to supply it during tests. So the decision and choice is yours.

As I said above : If it is supplying the engine without starving now, use it. Why spend money to get a larger size if the current one is doing the job?Change it to a larger size if the line and fuel primer bulb get hard or cracked.

 

[eedwards]

Re: Fuel line

I replaced it today with 3/8 since thats all anybody had and the bulb was bad.
I hope this solves the mystery problem of bogging at WOT.