Is my fuel line the problem here?

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ptbrakefield

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I have a 1974 Starflite 135. The boat has a built-in tank, but I also carry a spare 6 gallons "just in case." Well, last Sunday, "just in case" happened, and I needed to switch to it. My built in has a 3/8" hose. I have a 5/16 hose for my spare. The motor would NOT run on the spare tank... it would run a little, or if I hit the choke. Luckily I was close enough to the dock to get back a little at a time, but I do NOT want to go through that again.

Would the 5/16 hose be the culprit here? The motor went from purring like a kitten to barely running, and the hose switch was the ONLY thing different. The spare tank is a brand new Atwood plastic tank with the proper fittings...

Thoughts?
 
Scott Danforth

Scott Danforth

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most likely the fuel line is breaking down internally and the low quality attwood fittings are not helping either.
 
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ptbrakefield

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The fuel line is brand new... I also have an old Cruise a Day tank... might try the hose on it and see what happens.
 
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F_R

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IF the 5/16" hose is the culprit as you suspect, the problem would be at wide open throttle when it is really gulping fuel big time. Since that does not appear to be the problem here, I would not suspect the hose. More likely it is sucking air at a leak somewhere along the line. The connector at the tank is famous for leaking.

Or, how long have you been toting that just-in-case gas around? That stuff doesn't last forever.
 
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ptbrakefield

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F_R said:
IF the 5/16" hose is the culprit as you suspect, the problem would be at wide open throttle when it is really gulping fuel big time. Since that does not appear to be the problem here, I would not suspect the hose. More likely it is sucking air at a leak somewhere along the line. The connector at the tank is famous for leaking.

Or, how long have you been toting that just-in-case gas around? That stuff doesn't last forever.
Click to expand...

I was/am worried about the hose because I thought I read somewhere, in passing, not really looking or paying attention, that you can go from 3/8 to 5/16 on small engines, but never on larger engines. However, your point makes total sense. I was never close to WOT... it wouldn't even idle.

The fuel is just a few weeks old... now the connector I will check. I have teflon on the threads, but I will be sure it is all tight. Thanks for the response.
 
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F_R

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I was there when they came out with 3/8" hose, but don't remember the specifics. But to the best of my memory it was because the 200hp V-6 motors were starving for gas.
 
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ptbrakefield

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racerone said:
Do some testing / inspection on this motor.----Size of the hose is not the issue.
Click to expand...

Ran perfectly all day... built in tank ran out as I was coming in to the dock. I wasn't close enough to dock, just headed that way. The wind pushed me well down from the dock. I switched to the spare tank, hit the starter, and it wouldn't run... it would if I hit the choke. I kept it going just enough to limp it back up the lake to the dock. I will do some looking, but I have no clue what could have gone wrong during the 30 seconds it took to switch tanks.

I'm going to fill the main tank and switch back to it Sunday when we go back to the lake. If it runs I'll know it's the spare tank. If not, I'll know it's the motor.
 
interalian

interalian

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I'm going to assume when you switched tanks you re-primed it. Otherwise you would have been low on fuel.
 
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ptbrakefield

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I've actually just thought of something else... I got it to running and idling... but whenever I put it in gear it would die. When I finally tied up I disconnected the fuel line to run the fuel out of it and it idled until it ran out of gas. I might find that it runs fine when I put it in the water Sunday.

The bottom line seems to be, thought, that the 5/16" fuel probably is NOT the culprit... correct?
 
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F_R

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Correct.
Another thing that has not been speculated: Could have water in the gas. Sometimes condensation, often times it comes right out of the gas station pump.
 
Scott Danforth

Scott Danforth

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or the low quality chinesium Attwood fittings have an issue.
 
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Bluedogfishing

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Fuel line is backwards. Disconnect from motor and tank and switch around. Check direction arrow on primer bulb to make sure it is heading to the motor.

Ron
 
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G dog

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I had a friend that had a similar problem with his pontoon boat. He repowered his boat and bought a new hose and ball. It would not rev. up and would die. It turned out that there was a plastic BB lodged inside the hose.The same grey color as the new hose. It came that way brand new out of the package. We replaced the hose with regular fuel line and it ran like a champ
 
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