Help with a shovelhead fuel delivery problem.
#1
Help with a shovelhead fuel delivery problem.
I need some help from the shovelhead gods here.
Little about the bike:
1977 FXE
S&S shorty super carb
Intermediate jet: 27
Main jet: 70
Stock engine 74ci
The tank is clean, the inner tank filter is clean, the in-line filter is clean. There is no trash or obstructions from the tank to the carb.
The problem:
The bike will run fine till it gets to half tank. Then the fuel filter will run dry and the bike will cut out then die. If I blow in the tank, it will refill the filter, and run until the filter drains empty again. It will continue to do that until I fill the tank back full again. Then it runs fine until there is only a half a tank in it again. I've pulled the tank and filter twice, and there's nothing in it. The venting valve in the gas cap is working like it should. The tank is building pressure through out the run. I'm stumped. I'm open to all suggestions please.
Thanks in advance from my son and I.
Ricky
Little about the bike:
1977 FXE
S&S shorty super carb
Intermediate jet: 27
Main jet: 70
Stock engine 74ci
The tank is clean, the inner tank filter is clean, the in-line filter is clean. There is no trash or obstructions from the tank to the carb.
The problem:
The bike will run fine till it gets to half tank. Then the fuel filter will run dry and the bike will cut out then die. If I blow in the tank, it will refill the filter, and run until the filter drains empty again. It will continue to do that until I fill the tank back full again. Then it runs fine until there is only a half a tank in it again. I've pulled the tank and filter twice, and there's nothing in it. The venting valve in the gas cap is working like it should. The tank is building pressure through out the run. I'm stumped. I'm open to all suggestions please.
Thanks in advance from my son and I.
Ricky
#2
Join Date: Jan 2011
Location: Southeast Michigan 15 Minutes East Of Hell
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The tank is building pressure through out the run .... Pressure? When you release/open the gas cap you hear pressure or are you hearing vacuum? ( the tank sucking ) I'd say you have a vent problem. Do you have "dual tanks"? A single gas cap would lead me to believe that your cap ( contrary to your assertion isn't venting.
#3
#4
Join Date: Jan 2011
Location: Southeast Michigan 15 Minutes East Of Hell
Posts: 147,588
Received 47,744 Likes
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18,543 Posts
Yep that's a possibility also
#5
The tank building pressure through out the run .... Pressure? When you release/open the gas cap you hear pressure or are you hearing vacuum? ( the tank sucking ) I'd say you have a vent problem. Do you have "dual tanks"? A single gas cap would lead me to believe that your cap ( contrary to your assertion isn't venting.
Yes, the fuel line IS routed through the cylinders, and no, there's no additional protection on the lines. Could that be all there is to it? What do I need to fix it? And where can I find it?
#7
Vented gas cap,(right side) not working correctly.
Scott
Scott
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HILLSIDE MOTORCYCLE & MACHINE, INC.
HARLEY-DAVIDSON SPEED & SERVICE CENTER
5225 SOUTH MAIN ST., MUNNSVILLE, N.Y. 13409
Sales/Support 315-495-6650
www.hillsidecycle.com
Walk-in Retail Showroom
Complete H-D Machine Shop
Case & cylinder boring
Complete Cylinder Head Shop
High-Performance Engine Kits
Crank Rebuilding
Direct Link & PowerVision Tuning
Goodson HD Tooling Manufacturer
Maxton Mile World Record
4500 sq ft. facility
OVER 35 YEARS OF H-D ENGINE BUILDING.
See us on Facebook.
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