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Steve, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 6993
Experience:  30+ yrs. experience, MMI, HD technician, HD early, engine rebuild/performance, bike builder, kit bike program manager, CCI 2001-2004
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1974 ironhead sportster as a project bike..rebuild..carb

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I have a 1974 Ironhead Sportster as a project bike, I know nothing about it, never worked on one, but I figure if I mess it up no one will care. The fuel line is hooked up through part 48 as listed in the rebuild diagrams called returns line elbow part number 27847-71 on the left side of carb when facing it. When I turn the fuel line on it it literally flows out of part number #27841-71 inlet valve needle. The bike will run and rev but won't idle, I need to keep the trottle up for it to stay on. I got schematics for the carb, But can't find any diagrams on how to set the fuel lines so I don't even know if its hooked up right. Any ideas how correct this? I want to get the bike running minimally before I break it down so I know its worth it.

Welcome. Thank you for choosing Just Answer.


what "rebuild diagrams" are you looking at?



Customer: replied 5 years ago.
I found it here

the expanded view is on page 8 and the parst list follows on 9 & 10

that PDF is parts pages for SNOWMOBILES and has nothing to do with a 1974 Harley Ironhead 1000.

this is NOT your carb.

here is a link to a blow up of your carb


your bike has 1 fuel line and NO return line.

the fuel line attach's to the fuel petcock on the fuel tank. the other end attach's to the fuel inlet on the carb.

the stock carb for your bike is on the lower left side of the page on this link

the fuel inlet is on the left side.


your carb has a float bowl over flow outlet to prevent flooding the engine with raw fuel should the float/float needle fail to shut off the fuel.


you should remove the float bowl and clean/inspect the fuel inlet seat, float needle and float.

the rubber tip on the needle should be soft and rubbery. if it has hardened, the needle will need to be replaced.

if the float has cracked or developed a hole and has fuel inside it, it will need to be replaced.

ensure the fuel inlet seat is clean and there is not debris in the float bowl to prevent the needle from seating in the inlet.


let me know if you need more help.


Customer: replied 5 years ago.
Well I feel like an a$$, someone sent me the link and I didn't even read the first page...anyway. I am sending a pic just to be sure. There is a brass nipple inside the chamber that is visible in the pic and one underneath that is facing away that looks the same to me but you can only see the nut portion in the pic that is square with a nipple facing the engine at 90degrees (#10 I think on the info you sent, but there is a nipple facing the engine that looks like the visible one inside the chamber). When the fuel is turned on the fuel flows out of both in a continuos stream. The fuel is connected on the left side and is visible. It is my intention to restore the bike using as many original parts as possible so I would like to rebuild this one if you think it looks original. If so can you tell me what rebuild kit I need (i.e. part number)? If this works out I will get the unlimited question program since I know I will have more and would like to work with one person if possible throughout the rebuild. I'm good with my hands but lack the experience.graphic

I am having some trouble following your description, however, the brass tube sticking up in the throat of the carb is the main jet holder.

if fuel is squirting up through there, you have a float/fuel inlet problem.

read my answer above and find and correct the issue.


remove the fuel filter. throw it in the trash.

if you have junk in the fuel tank....clean the fuel tank.


purchase a HD factory service manual.

the one I have has no part number, so I'll do a little digging and see if I can find you one.



sorry for the delay.

check out this link

I highly recommend the purchase of BOTH, the Service manual AND the parts catalog.


by original factory HD manuals only.

Clymer and Haynes are not recommended. they contain mis-information.


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