Hey guys,
My 91 FLHS has an occasional problem of leaking gas from, what I think, is the carb overflow tube. I see it in a puddle under the bike. From what I can tell its not leaking from anything and trickling down the motor, its just coming out of the small tube coming from the carb. If I turn the petcock off it won't leak. I popped off the carb cover and filter today to see if I could see what was going on.

The first thing that I noticed was that I am woefully undereducated in motorcycle carb knowledge (like how to even remove it), the second thing I noticed was this elbow:

closer look:


that I think brings gas from the tank to the carb, is cracked and leaking.

If I wipe the elbow I can watch gas slowly leak out and saturate the elbow. However it doesnt drip off the elbow even if I leave it for several minutes (However I just realized that when I tested this the petcock was off. So there may not have been much gas in the tube). I'm wondering if this may be the culprit of my occasional gas leak?

If that would not be the reason for the gas leak I would absolutely love it if there was a member close enough to me (Simi Valley, southern California) that could come show me a thing or two about removing and inspecting the carb or at least someone who could give me a step by step guide to removing the carb and checking it out. I would gladly buy lunch and beer.

 

It very well could be.

First thing you do is replace that elbow.
The upgraded part is brass and a hell of a lot harder to crack than that plastic one.
The second thing you do is get some polishing compound and some q-tips and clean your needle seat.

Assuming your float is set correctly doing those 2 things will stop your fuel leaks.

 

"Fitting" #47. Part number 27371-76.

Here's a write-up I found in another forum for how to remove the cracked one and install the new one. I've never done it myself, can't vouch for how correct this write-up is. (I don't know what steps 1 and 2 are, but one of them appears to be "remove carb from the bike".)

New brass inlet is HD part # 27371-76

3. Note the position of the elbow and mark it on the carburetor body. This will allow proper positioning of the new elbow.
4. Break off the plastic portion of the original fuel inlet elbow. This will leave the brass portion projecting from the side of the carburetor.
5. Using a ¼-20 or ¼-28 tap, tap the remaining brass piece approximately ½” deep.
6. Remove the tap and insert a ¼" x 3-4" long piece of all thread into the now threaded hole. Do not go so deep as to damage the carburetor body.
7. Use a piece of tubing that is large enough to go around the outside of the opening to act as a spacer. Place a washer on top of the spacer and over the bolt. Thread a nut down onto the washer and gently tighten, pulling the
brass piece out.

IMPORTANT! DO NOT SKIP THE NEXT STEP!

8. After removing the brass piece, wash the carburetor body with hot soapy water. Remove any debris or chips.
9. Mount the body in a vice with the inlet hole facing up.
10. Heat the carburetor inlet area. This will ease installation of the new elbow.
11. Position the elbow lining the elbow portion up with the mark you made previously.
12. Quickly insert the elbow into the carburetor body. You may need to gently tap it in to seat it. Do not distort the body!
13. After positioning and installing the new elbow, thoroughly clean the carburetor body.
14. Reassemble the carburetor following your service manual. Install new seals and gaskets as necessary. Check for proper float height.
15. Reinstall the carburetor and check for leaks before doing a test ride.

FWIW, another guy in that same forum just grabbed the protruding brass part of the old one with a pair of vice grips and twisted it out, instead of using the procedure above.

 

That's the procedure I used when I did mine. The only thing I added to it was to stuff some wheel bearing grease in the nipple before cutting the threads. The grease will catch the cuttings.

 

There's more than one replacement brass inlet. The one I bought wasn't flat and it was a real pain to press back in. Try to find a flat one it will make your life easier.

 

what do you mean by "flat"?

 

Never mind. I guess it's not your overflow that leaking.

 

Yanking the carb is the part I'm not familiar with. How does it come off? I poked around and couldn't really tell how it was secured to the intake. also, If I am going to take the carb apart, is there anything I should replace, aside from the float? gaskets or anything?

I already checked the cap is venting and the hose isn't obstructed. I went for a ride today and left the petcock open after and it leaked gas right away, and plenty of it. Closed the petcock and instantly stopped. So it's gotta be the float bowl or that elbow.

 

That is because your needle seat is dirty.
Do what I said in post #2 and it will solve your problems.

 

If the needle seat is that dirty, I think I would probably take it completely apart, clean everything thoroughly and put it back together. That would be overkill, but I had too many carburetor headaches with my Sportster in the 90's to not want to bite the bullet and get every last piece of debris and sticky stuff out of there.

Oddly, my Heritage's carburetor has not been problematic like my 91 Sportster's was (until I nearly poisoned myself cleaning it lol)