Join Date: Jun 2009
Location: Otero County, NM
If I did not understand the operation of the typical petcock, the replies to your post might confuse me further - which is another way of saying I'm old and sometimes have trouble understanding things. So . . . in case you do not know . . . refer to the attached JPEG of the petcock fuel strainer (as HD calls them) or filter, which I have cut away for illustrative purposes.
The concept of the "reserve" tank is often misunderstood. In fact, there is no reserve tank. What there is is one or two feed tubes of different lengths extending upward within the strainer from the petcock (which HD calls a fuel valve, by the way). The HD strainer uses one tube - the large central tube you see in the cutaway view. Although you cannot see it in the image, this tube ends at the wide horizontal band 2/3rds of the way up the strainer.
When the petcock valve is turned to the "On" position, fuel is fed to the engine (carb or AFI) through this tube. When the petcock valve is turned to the "Reserve" position, fuel is fed to the engine from the bottom of the strainer or a second very short tube near the bottom of the strainer. (Some applications use a second short tube to keep the fuel flowing from the very bottom of the tank where one can imagine most of the sediment would settle.)
So, I ask, why would you have to run on "reserve" all of the time? To say that the strainer might be clogged would not be the first possibility on my list because the "on" position feeds fuel from well above the sediment level. If anything, I would think that the "reserve" position would cause sediment issues.
One possibility could be that the primary feed tube (petcock in the "on" position) is blocked. Now, you might say, "They replaced the petcock assembly" - and it took them more than two weeks! Really? HD's vacuum operated petcock has two hoses (fuel and vacuum) and a nut that attaches it to the fuel tank. You are talking a two-hour job here that includes draining the tank, removing the fuel and vacuum lines, removing the petcock, flushing the tank, and reassembly. More than two weeks? They busy? Even if the shop did not have one in stock, two weeks to get one? Really? So my first question is, did they replace the petcock assembly?
Could the screen be clogged? How, they just replaced the petcock assembly? Unless one does not mind spilling fuel all over the place, to replace the petcock, one has to drain the tank. Once the tank is drained and the petcock removed, any conscientious crew would flush out the tank to remove sediment.
So, what to do? First of all it does sound like a petcock/strainer/sediment issue but how, what? Who knows? What would I do: remove the existing petcock, clean or replace the strainer, make sure the "on" position feed tube is not clogged, flush the tank, reassemble. Or, my first choice would be to replace the petcock. For $20 you can obtain a petcock that includes the on, off, reserve positions, that includes the strainer, and does away with the vacuum break (a source of difficulties). At the same time, you flush the tank.
My bottom line is, I don't know what, if anything the dealer did so I'd do it myself.