Originally Posted by Lothos
Bike was running great on Tuesday. Rode 20 miles just fine then poof ran out of gas. Put some gas in and it would turn over but not fire. Tried to jump it through the clips off the battery tender but it wouldn't get any spark and the battery got hot. Got a new battery, started right up. Every time I run it now though I get a mile or so and it acts like it's out of gas. Turns over, won't fire. Been sitting a bit while waiting for some parts. I figure it's the carb and was going to rebuild it (S&S E). The battery acting up made me possibly think there's some weird short too but can't see how that's related to how it's acting now.
At the risk of getting attacked, I will say that in my opinion, the S&S type carburetors are not the easiest starting carburetor on a Shovelhead. I expect to be attacked and drummed out of the internet community for that, but I won't retract that statement.
It's possible that your fuel tank is clogged with old Kreem flakes or rust particles. I would remove the petcock and see if it isn't clogged. That's not uncommon for older bikes.
A CV carburetor would be a good choice to replace your S&S. The problem with both the original side-draft Keihin and the S&S is that they let too much air in when starting the engine. The CV is much tighter what with its diaphragm and the slide closing at start up.
It almost sounds like you have two different problems. First, if you have a weak battery.....well, you have a weak battery, You must understand that a Battery Tender will only put out at the most about an amp and a quarter. They are not a battery charger or a battery jump start device. They are for like overnight or longer recharges and maintenance.
As to the possibility of a parasitic short, you can check that with an accurate ammeter, one that can read down to a milliamp range. Just park the bike, remove either battery cable (positive is ieasier to reach on a Shovelhead) and see if there is a current drain. Even one of 50-100 milliamps (1-20th to 1/10th of an amp) will drain a battery down over a day.
If you have a short such at this, then it's time to start looking at both ends of each wire in the loom with a good voltmeter. There should be no grouinding pathe from any wire to the frame. You can check continuioty from end-to-end on a wire and from one end of the wire to the frame. I once had to do every last wire in my Shovlehead to find a short in one of the connectors inside of the headlight. I finally re-wired the whole bike to simplify the wiring but it drove me nuts finding it the short.
The S&S is a nice carburetor for drag racing. For starting and cruising, there are better choices. Anything with a slide would be my choice. CV or Mikuni would be OK.
S&S carbs sell nicely on eBay, too.