Sure sounds like it's fuel starvation of one sort or another. It sucks that you paid good money for a 'tune-up' (when it was already running fine before) just to have them screw something up. That said, I suppose it could be a coincidence in timing, either with some dirty gas or something dislodged in the tank from a 'cleaner' that also probably wasn't required. If bikes (even 20 year old ones) are put away properly, they don't need all this attention. It is make work for the shops. Before you do anything else, I would carefully lift the tank, a 1/4 inch at a time with thicker and thicker blocks (or have someone hold it) and use a power light to look under the edges. Try to confirm the routing of the hoses before you do this so u know where to look. I recommend doing this at night, with as little background light as possible so the flashlight you are using will be the only light around. It's easier this way to spot a pinched, or kinked line. The fact that it runs on PRI sorta helps confirm the need to at least rule out this 'free' check by yourself. And as someone has suggested, confirm there is no cracked lines as that is possible on a 20 yr old bike.
Your meter is probably not a load tester per se. (altho - see below). It looks like an analogue volt/amp meter. They actually are easier to read while watching during a load test (while starting the engine right?) than an electronic multimeter as they read out faster. Same for when you are checking amp draw, except that few old analogue meters check greater than 400 mlA so not that useful around a bike for lighting or heavier circuits.
So ya, your meter can help load test the battery while starting which will tell you something as to the condition of the battery or the charging circuit to restore it after a start, but it will not induce a load on the battery on its own, which is what many mean when they talk about load testing a battery. That type of tester is not cheap, and is why most will remove a battery and take it into a shop for a free test. BUT! beware of those tests also if they don't know what they are doing as they can kill a battery that normally wouldn't have failed for 2 or more years yet.
My sealed battery is original, but is cared for. (kept charged over the winter, with an electronic 2 amp charger, (but not left on even tho it is an auto). I also keep the battery clean between the terminals. I do not run extra high draw lighting (just a few lo draw LED's) I recommend you undo the neg wire over the winter. Or if not, and u have an alarm and the alarm to work, then you need an auto charger (like a CTEK) full time. Alarms on monitor pull a lot of juice and could kill your 2.5 year battery with a few other things working against you like mentioned above.
Keep the top clean though, this helps a lot. And if it is not sealed battery, then others here can fill you in on caring for those...I have to run here right now...but never over fill, just always keep the plates covered plus a small amount more, and always use known distilled water..very important. I know u bought a new battery, but just so u know for it..
