78 GS550 running like a bitch

I have my bike on the road. Ive had it going for about a month. And it had been running not to badly. At idle the rpms do vary a bit more then I think the should. Sort of vary up and down by about 50 to 100 rpms or so.. But I wasnt to concerned. One day about 2 weeks ago at a stop light the rpms just dropped right off and the bike died. Started back up but had to keep revving the engine at stop lights to keep the bike from dying. I got home and turned the idle up a touch. To maybe 1100.. (Was at about 900ish). It seemed ok.The other day we got a massive dumping of rain while the bike was parked outside at work. I came out after work to head home. The rain had stopped a good 40 mins before. Started her up and made my way home. But as I rode the bike seemed to keep losing power. Cruising along then power would drop of then come back up. At a stop light. The bike just died out. And this time I couldn't get it to start back up.. Almost felt like it was out of fuel. But tank was still full. I managed get it back up and running after quite a bit of effort. I dashed it the rest of the way home. Trying not to stop.I am wondering if these issue sound like an ignition issue? Timing perhaps? Maybe the spark plug wires have shit the bed? As I have not replaced them.. Anyone have any thoughts? via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/8wv118/78_gs550_running_like_a_bitch/?utm_source=ifttt