Not sure how to even describe this because the issue is intermittent.
Just got it a week ago and I've resolved a few other things but the new issue is a stumper. The bike is seeming to stall after running for 10 or 15 minutes.
The time to stall was quicker this morning, when I set off. But after I took the carb off and cleaned it it seemed to be humming along. Where it was previously stalling at every red light (but would kick right back up when it was time to go again) now it was idling at red lights fine. Seemed to have more power, too.
But sure enough, as soon as I got about 5 or 6 miles up the road it stalled again. And the stalling I'm having trouble with is different that when it was cutting out at the red lights. The red light thing was only while idling, this is more like it's running out of gas. I'll be cruising along at a decent speed and it just kills. It almost seems like it happens most when I'm throttling it up but I'm pretty sure it's also happening when just cruising at a steady speed. Once it starts doing this, I can move the throttle around to find a sweet spot where it wants to run. And I'll eventually lose it. But I can muster another quarter mile or so of starts and finding the sweet spot but then it stalls more and more frequently and then it just won't start anymore.
When this happened earlier today, I took it up some hills and pretty much dragged it down with the clutch on. It would spark, and even respond to the throttle a bit, but it felt weak. And as soon as I let go of the clutch it would die.
I swapped the spark plug so I know that isn't it. The only sense I can make of it is that it's happening after heating up.
Oh, after I peddled home this morning, after 30+ minutes of trying to get it started again, I let it sit for a few hours. Then it started right up. Ran for 5 minutes then started that stalling again. It's always mild at first. Allowing some starts, but after a few minutes I lose it.
After that rest, and then stalling again, I cleaned the carb, it ran like a champ (with strong idle even) before the stalling finally took me down again about 10 or 15 minutes into the ride.
Sorry for the lengthy steam-of-conscience prose. I'm too tired to clear this mess up right now. (edited)