[lowspeedpursuit]

Yesterday my 250 newgen would barely accelerate, especially from a dead stop. Ran worse and worse until it would die with enough throttle. Idled completely fine. Plugs look fine. Ran slightly better on full choke, so a fuel problem. This is the 2nd time this has happened; last time I was home, drained and filled the tank and things went back to normal. This time, I left the bike running, and after idling fine for 10-15 minutes I was able to accelerate like normal and drive home. The bike was already hot, so I feel like this implies a small clog or bad gas which eventually cleared? I have a real inline fuel filter, and I've checked the vacuum line and petcock with my vacuum pump, so that points towards bad gas.

I need to figure out why this is happening so I don't end up stranded away from home. There was an extremely bad storm this past week; could rain be infiltrating my tank? The big seal on the gas cap looks decent, but gas leaks out easily if you turn the tank upside down without draining it. The vent and drain holes near the tank filler are free of any major blockages. I don't see any water in the gas I drained, but I could see there not being very much and managing to stumble through it when I left the bike running.

Thoughts?

EDIT: This topic took a couple days to get approved, so I had some more time to work on it and the seal is definitely toast, it has a slit between the top and bottom sections, on the left side in the 2nd pic where the rubber has that bubble. What are people doing to replace these? Officially the cap is a complete assembly for $130+ and then you'll still have to switch over the locks, which is pretty ridiculous, and I'm not really interested in buying used to replace a seal.

EDIT 2: So I never got any feedback on this, but for the sake of anyone who finds this later with a similar problem, I grabbed one of those screw-on billet aftermarket gas caps you can find on amazon or ebay for $30 - $50. Still expensive for a seal, but it was always frustrating how my keys would stick in the locking gas cap anyway, so win-win. It's rained since then and my bike hasn't freaked out, so here's hoping I was right.