Fuel System Cleaner that works as advertised, Great stuff!

[Grimly]

I've had really good luck with Techron complete fuel system cleaner. That is what I recommend to all of my customers for use once or twice a year. Especially if they let the bikes sit over the winter months. Stabil works well for winter storage but I have them add the Techron when they "wake the bike up" in the spring.

Ditto. I found Techron when I filled my tank with Texaco (the Texaco station is nowhere near my normal route). Within a couple of miles I was starting to feel a difference and by the time I got back home, the engine was running a noticeable amount smoother than it had done for a while.
I knew the normal maintenance was ok, so that just left the fuel as the only thing different.
The next couple of tankfuls of the normal petrol I buy had the engine being back to the way it had been before, and since the Texaco station was so far away, I found out what the addditive was - Techron.
I started buying Techron a couple of bottles at a time when I was in town, and whenever I filled up with run-of-the-mill petrol would add the required amount of the stuff. I've been convinced of its virtues ever since.
Most of these things claim a lot, and I'm a bit sceptical of most of them, but Techron actually does what it claims.