Sea Foam cured my GL 1100 from eventually running on 2 - 3 cylinders. My Vmax 1200 was cured with Sea Foam as well. It was misbehaving. I didn't do the 'shotgun' (I thin that's what you perhaps did), but disconnected the pump, connected a small funnel, filled it with Sea Foam, and let the engine suck it in until it dies. I let it sit overnight, drained the bowl, and repeat one more time. Done! Smooth as a whistle. That's 4 years ago. I've been using Sea Foam periodically as a preventive measure, and I am still running the same carbs, never removed for cleaning - because they don't need to! I used Sea Foam on KZ1300 a couple times. Not sure what it did, but my carbs are clean so it was just a thing to do. If there was something in there, definitely adding it didn't hurt!
Recently adding Mystery Marvel 0il, I soon felt improvement in all three bikes. They run much smoother. Also, like I said earlier, Sea Foam didn't clean any carbon in the cylinders, and they had the expected after use carbon build up on top of the pistons. After the 0il treatment - they look clean as installed yesterday. Same spark plugs - no carbon on them.
So, my system from now is adding the expensive Sea Foam once in a while, but using the Marvel Mystery 0il on a more regular basis. It's much cheaper and does a great job. Definitely, in terms of lubrication as well, cleaning, and not just cleaning carbon deposits. Who knows, based on experience Sea Foam did good deep carburetor cleaning, so I will be using it with that in mind.
