humidity and high octane fuel

I'm just throwing this out there. My 86 vfr750 was running fine until I put in 93 octane gas and the outside humidity went to 100%. It feels like it has about 1/2 power but I haven't investigated anything yet. You hear the stories about 93 octane gas sitting around and going bad, and I've also heard that drier air requires higher octane. I've never heard about negative effects from too high of an octane rating though. Usually I get the 89 octane stuff and it's been fine.
The bike's ran so well I bet If I drain the tank and try some different gas it will run fine. Any similar experiences?

One last thing: I have a K&N 'high flow' air filter I want to try. Anyone experience problems with this? I have the stock exhaust, stock airbox and stock carb setup and I don't want to mess around with rejetting.

 

A K&N air filter should not require a rejet unless you are pretty lean. I would recommend richening up the pilot jets a touch though. Stock settings are pretty lean to begin with.

Typically, if you change the air filter and exhaust SYSTEM, you will need to rejet.

It's been discussed before - use the lowest octane rating your bike will run without knocking. Anything higher and you're just putting carbon on your combustion chamber and wasting money.

 

interesting thread.

I have an 02, and have recently been experiencing what appears to be a loss of power between 4-5k rpm. I have seen others post similar things and there is discussion of some vacume hoses coming undone. I live in tx, and its been hot and humid, and for no good reason i generally burn high octane fuel.

Can this perhaps be causing my issues? I have always done this, but this is the first summer with my bike.

Any advice is appreciated.