A while back, someone posted about this using some home made concoction that included "mint oil" or something like that. I tried to search for it last night and came up empty. Who posted this?
I saw that thread, and the results are terrific!
I got 16 ounces of Wintergreen Oil from Amazon.com, mixed it 50/50 with a can of Xylol from Ace Hardware, soaked the first set for a night, and...nothing. Then I left on a business trip and forgot about them. Seven days later, they are brand new!
So, I took out the second set I have. And the third. And the fourth (16 all together). They are all brand new, except the ones soaking tonite, which were like rocks. I even soaked the air horn (inlet side) velocity stack boots: they should not be soaked more than about 24 hours, max, or they get too big. They are polyethylene, and expand a bit. I may try baking them back down: I soaked them for a week, too. They also feel brand new, though!
My next attempt will be to see if this can help the unobtanium versions, like the Kawi 650 inlet velocity stacks. They are as hard as plastic. I am completely convinced that this works so well that I am going to do it to every Four that shows up in my garage for a week or more, as part of the tuneup.
And I'm going out to buy stock in some wintergreen oil company.
It smells like me in the garage, though: that Ben-Gay scent...