I use these mini mushrooms and have one in the rear tyre of the Fazer 1000.
http://www.morrisonbhp.net/apps/webstore/products/show/3681925 It survived a very very hi speed trip back from the UGP with Mark.
First time the fuel light came on after only 120 miles
.
I have two packs of them one under the seat of the 600 and one under the seat of the 1000 all the time. Had to use 2 in total.
Put a bit of spit on them before using as it helps them to go in easier