Which bolt are you referring to? The little "screw" under the meshfilter, sort of "under" the engine? Those are a b*tch to get tight and dry. I ended up using both a crushwasher and loctite.
The meshfilter is pretty tight, so make sure you use a perfectly fitting tool if your removing it.
2010 Multistrada 1200S Sport (White)
Mapped by Hypertrick in stock ECU
Íhlins semiactive SCU