I have opened it a time or two Mattsz... since tearing engine down for high compression piston, ported head, new valve train...then going back in to install Hitchcocks cams which unbeknownst to me were defective,
(early prototypes, H now selling good ones) had them in and out 3 times, put stock cams back in, replaced those with a set GHG custom made for me, having ring seating issues for which I removed piston again, (may have had upside down compression ring), and multiple re-adjustments of the adjustable pushrods... Putting bike back together and riding between each occurance...other than that, probably not any more than the typical person.
Why do you ask?