@Warrior - thanks for that, I'm still not sure - I can see your point about the pit time having to be taken at some point while I still see that stopping on the first lap gives me 2 flying laps as opposed to one, I think it was Bob Jackson who had a big 3 lap tank on his bike way back in the TT Senior and it seemed to move him further up the positions compared to where his 2 pit race speed would have normally put him, I ran a 7 gallon tank(1 and 3 laps) on my TZ way back in 92 and I beat a few mates who normally I'd be finishing behind, back in those hazy days the TT F1 race had a limit but I don't think the Senior TT had a 24 litre limit neither did the MGP. 7 gallons on the TZ did make the bike noticeably "quicker" into Quarterbridge after pitting as I recall - whooooa hoss haha.

Does anybody know how much over the 24 litre the tanks in question were ?.