Welcome mate and DONT WORRY about asking questions, thats what the forum is here for!! You have been given excellent advice from Pleiades so I would suggest getting used to your bike as it is and then think about the mods you mentioned, the Kev fuel mod is fantastic and really changes your bike. The Stage 2 filter is also excellent, so I would take my time and plan your moves, an after market exhaust also removes weight and lets your bike breathe better. Have fun!!!

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(Now sold on, sob) 2011 Blue XT660X with gold wheels, was 26,500 km.
Engine mods: K&N Stage 1 filter, DNA Stage 2 filter, snorkel removed, Kev fuel mod fitted.
Plus: smoked Puig screen, Yam aluminium sump guard, Yamaha / Acerbis handguards, Givi Trekker aluminium side cases, Leo Vince X3 cans plus Kev front fork mod and Fender Xtender. Just fitted Michelin Road Pilot 3 tyres.

SOLD the XTX for a Super Ten 1200. And just bought a Raptor 700 so staying on here for some tips....