If the bike is new to you it would probably be worth taking the fairings off and giving a once over. Clean the carbs, check air filter, check rc valve adjustment, while you are at it and seen as you are riding with mates on 400 i would carry out the wire splice then you have full power all the way up (easiest job of all) and just have a look over all the bike and check all fastners are tight and everything is ticketyboo. All the info on wire splice and rc valve setting is in the tuning section as mentioned by Dana.

Hope that sorts it.