Hi All A Couple Of Questions

hi all looks like i am in the right place . i have a 09 evo 290 t2 . i just took the bike out of storage as its been packed away all winter clean oil clean coolant . fuel was took out of the bike before i stored it . anyway all was fine one day about a month ago after sorting the bike out . while i was playing about in my fav riding places . i noticed the fan not coming on so thought right thats it anyway the bike overheated i stut it down and called my local bike mechanic . new stator and new rectifier later and 2 new michelin tyres . got call form the local mechanic to say your bike id fine come and collect it . i did went for a ride with the bike right away and still no fan it was still not working . after the guy telling me the fan comes on now its fine . and i noticed now the bike seems to be advancing i give the throttle a blip and it takes ages for the bike to get back down to idle it is not right it never done that before . anyway got to take the bike back on tuesday for him to fix it this time .. also on another note . i have a flywheel weight on my bike whats the noticeable difference if i do take it of cheers