engine management light

[miltos]

Hi,been away during winter...so want to ask:Tiger 02- suddenly the bike revs high at 2500+ rpm then after some seconds back to normal 1500/1200. EMLight comes on!!!Thouhgt oh fine...next day with management light on driving to garage to check out. Engine off said to the guy about the problem,turn engine on....light Off!!!!!!Got home light off.
Next day ready for work---light On!!???whats going on??

Ps. Tighten chain but for some reason doesn't stay tight after a while when riding...
Never had such problems before---all at same time??!!

Any help?