I AM TRYINGTO RESTORE A CBR 600 FK ( NEARLY FINISHED) HAD TO REPLACE AIR BOX OLD ONE CRACKED. ANYWAY THE NEW AIR BOX HAS AN EXTRA HOLE THAT LOOKS LIKE A PIPE CONNECTS TOO? THERE IS NOTHING TO CONNECT TO IT !! IS IT TO REMOVE CONDENSATION IN AIR BOX ? I HAVE NO CLUE . THERE IS A DIFFERENT NUMBER STAMPED ON IT THOUGH . MN4 30 ON THE OLD AIR BOX (NO HOLE) MN4 74 ON REPLACMENT PART ???? CAN ANYONE ENLIGHTEN ME ? OR SHALL I JUST TAPE UP THE HOLE. STUART

 

I'm by no means an expert here... but if the airbox "drops in" and doesn't have any wierd issues fitting in, then yeah, cover the hole up (suggest some plastic or something more permenant than tape) and rock out!

 

[sm=groupwave.gif]i agree-

 

The only thing I can find that matches both MN4-300 and MN4-740 is the sub-case (bottom piece) of the air cleaner case (17220-MN4-740). Both numbers are listed for the same part which should indicate both are acceptable for use.

It appears there are two holes for breather tubes toward the front, and a third near the back left for the 'air suction hose'--but I cannot discern whether this hose is supposed to have a love connection with the 'air suction valve'. Apparently all 600F models have this valve--check around for any missing or loose tubing.