just converting my mc21se to pre-mix when i removed the oil pump i found an extra oil feed from base of pump to drive side main bearing and only one oil hole from transfer port other two mains have two holes, mi mates mc18 does' not have the extra feed from the pump but has two oil holes to all three mains do i need to drill an extra hole as per mc18 or will it be ok whith one hole without the pump and on pre-mix. can anyone help please.