Yep thats the esc. in the end i did manage to unblock it with a small drill bit. i had to use
quite a bit of force, so im not sure weather i would have damaged anything, but both sides
were blocked the same.
the esc looks almost brand new so im wondering if it was a fault when manufactured and its
never actually worked, i would say at a guess that it was blocked with epoxy. i have pumped
a fair bit of water round it and there are no leeks and it all seems to be working ok but i would
advise anyone with this esc just to double check for this fault to be on the safe side as it was
causing no water to be able to pump round the motor either.