Thanks for the reply. Yes close hauled trying to tack to the opposite close haul, approx. wind speed 10 to 12 knots, boat speed approx. 3.5 to 4.5 knots. Standard sized jib 110% or so. Clipping along nicely on a closed reach with the wheel 5 degrees to windward, bring her up to closed hauled to turn through and nothing, wheel all the way over and she won't come about. Ended up bearing off onto a run and then things really got interesting (but that's another subject).
The next day winds were lighter, 5 to 8 kts. Made sure the center board was down and the rudder tied off (down position). Put a reef in the main and furled in the jib in to a standing tri-sail. Set off on a close reach, boom in tight to the center, turn to wind, same thing! With enough speed I could just barely make it around (both tacks) but half the time I had to actually start the motor to get her to come about (motor is linked to the rudder). I've sailed dinghies for years so I know how to come around and what is supposed to happen. I think the center of force is too far forward and a possible cure is to rake the mast back further to aft, just not sure how big a difference it would make, I suspect its a combination of things; inefficient mainsail due to missing battens together with incorrect mainsail trim (dam wheel steering, can't access the main sheet), rudder not locked down tight enough (not sure if it can be pinned in the down position), maybe the vang isn't tight enough, incorrect rake on the mast? The sails seem to be in good shape save for the lack of battens.