You need more weight. In my experience, weight in the front tends flatten the surf wake (unless you have a ton of weight in the boat). Try this. KGB full, and the full hard tank on the side you are surfing plus a 400 lb fat sac in the same rear compartment. This will be aprx. 650 lbs in the rear corner and enough to throw a killer wake! I can surf this wake all day with only 2 people in the boat. Try speeds 9.4-10.5. Verify with a GPS! 9.8-10.2 MPH has always been the best for me. 10.2 if you have a lot of people/weight in the boat.
The wake on the port side will always be cleaner b/c of the prop rotation. If you have people in the boat, put them on the same side of the boat. Nobody in the center or on the WRONG side of the boat. If you have too many people throw them on the same side floor or in the bow!
The surf wave is very respectable. It's not the biggest, but it has a lot of push! I like it better than other MC's in the lineup. If you can't surf it, it's an ability and/or equipment problem