Just bought this motor. Starts, idles, trolls great. Twist the throttle to go wide open and it'll take off fine until it hits 1/2 speed and then bogs down. Pull out the choke, it runs much better and will run almost reach top end - still sounds like it could go another 1000 rpm's though. Put it back down to trolling speed and I have to push the choke back in otherwise it'll quit. What would you guys try first? Thanks!