1999 DT150 RPM issue

[windsoreight]

Hey guys I just swapped my old faithful and reliable 1987 Johnson 140 for a 1999 Suzuki DT150 2 stroke. The motor has good compression and ran great on the stand. On the water the motor wouldn't go over 1200rpms. If you work just the throttle lever it will go to 5K. With the shifter only 1200. I was pulling out of the canal after checking the plugs and the motor started to run rough and the rpms picked up. So I hit the throttle and the boat took off, planed out and reached a max of 4K. It then dropped off plane and went back to the 1200 max rpm. The motor runs smooth, the primer ball stays hard, no alarms going off. I have a complete parts motor too. Any advice on what to check? I do get the smell of gas from the engine at times but no leaks and the plus look great. They are not fouled and have a nice color to them. Thanks.

[windsoreight]

Also am I supposed to have a check engine light. I am running a standard control and have the multifunction gauge. I haven't seen a check engine light.