I don't wanna give you misguided info, but check your spark plug seals. When was the last time you replaced those. You might have fouled your spark plugs. Change seals get new spark plugs. If that doesn't help, I think you might have a bad piston ring or bad head. These are just some suggestions. I hope someone with more knowledge chimes in.

I'm oohxchun bro. When his f22 did that, we tried changing the plugs and all seals, didn't work for long. We just decided to swap the motor out completely. A comparable swap is the f20a dohc motor or another f22a. Straight drop in. If your motor has a lot of mileage consider that option.