1997 Honda 300 trx throttle problems

This atv is snorkled...I went to deep, not over the snorkel(just above the handle bars), and it shut off. Well after i got it up and running and after changing the milky oil(crankcase vent tube was broke and didnt know it), it will not go to full throttle in gears 1-4. It will back itself off once it hits so many rpms. I guess it doesnt reach the specific rpms in 5th gear cause it dosnt back off in 5th. I figured it might be the rev limiter in the CDI box, so i changed it. It was not the CDI box...any suggestions????