Removing the snorkel has allowed more air to get to the engine.This means the mixture is weaker. For the short term there will be a performance increace but its a falsehood. As a leaner mix gives more power, but!
The leaner mixture will cause higher piston temps and shorten piston life by quite a margin due to the expansion increasing wear. Depending on how you ride, in the extreem you could hole the piston.
Lifting the jet needle clip one notch may compensate and keep the motor happw with a bit of extra go. Stock is best though.