RE: FUNJET
poorwboy,
Iwould guessthat you are flying at 100 MPH not 90, but either way...lets get past that and get you to go faster.
The suggestion above to go with higher volts is a good idea, but there will be a big jump in amps so as USUAL; you must go down a little in prop size.
On a good 4S that can handle 50A with ease try APC E 5.5X4.5 up to maybe 5.5X5.5 using a wattmeter to write down Amps, Watts
See what the Amps, and Watts are right now and if your motor is overheating now or not.
Run a full size heat sink for the summer.
50A ESC is a good choice.