5400 seems awful low. Look online at what that motor should be running, but im going to say go down a pitch.
As stated the benefits of a JP are numerous, but not your only option. Probably your best, but not only.
Several things to try. First you gotta have a starting point. Thats the prop to pad measurement. Then what RPM's that motor should be putting out, then after you figure those 2 out, then adjust motor height and prop pitch if necessary. Im sure one/both will fix most of your issues.