PP256s intermittent plasma cutter performance

[John71a]

In trying to cut thicker metals (1/2-3/4"), my torch goes on a few seconds and then off a few seconds, piling up surface dross and rarely fully penetrating at 62 amps on the readout. I've gone up to a much more powerful compressor with 12.5 CFM @ 90 psi and regulated down to 70 on the unit per instructions. I have pulse off, 2t on, etc.

It keeps burning up the ceramic cap, nozzle and electrodes, even when using the wire standoff.

Is there something I am missing? What causes the torch to stop and start continuously?

It has the Traffamet S75 torch