Originally Posted By: Trav
He is pulling your leg. Tell him the stuff you buy uses detergent like Palmolive not the stuff with dawn type detergents in it.
Any oil can foam when it gets whipped up, pressure system or not if the oil doesn't have sufficient anti foaming agents.
BTW. Nothing wrong with the Rotella, its a good oil in small engines. Over filling can cause foaming as the other poster said.
Rotella works well in OPE because it is a robust, beefy HDEO. But, the OP didn't use Rotella, he said he used Formula Shell, Shell's PCMO, a different oil altogether.
We live on a farm, and have a few Honda GX engines on our equipement. A Honda lawnmower, a Honda GX engine powering our Troy-built Rototiller, and a couple of GX 390 engines, one mounted on our hay elevator, and the other on our go-kart. I have used the Rotella Triple Protection 10W-30, then T5 10W-30 in them with no issues.
This past year, I used Mobil 1 HM 10-30 and TDT 5W-40 because I wanted to run a full synthetic. I'm liking it better than Rotella, the engines are running smoother and quieter than with the Rotella.