so one of my friends back pack blowers broke its mounts off the engine, he had it repaired under warranty. but the shop took the old engine apart to see the piston. seems these red max engines need to run 93 octane and if you use 87 the piston gums up and the rings stick to the piston causing piston slap, that you could hear.
he showed us the piston, the rings were stuck to the piston, the whole piston was black under the rings on the skirt. its now sitting on the shelf of shame at the shop parts counter. were theres pistons with dented tops and cracked skirts. he said another few week and the piston would have blown.
so today we sea foamed all 4 blowers, took the air filter off fogged it in the carb then flooded it out, waited fired it up it smoked but not a whole lot, so i pulled the plug out, and flooded the cylinder let it sit, fired it up and the smoke show was on lol.
then we pulled the muffler off one of the older blowers and the piston was nice and clean and the piston slap was gone, little engine was screaming like it was new, with some added power and throttle response.
this was the small engine and carb and tb cleaner sea foam in a spray can i used, sh it works great!