It doesn't happen to my motor what you described O ' donnell did to yours'. The main bearing and crankshaft in my motor rusted badly while on this stuff after two weeks. It was a brand new motor. This stuff runs real hot, motor bogs down after a couple of tanks. It sounded rich with lots of smoke but I am still burning plugs.My motor will quit for unknown reasons. Tuning most of the time. Problem went away after switching fuel.
Originally posted by Top Gun 777
I have been involve in this hobby since 1976 (13 years old) and most of my life was running FAI fuel (80% methanol and 20% castor). Then I come to RCcars and here I tryed different types. The best fuel is defenetly O'Donnell. It doesn't leav any residue nowhere-cranckshafts are always clean and no rust or other spots, even if I leave engine without washing for more then month-I never clean my engines.
About build up of varnish on botton and top of piston-vernish is engine killer. It works as insulation and don't let survaces to cool down. They have to be removed as they start build up.
Top of the piston and combustion surface on botton must to become dark brown on new engine after 8-10 tanks and it should be not a build up, it just very very tiny layer. From most of the fuel I did indicated real build up and after I have tryed O'Donnell I don't have this any more, this is why I don't clean my motors-simple no need it.
It is very easy to see the difference between "good" or "bad" brown build up-"good" is shiny and "bad" is not. "Bad" build up will come out easy with just by trying wipe it off by finger and "good build" up will not come out at all, unless sand paper used.
Edward
Edward