RE: Saito FG-30 gas troubles
But the oil residue on the valve stem when you use Amsoil Dominator at 20:1 is like a steel coating and extremely hard and will cause the exhaust valve to stick. This hard carbon also forms around both sides of the ring. It is almost impossible to get off. (Will require disassembly of the engine)
Use of an oil intended to be used at a ratio closer to 20:1 and the carbon formation on the valve stem is softer.
If you use Pennzoil aircooled mineral oil at 20:1 the smut on the valve stem will wipe off the valve stem with a Q-tip through the exhaust port. The ring area will be clean.
The Evolution oil they recommend is Morgan's Synthetic Kart oil that has been repackaged for Horizon. It would be better than using the Amsoil.