Re: 100:1 Mix
Tom I think the muffler was somewhat clogged with the carbon that the opti2 loosened up. By you switching back to your regular oil mix the heat of the exhaust made the muffler slowly burn away the sludge carbon deposits left from the detergent effects that opti2 had on your engine. That would explain the gradual improvement in the performance of your engines output. The E85 Ethanol is not suited for use with the Opti2 oil. I read this info I do not have first hand knowledge of this.