I have a Troy Bilt/ Briggs and Stratton 6.5HP Power Washer which loves to try to pull my arm out of the socket when it kicks back during starting. New spark plug, new air filter, new carburetor, pulled the head cleaned out any carbon, new head gasket. My question is would a higher octane fuel have more resistance to kickback. or just cause hard starting. I was thinking the delayed ignition of a 91 octane may kick back less than a 87 octane. Also unit is very hard to start once hot.