HI, I have a YS 110 with about 3 gallons of fuel through it. It ran nicely last season but it doing something different this season. I am using an idle up switch on my transmitter set to about 300 rpms over idle. At this setting the engine will surge in rpms,then sag to near idle and surge up and down several times until it finally quits. It does this a little at idle but not nearly as much. So my question is what do I do to get this higher idle to remain constant without the surging? I am using 20% Coolpower and an OS type F plug. Thanks Ben