110 pump gas?.. where you find that at... i have 19cc domes on stock crank no timing advance.. the timing doesnt do with the crank.. but it does affect runnin pump or race.. depending on your elevation i would run 19cc thats borderline pump / race depending on your elevation.. i run straight race gas at 500 above sea level but i can run 50/50 pump race... i have a timing plate i need to add so i just keep my motor on straight 115 so it gets used to it.. besides race gas has lead and sheeeee's love lead!!