I'd call Hilborn,they were always generous to me when I had a problem,,,,? running alky or gas..whats the fuel flow rate of your pump?alky as just a guess0.65 main pill-hi speed 0.70 set to open at 58lbs...but thats based on 1.58 gpm pump -bigger pump-would mean bigger return pills....start the barrel valve setting at 25%....longer stacks more torque