Iím newer to the js440ís. I rebuilt the bn44 round body carb and replaced all the gaskets from the motor to top of carb. The 440 is stock other then replacing the rubber and metal baffle between the exhaust and water box with a straight piece of rubber exhaust hose. My question and help Iím asking for is do I need the spacer in between the motor and manifold? I cannot get the carb to idle or even tune in at all. I have rebuilt and tuned several bn44ís on js550ís just canít get this one..... it also has the stock choke should it be replaced with a primer? Anything will help! Thank you