In a recent model magazine it was explained the difficulty 'choking' a gas engine in order to prime since the choke butterfly has a noticeable size hole it was recommended to 'remove'the choke butterfly and solder the hole shut. I was informed of this modification from Mike at RCS a ways back and prompts me to inform all that removal of the single screw that holds the choke butterfly in place is easy to remove however after the hole is filled in the choke BF you simply screw it back in place-----> now there is a potential problem!! once the screw is removed it DOES NOT necessarily stay put and guess where it goes if it comes loose ? Yes thats right the engine INJESTS/EATS.. the screw and that is not good.[:@]In my case Mike at RCS rebuilt my ZDZ and I remain most appreciative but had I been billed go figure the cost of a new cylinder and piston Etc. My suggestion would be to fill the hole in the butterfly while it is( still in place,) using JB weld taking care when applying it to fill the hole. I strongly suggest if you have removed the butterfly that you use locktite red to ensure that screw does not come loose with disastrous results for that expensive Warbro carbed gas engine.