I tapped the hole and then threaded a set screw and a jam nut with a little silicon on it. Works just fine. Scott Mueller DMCNEWS 002981 DOA 5031 Subject: Re: [DML] DMC How are the fuel injector suppose to work in this system? QUESTION: My next related issue involves the plug that covers up the access hole for the aforementioned 3mm Allen wrench is missing. --- Does anyone know what this plug looks like? Judging from the hole it seems to go down straight (no threads) for a bit and is then threaded.