Thanks for the reply's. The 340 and one of the teens has the 650 eddy. The other teen has the 390 holley. All three motors do the same thing and the only thing common to all is the ignition system. The issue is at idle or slow cruise is is seems to die for a split second. I have re-gapped spark plugs on the 340 and will be going out for a test drive this weekend.
