This was a freshening up of the engine that was in there already. After the tune up we had 6-7 no problem trips. This problem surfaced after she had been running fine for a while and even then it does not occur every time. In fact the engine ran perfect all the way to our destination that day (about an hour run) and then started the problem on the way back (about 3/4 of the way back) so strange. Thanks for any input. Don Jr