bernard
.060 Over
2014 Roadster. It sounds OK at idle. Off idle to about 2500 rpm there is a distinct miss. It starts smoothing out at 3000 rpm and runs strong and smooth to redline. In addition to the miss, there is an extra noise coming from the exhaust pipe. The pipe is a 3 into 1 baffled megaphone (Carpenter). The noise sounds like someone tapping the pipe with a small hammer, kind of metallic. It's most pronounced between idle and 2500 rpm. Above that it isn't noticeable probably due to the rpm and exhaust note. If it was just a miss from misfiring, I would think it would affect the full rpm range. I tend to think the tapping noise is coming from an issue in the engine amplified by the megaphone exhaust pipe. So I think it isn't a tune issue, but a mechanical issue which will probably require a teardown. I can start with the basics - compression check, check plugs, wires, connections, etc. But I think it has a mechanical problem in the engine. I'm all ears if you have opinions or been down the same road.