Ok now that I have your attention. This is going to be one of those rare rant on a vendor, a good one. Let me tell you about my problem and how it got fixed. Every Time I got up in the rpm and went for the shift as soon as I released the throttle I got a backfire. Annoying to say the least, even embarrassing at times. Wife hated it I hated it. The culprit here is simple, oxygenated air getting into the exhaust stream where there is still enough hot gases to cause ignition. The problem is finding the leak and resolving the issue. At this point I should tell you that there is no stock exhaust on the slingshot at all. I removed the entire system and sealed everything, real good, as I examined every piece as best I could upon re-assembly, I even milled the header to head flange .045 to make it flat. I purchased 1320's composite gasket set and installed it. A copper base hi temp sealer was used upon all assembly steps on every place there was a joint of any kind. Go for a test and bang, back to the shop. Remove the header and replace with stock cast iron manifold, seal good as well. Go for a test drive and bang, back to the shop. Now the 1320 header is eliminated as the leaking piece, so it has to be after the header somewhere in the aftermarket exhaust. Here comes the vender, @Jeff Welter. He confirms my suspicion of the air leak, has me take some pictures of the first pipe (the first after the header that has the muffler in it, and the second pipe in the system. After a few emails and remembering that mine was possible the first 2017 to wear the dual exhaust Jeff tells me he will send out a new primary and secondary pipe. He does just that, plus a new crush ring and the new tail pipe support piece. After getting over some PTSD crap I finally get the chance to do the install. On the test drive I wind it up a little and shift and no backfire, so then i wind it up to red line (maybe a bit past) and shift, still no backfire. Wife and I are happy that we can ride without all the backfiring and causing us to be nervous and others to get pissed off at us. So far I am just in awe of the service after sale that we have gotten from Jeff and Angie. If anybody reading this is thinking of getting after market exhaust I would strongly suggest you get your exhaust from @Jeff Welter. If you think it may be to expensive think about the quality of the exhaust it self and the service after the sale that you will get from these fine people and an outstanding company/vendor.
Off the soap box, would be out riding but Oklahoma is getting hammered by storms, again.