by JoeMaico » Tue Mar 22, 2022 4:19 am
Sounds like Pipe Bang. Do a search for two stoke pipe bang and you will find some articles on it. I like the one from PowerCDI. Many discussions about it in other two stroke dirt bike forums as well. Personally, I have it on my 2016 300 RE and I don't do anything about it. It is only shows up after I have been on it for awhile and I cut the throttle and let it motor along at just an idle. Twisting the throttle always cleans it up in short order. It never shows up when you first start the bike and it is warming up. Nor does it show up after the bike has been run, shut off for awhile, and then restarted and allowed to idle. I always equated it to secondary ignition of unburnt fuel near the header, because it probably had glowing hot carbon deposits after getting on it for awhile. But, Fabio (PowerCDI) disagrees with me. I have read some of his other articles, and I always thought he was a knowledgeable individual on the subjects he discusses.
joe