Be care with home built exhaust mods. I have built many bikes from scratch and this mod will affect performance and I suspect negate the warranty. The “ pops and crackles” are from a lean running condition. If you modify the exhaust; you should look at the after market option or options that are yet to come. This bike was mapped to run with the stock exhaust hence you need to redesign the rest of the exhaust , remap the power unit, change out the air filter. It is your bike and engine. The ECU, exhaust and air filter and all the rest were designed this way for a reason. That is wat you always do the pipe, carb or FI, ECU and filter at the same time on modifications accordingly.