Plug chops are (in my opinion) an essential way of setting the engine up.

Most of my hard riding is done on the track, so the engines must be set to run under those conditions. this means that max rpm is never held for more than a second or two at most. Using what would be safe track settings on the road would probably lead to engine failure.

An engine on the track is either under acceleration, or braking on a closed throttle. You're never holding the throttle constant for more than a couple of seconds.

On the road you're gonna be stuck in traffic, chugging down the high street or flat out for miles on your favourite stretch of tar trying to dodge those troublesome police men.

Setting the main should be done starting from rich. You can get a feel for what's going on inside, by the rate of acceleration from say 7~8 grand up to the red on WOT. If it won't rev out and won't stop smoking then you're probably too rich. Wild rpm (13,000), but bugger all torque to get you there means that it's way too lean and will nip before you get up to speed.

I do the main first, then try to dial in the bottom from closed throttle low rpm. This would be the slow jet and air screw.

Once it'll pull off the bottom nicely, and rev out at the top I'll then go about fiddling with the needle to clean up any mid throttle issues.

If I find myself going richer on the needle clip then I'd start to consider a drop in main jet, especially if it lost some rpm. opposite is also true of course. The straight diameter has more in common with the slow jet and air screw, so you might find a fraction of a turn here and there might also be necessary to get a smooth transtion.

What I like to end up with is a weapon that has max power and throttle response all through the range, but then from here I'd just sneak up a main jet size or two for protection in case I get carried away. I also set my personal bikes up at night 'cos it's a bit chillier (sometimes below 20 deg C) so that I don't have to hover my fingers over the clutch on my way home through the jungle on those particularly fresh evenings.