Originally Posted by carlesonra
Thanks for the post. My plugs are dual electrode which may be make a difference in read. That said, compared to your Autolite picture, my GS is showing lite grey even inside the plug, Based on the posts I have read here, I may be attempting to fix a normal burn as I have no spark knock or throttle issues with this machine; my old dirt bike days may be saying it is lean only in my mind. So, if it ain't broke don't fix it. The K&N may need another look though.
Thanks to all for responding to my question.
miscellaneous other motorbike
Remember, reading plugs these days is different than from days of old when we had tetraethyl lead in our fuel. Also the old fuels were not blended with oxygenates. Also, many dirt bikes were 2 strokes...different animal altogether.
As for megaphones, (reverse cone megaphones actually), cam overlap and Manx engines on old Brit bikes, they were dealing with completely different flows and had no EPA to deal with. Also Hailwood, Agostini and the boys were often limited to engines half the size of the current boxer displacement.
Today, engines must comply. To do so, the state of tune is much milder, compression is lower, bore-stroke ratios are different, EGR is prevalent and we have engine fueling managed by computer, not the needle position, throttle valve cutaway and main jet size of the old Amal or Dellorto carburetors.
Those days are gone unless you tear off the EFI and install carburetors.
Aftermarket exhaust and fancy air filters do little more than lighten your wallet. If you want big performance, the boxer is not where it is at unless you're thinking turbo....
To extract meaningful additional power from a boxer, you'll need major engine work. To improve driveability and engine manners, follow roger04rt's suggestions. His work is backed up with charts, AFRs and other sophisticated measurements that are meaningful.
When you have spent north of $1000.00 on a fancy exhaust, your butt dyno is already biased towards at least 10 BHP gains before you even start the engine.
Installation of fancy air filters carry slightly less butt dyno increases.
Want a few free HP from your boxer? Change oil viscosity to 10w-30 or 5w-20. You gain several HP by reducing rheological losses.