Mailman Q: Gary , I really am curious about your testing. I’m interested in your views.
A: You're crazy Bob
1. Did the use of your O2 sensors provide you with information that resulted in any noticeable performance gain?
As part of an organized tuning effort and after some time spent learning what they do (and don't) provide they are helpful. In several ways I'm not there yet on the process. like 2M sez there's a lot to learn
2. Did the O2 sensors allow you to expedite the tuning process?
A: Yes
3. I know Madness is a pretty hot rodded 650 already, do you think there is still room for performance gains and still have street riding usable powerband?
I'm guessing madness is pretty
close to the ideal between power and streetable. (see below for caveats)
The Spanish Inquisition wants to know!
Tuning an XS650 on the street is tough.
Tuning is hard on an engine, full power runs to redline tend to use up an old school mill like this. This bike has seen some hard use.
I have several dings against me.
Unknown history. Uncertain what-all parts are in the motor.
One cylinder is weaker by about 10-15 lbs R180 L165
This tach has always been suspect, pretty sure I've gone past redline (too many) times.
It's a pain to swap a stock tach in, I did do that once, several budget electronic tachs, experiments have also been questionable.
I'm not very organized or consistent, always wandering off on another tangent. Changing a couple things at once. (changed sprocket
and needle setting in one shop session yesterday.
Speed limits and police make doing this dicey, I had one conversation with deputy Dan already this year.
(on the EBR, near comical in how THAT went) Just been lucky a couple times since.......
Really; an accelerator pump.
That was also kind of a hint to someone I know that's holding
VM34s are cheap "performance" carbs, not the crème de la crème. An accelerator pump set up is probably the best way to get a balance between decent fuel economy and that satisfying rush of power when you grab some throttle. (short of a closed loop ECM, fuel injection and mapped advance curve, anyone considered
that rabbit hole, Jim???)
My last couple tanks have been showing 50MPG, I run premium. and with the 18" front wheel I'm prolly 5% off on the odometer.
This was possible even with those way rich mains and testing, cuz 90% of riding is on the needles not the mains. That run to Ozarks and back last year with 65-70 MPH highway speeds and 200 mains saw me down in the 30's MPG, one fast freeway tank, may have had me down in the 20's!
Should really swap the borla's back on for a test run, I suspect these mufflers are a bit top end limiting. There goes another shop day....
This O2 set up is bulky, takes away from the bike, got a couple things I could do to improve that yet but it won't stay on the bike for long periods.
Tuning is a time sucker, even with the O2, a day slips by pretty quick. There's always other projects need doing.
How spot on does it need to be? how much tuning time is worth doing? nebulus concepts.
Was out back to back yesterday on the XS and the EBR, I'm getting old, that EBR is a handful, things happen REALLY quick. Overall the XS is like a comfortable pair of running shoes. And more fun on "rough, tight" Wisconsin back roads.