I installed the euro header and muffler to play with the O2 sensor on the header.
Turns out the OD of the header is ~1 mm less than the OD of racing header_with_bomb
so I had to use the muffler that came with it.
Said muffler looks like a carbon copy of the aluminum racing muffler, except for being made of steel and chrome.
The internal baffles and baffle penetrating pipes look identical.
I hooked up a digital votage meter to the O2 sensor and
ducktaped it onto the bars so I can read the digits while riding.
- header diameter and pea shooter won't affect air fuel ratio of the charge,
especially around low power demands, hence the measurements should be
findings so far:
- my current idle CO value of -4 still has the bike idle rich
- everytime you close the throttle you'll run rich (probably as zero throttle idel mixture cuts in)
- a fuel mapping with all fields set to -7 except for low throttle/low rpm (-6) still runs rich everywhere except for
STEADY 1/8 throttle and lower rpms. edit: WRONG: checkout subsequent posting #21 http://www.thumperta...2#entry12497115
Exactly the short-shift mode yu'd use when you are afraid that some cop might bust you because of your exhaust:
very little throttle changes + shifting early, then you'll actually run lean.
- as soon as you increase throttle it'll jump to rich
- as soon as rpms climb into mid regions (w/ throttle unchanged at 1/8th) it'll turn rich
- every kind of short full throttle manoever in last gear will run rich
- only when you go WFO + step on the rear brake to keep rpms medium you have a chance of seeing lean combustion together with knocking.
So the ECU must have quite some acceleration enrichment (messing up any measurement).
At this scary "all minus-sevens" map you still are mostly running rich.
But with -6 in the lower left corner you'd be cruising at 50 mph running lean (only at 1/8th throttle, mind you)
- further experiments necessary
- maybe the header + muffler backpressue make the bike run rich? (sounds unlikely to me)
Except for applications where one might WFO through deep, gooey mud (keeping rpms medium)
one can only PowerTune the constant speed cruising mode to not run be rich.
All maps that are floating around are rich, everywhere.
I think YAMAHA did that to protexct the engine.
- I'll search for the richest CO value that'll gives a non rich idle mixture, to not mess up readings so often.
- I definitely need to do some freeway testing. I need a climb where I can go WFO w/o accelerating.
Anyone got an information source describing how 1/8, 3/8 and 6/8 throttle are to be interpreted?
are they measured ate the throttle grip?
Or calculated from the throttle opening value of the CO adjustment toll's monitor mode?
Edited by WRF-Rowdy, June 26, 2015 - 06:11 AM.