the service manual and bikeboy state to set the CO levels with the airbleeds, and to only use the software CO trim if it is out of range. the airbleeds also change the idle RPM. the first time i tuned the bike, i leaned it out so far that the bike was idling at 2500 RPM. what is the procedure to set the idle speed then? do you set the CO trim to zero first?
my approach was the following: use airbleeds to set the idle speed @ 1200, and use software CO trim to adjust the burn rate (AFR).
LM2 power requirement:the O2 sensors require a decent amount of power to remain heated. LM2 comes with a cigarette lighter attachment. a car battery can be used, but i wanted an instant AC/DC solution rather than worry about car batteries.
LM2 manual states the power requirement as "Dual Channel 8-14 Volt / 4 A (max, 2 A nominal)".
initially i used a 12V, 5A rated "medical power supply":
i encountered a problem where sensor1 would produce an undervoltage error, and go into warmup mode. this would result in about 20 seconds of no data. either the power supply is insufficient, broken or LM2 is more power hungry than stated.
i switched my setup to two 12v, 4.15A intermec power supplies connected in parallel:
i have not experienced the power failure since.
there are a few options here. you can use a bench power supply, or any laptop power supply that is 72W+ and then use a buck converter to deliver 12V. in general i don't trust chinese specs on cheap brands, especially with higher rated power supplies.
warm up:the ECU has two tables associated with fuel adjustment and "warm up".
one is Engine temp:
graphed in Fahrenheit:
the adjustment factor of 1 is at 75C or 167F. any hotter and the ECU is pulling fuel (leaner).
the second one is called Fuel warmup:
my understanding: rows are engine temp in C. columns are marked "seconds" in the XDF file. i think that is incorrect. that would mean the correction factor of 1.0 at 75C would happen after 2500 seconds (42 minutes?). i doubt it. bikeboy states:
One very important thing to know about the 1.5M ECU is that it runs rich for the first 3,000 rotations every time you start the engine after turning the key or kill switch off and then on.
this is a 59M ECU but it could still apply. the columns could be number of rotations. it seems weird to have columns for 4,8,16,32,... rotations. why such precision at early stages that the bike turns on?
cold start:here's the graph of a cold start. the cylinders are synced, however they have different AFR. you can see sensor1 (blue) going out of service due to the power issue stated earlier.
right around 600 seconds (10min) is when the engine temp reached 65C.
i recorded the engine temp manually by setting a timer and writing the number down on paper. later i matched my timed recording with the time stamp in the O2 log.
it looks like i started adjusting the airbleeds around 400 second mark. 680 second mark looks like a restart. any time the bike is turned off the AFR starts climbing (lean). right after restart, the bike runs rich for a while. 750 seconds i may have used the fast idle knob to increase the rpm.
restart 1:here's a restart after i adjusted the cylinders to be ~.2 of each other. the engine temp started at 87C (189F).
here it seems like the bike leans out after a minute and then settles back down after another minutes.
restart 2:here the bike was at operating temperature. it looks like it starts out rich. leans out about a minute in. and then settles down at the 2 minute mark. sensor1 (blue) had loosened ~ 60sec mark at the exhaust bung, so it was reading leaner.
restart 3 & 4:i have two restarts here
restart 3: CO trim = 6, red = O2 sensors, green = engine temp
restart 4: CO trim = 4, blue = O2 sensors, yellow = engine temp
if i was to conclude anything, i'd say wait minimum 200 seconds on a warm restart before making adjustments.
making adjustments:here things got a bit interesting/frustrating.
1) i was only able to make CO trim adjustments in guzziDiag. I tried JPDiag and IAWDiag, but the settings wouldn't hold.
2) when you modify the CO trim, the ECU (or guzziDiag?) slowly ramps up/down the fuel. it takes about 20 seconds. then you have about 10 seconds to read the value. at 30 seconds it rapidly restores back the previous value. i.e. you start at CO=5, increase CO to 10. after 30 seconds, your actual CO value is 5, even though the software will show 10.
3) to set the value, you need to [OK] the value during the 30 second "test mode".
a visual demonstration:
CO is changed from 6 to 3 (red), and 6 to 4 (green). notice how the AFR remains flat only from 20-30 second mark.
example 2:
effect of CO trim on AFR:in the previous 2 examples, we see that a change in CO from 6 to 4 results in a change of .3 AFR (.15 AFR/CO). 6 to 3 results in delta .5 AFR (.17 AFR/CO). 5 to 0 results in 1.15 (.23 AFR/CO).
here's another experiment:
yellow - 0.14 AFR/CO
orange & blue - 0.16 AFR/CO
green - 0.18 AFR/CO
red - 0.19 AFR/CO
finale:i set the CO trim to 5 to end up with an AFR of 12.8x. the bike felt sluggish at low RPM and i was getting pretty bad decel pop. i increased the CO trim to 7. there's a noticeable power increase at low RPMs. it rides well. no decel pop except after a long trip when the engine temp is >200F. there's a hint of it on short trips with engine temp < 190F. with CO trim 7 i've gotten an average of 55mpg on 3 tanks. i will increase the CO trim to 8 to see whether the decel pop is eliminated.
is that a cheap method to tune the bike? decrease CO trim until decel pop occurs at engine temps >200F, then increase until it's eliminated.