Got it even without the picture ;-)
Funny to notice the whole packaging is the same, only the switch is not present and there's a cover on it. I believe that symplifies the number of references for the manufacturer.
I really wasn't trying to be pedantic (or to offend), just documenting the headlight issue now that I've modified the system to a configuration that's pleasing to me.
I agree with you that it appears Suzuki chose the absolute easiest solution to comply with the U.S. government headlight requirement. I guess the actual number of Bandit 400s bound for the U.S.A. was a very, very small percentage of Suzuki's overall worldwide output for the bike. This situation didn't warrant a real change to the bike's wiring harness (i.e. adding a headlight relay) which would have made production more expensive.
About the timing issue: where you able to adjust the microsquirt settings and get a smoother engine? Even if you did not have a chance to run it yet?
Yes. I haven't ridden the Bandit around yet but I've done a lot of idle-speed tuning and testing. Now the idle is normal/tunable/controllable.
My mistake with the basic timing setting, using the wrong crankcase timing mark as the basic timing had the effect of making the bike's idle ignition timing 15 degrees too advanced which combined with my use of 10 degrees of additional timing advance (a perfectly normal amount for a basic idle setting) caused the engine to idle too high, about 2,300 RPM.
Using the wrong timing mark gave me 15 degrees of timing advance, but because I was
unaware of this situation I was
adding another 10 degrees of timing advance as I attempted to tune the Bandit's idle setting. This was not a good situation: I was thinking I only had 10 degrees of timing advance BTDC (before top dead center) at idle but the real result was a total of
25 degrees of timing advance at idle, which made the bike's idle impossible to tune.
Until I figured out my mistake there was nothing I could do to reduce the idle speed below that level (2,300 RPM). At first I thought the Bandit's intake tract had an air leak somewhere that was allowing in too much air, which is a common cause of high idle speed accompanied by lean air/fuel ratio readings on the wideband oxygen sensor. This theory made sense to me (seemed reasonable) because these were the exact symptoms I was seeing.
In an attempt to diagnose which cylinder(s) were vacuum-leaking I hooked up my Carbtune synchronizer unit to the vacuum port on each Mikuni carb-throttlebody, expecting to see a wide disparity in vacuum between (one or two of) the Bandit's cylinders but instead they were all just about equal and pulling a decent amount of vacuum. So I knew the cause of my problem had to be something else.
I was sitting in my chair next to the motorcycle, feeling completely lost, when the realization hit me that the second "T" mark on the crankcase (the one with the rectangle around it) was about 15 degrees further around in the direction of engine rotation which meant that it was the correct mark to use for the bike's basic timing setting. This might seem obvious, as in "how could I have possibly missed the meaning/implication of the fact there are
TWO timing marks on the bike's crankcase?", but I'm living proof that it's possible to make this error...
So I added in the 15 degrees to the Microsquirt ECU's basic ignition setting (changing it from 270 degrees to 285 degrees) and I started the bike up. The Bandit was already warmed up from my previous idle attempts so it settled into a stable idle pretty quickly, but this time it stabilized at 1,600 RPM with a very nice 13.5-to-1 air/fuel ratio showing on the wideband oxygen sensor gauge.
A quick test with the timing strobe light (temporarily removing the 10 degrees of idle timing advance so the Microsquirt ECU would only be using the basic timing number, 285 degrees) showed that I had the "rectangle T" perfectly timed.
Now I can move forward to riding/tuning.
