11am: I’m having some trouble with RPM sensing on my MicroSquirt. Previously I thought that I had fixed the problem but it appears to be back. The bike is otherwise in good health. I would consider taking my RPM data directly from the ignition pulse triggers but the pulse generator plate (shown as #22 here although I haven’t been able to find a part number for it in the microfiche yet.) has an oddly configured set of teeth. There appears to be difference in the spacing and also the thickness of the ring. This page and this page in the shop manual show that the bike actually has dual triggers for spark. The second figure on the second page linked in the last sentence shows what I think indicates that the bike’s ignition control module determines when to fire a spark based upon the absence of material rather than actually counting teeth. I however don’t know if this is true or not. Unfortunately I don’t have a man on the inside at Mother Honda in Japan to tell me the secrets that I need to know.
1pm: It looks like I’ve solved the RPM sensing problem. I discovered that I had the wires reversed for the RPM sense circuit. There is a small note for Pins 30 and 31 here that indicates the OPTION + should be connected to the ground terminal on my bike and the OPTION – should go to a clean 12V source. This is a bit backwards compared to what I’d expect but it seems to work. Now I am reading 800-900 RPM pretty consistently when cranking at the starter.
2pm: LIFE! I just had the bike up and idling!!!
3pm: Tuning is starting in earnest now. I’m having some troubles with a few quirks in the TunerStudio software. Also it appears that the shorter I set the pulse for the injectors, the more fuel is actually delivered. Not sure what that’s about! Also I can’t get the air fuel ratio up high enough even at hot idle. At hot idle, it’s ranging around 10.3-10.5 when it should be more like 14.7-15.2. I can’t figure out what to adjust to lean out the mixture but without reducing the idle speed.
I am looking for help on the MicroSquirt forums now for some of my questions. Hopefully I’ll have more time tomorrow to work on this.