RPMs SOMETIMES read half...?

[ScramblerXLE]

Hey guys,

I'm trying to do fuel only on a single, fat tooth setup (I know) using the stock CDI system for ignition. The tooth is only about 28 mm long, so it's not crazy long. This is on a KTM 525 engine, and there are not a lot of attractive options for a trigger wheel, and to be 100% honest, I have an adjustable CDI with several maps and I can switch on the fly and I like that ability and would not want to give it up anyway, so I figured I'd try fuel only.

Since I have to leave the stock fat tooth in tact for that to continue working, I made an adapter that wired VR1 in line with the stock VR sensor, and lo and behold, I have a good tach signal! It starts up and idles and there doesn't appear to be any noise or anything from what I'm seeing. Microsquirt seems to track very nicely and never seems to lose the crank signal.

The problem I'm having is this: SOMETIMES, I start the engine and the tach values still track perfectly, but are reading precisely half of what they are really running. Then I can shut the engine off, start it back up, and it will read like normal. I've attached 2 log files, I made literally zero changes between them, just turned the engine off, let it sit for a couple of seconds, then turned it back on. As you can see, the second log file, the RPMs are correct.

Any ideas what could cause that? It doesn't seem like the longer-than-desired tooth would be the issue, as it never loses sync or behaves erratically at all. It was reading double until I changed it to 2 cylinders, so at least that's fixed now, but I'm not sure why it would read half sometimes...

Thanks in advance for any help!

[ScramblerXLE]

Some additional data that may help:

Here is my MSQ file. I have only been testing to see if I can get a tach signal to work, so lots of other things are probably quite messed up.

In addition, here is the log file from earlier when it was reading double. Interestingly, after looking at the log files, that's the only one that shows 'Yes' in the RUNNING box. Not sure why that would be...?

Thanks again!