MicroSquirt.com read only forum (Jan.15,2018)

I have been doing a bunch of research on the feasibility of using the microsquirt as a replacement for my ignition on my motorcycle. Please review what I am planning and let me know if I am missing anything important.

My plan is to use the microsquirt module and the basica 2.5 bar MAP sensor. For the tach input I want to use the signal from the pulser coil in my stator. This is a potentially high voltage VR signal so it seems like right off the bat I should do the diode fix that I saw sticked in another subforum. Based on some other posts relating to VR sensors, I have a suspicion that due to the size of the pickup in relation to the reluctor the zero-crossing is going to be very wide (there will be a long delay between the positive pulse and the negative pulse). Is there a way to account for this in any of the available firmwares? So besides figuring out the offset angle of the reluctor that should be it right? I can just ignore all the fuel related settings?

Forgot to mention that I would be driving a D555 coil (wasted spark setup) so I know I need a BIP373.

What kind of bike is this? What tooth pattern does it use?

Spark is far less forgiving of tach drift than fuel.

This is an old 1982 Honda CM450. There are no "teeth" per se but I would assume it would operate like a single tooth wheel... there is 1 pickup coil and there is 1 reluctor on the flywheel rotor.

Hi Ryan,

CM450 aka SuperDream over here, parallel twin
Have you got a picture of the existing set up. I might be getting confused but isn't there a removal cam cover on top of the cylinder. I can't remember if an earlier version had a set of points in this.

Mike

Sounds like a single long tooth. I have an adaptor circuit that will turn that into a square-wave that can be read by the uS' VR or OPTO circuits.

Ryan - Back to your original post; yes, you can simply ignore the various fuel settings. Yes, you need to worry about a long tooth VR, but my circuit will take care of that. Don't worry about high VR voltages; any circuit designed to handle a VR signal will be capable of handling fairly significant AC voltage.

24c wrote:Hi Ryan,

CM450 aka SuperDream over here, parallel twin
Have you got a picture of the existing set up. I might be getting confused but isn't there a removal cam cover on top of the cylinder. I can't remember if an earlier version had a set of points in this.

Mike

There are no points anywhere on the bike. Here is a picture of the flywheel/rotor and the pickup coil.


The brass colored disc at the top of the rotor at the 11:45 position is the reluctor and the pickup is the thing at the 1:30-3 position.



Above is a diagram of the ignition system on this bike. All the diodes show above are inside of the CDI (which I am trying to replace).

dontz125, can you post a pic of the circuit schematic?

Hi Ryan,

OK, that brass thing is a single tooth then.
So in theory, if you took the plugs out and hooked up the VR sensor to an oscilloscope, you'd get a typical VR trace.
Is that brass thing or "PICKUP" magnetised or just a plain "zinc passivated" lump of steel?
Just out of curiosity are the holes (balance?) in the stator/flywheel on the same path as the brass thing?

Mike

I am out of town so can't confirm with a physical inspection until this weekend but from inspection of a few photos there appear to be at least 2 rows of balancing holes, one of which is closer to being inline with the reluctor tooth but does not appear to be directly in line with it. I also don't know if it is magnetic or not, I will check this weekend.

I am going to have access to a good oscilloscope this weekend. Besides the ignition signal is there any other signal that I should look at that might be relevant to the microsquirt?