Help with spark only setup for motorcycle

[24c]

Hi Ryan,

Obviously you want an idea what the VR is seeing, so an oscilloscope is a very useful tool.

For ignition control, IMO, it might be an idea to have a bit of vacuum sensing, if only to make the bike smoother when cruising etc less hesitant on part throttle, so you're looking at a MAP sensor. I wouldn't worry about this, first you need to know what the VR is doing, what shape signal you got got, how strong the signal is (peak to peak AC volts on cranking or kicking over), and that's about it. I reckon you could easily add a few teeth to that stator if needed as well, if you wanted to create a missing tooth wheel, but as it's just for ignition, I would look on the least amount of work being optimal.

Mike

[ryan.hope]

Thanks for the tips Mike. I have been planning on adding a MAP sensors. There is a port on the cylinder manifold near each carb that is meant to be used for syncing the carbs. I was planning on using these taps as my source of vacuum.

[24c]

Ryan,
Those tappings should work, but you might one to link them all together, and need to pinch the pipe or fit a restrictive hole before the MAP sensor.
You'll know if you get lots of oscillations when analysing the MAP signal, and you'll have a pretty good idea if you attached a vacuum gauge to one of the tappings too, and observe the fluctuations in the needle or levels.

Mike

[ryan.hope]

Yep, the idea is to join them with a T so that they balance out and have 1 tube feeding the map sensor. I know someone else who has done this with a with a programable ignition specifically made for this vintage of Honda. That unit however, after being shipped to the US from Poland is just as expensive as a microsquirt but not-opensource and not as featurefull which is why I would like to pioneer the MS route

[24c]

Hi again Ryan,
Poland, don't know that one...but IgniTech & Imfsoft both do stuff for bikes.
MicroSquirt isn't open source, but I get your drift.
Tunerstudio software is for me the biggest reason for using Megasquirt derived hardware, and then there's the development effort by others, and the add ons that really add to the pot.

Mike

[ryan.hope]

Yeah IgniTech is the company, guess I got the location wrong Regarding opensource, I mean to refer to the firmware.

[mfro]

The Ignitech - according to my knowledge - is better suited to the "single tooth" aproach than the Microsquirt.

It can be programmed for a "immediate fire"-mode where it triggers when it first sees the falling edge of the pickup.

On the contrary, the Microsquirt can only fire after it saw at least two low/high transitions, i.e. at the second revolution after start, earliest.

The single-tooth aproach will most likely work with the Microsquirt (I did my first attempts this way as well), but it won't be an easy start, probably. Forget about kickstarting.

The Microsquirt is much more versatile, on the other hand. I'd think about fitting a multi-teeth trigger wheel to your flywheel, if possible.