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

toon2 wrote:I was just on the manufacturers web site and ran across an artical on adjusting the ignition coils. It looks like they use a magnet on the flywheel and some type of coil pack to distribute the spark. It also say's it's an electronic ignition. The only Pic. they had of it was on a PDF file.

Could this be used to somehow to trigger the MS??

The sensor used to sense a magnet on a flywheel is called a "hall effect" my suggestion above is to use a VR sensor, same end result different method.

You need to place a trigger point on the outer diameter of your flywheel, usually at something like 10 degrees before top dead center. And the pickup sees this trigger point, whether it be a bolt head and VR or a Magnet and a hall sensor, makes little difference, the signal is input into the Megasquirt Tach input, and this signal is processed by the Megasquirt to give you an ignition output that with a V3.0 board, or the addition of a coil driver you can drive an ignition coil on a 2 cylinder engine with a single coil in wasted spark mode.

I am looking for a fuel only trigger at this point. Are you talking about spark advance

Or does it matter? Either way I will need to install a VR sensor?

toon2 wrote:I am looking for a fuel only trigger at this point. Are you talking about spark advance

Or does it matter? Either way I will need to install a VR sensor?

Yes, I guess that i think that if you are going to do it, you should do it right the first time, but I would not blame you for starting out with fuel only.
For fuel only you just need a trigger from an ignition event, there are many ways to get this, you could tap right off the magneto and feed that directly into the Megasquirt opto input, though you may have to add some resistance based on the voltage spike you get from that signal. Also you could use a inductive pickup from a timing light to triger the Megasquirt, or just a few wraps of wire around the plug wire may work.....

I noticed the mini tach has a wire wrapped around one of the plug wires, I guess this is the same idea.

Where is the best source to get a VR sensor? I will go this route as I will eventually want spark advance.

Also, I was thinking it might be possible to mount a TPS to the lever arm that is attached to the twist gripp of the tiller handle rather than the carb. .
This will give me a true throttle posistion as opposed to the carb/TB.

The carb/TB butterflys are wide open with 1/4 turn of the twist grip and then everything after that is against the governor.

Well, since I'm a Ford guy the Ford sensors are the ones I would use, the type you need depends on how you need to mount it. Most of the Ford Crank mounted Vr sensors have a two bolt setup mounted on the side, the Zetec has a through hole mount with a single hole mount. You'll find VR sensors all over modern cars, most all ABS sensors are VR as well as the majority of Cam and Crank sensors.

You can mount your TPS any where as long as you get a consistant reading in relation to your butterfly opening, but reaqlly it's not that critical as long as it works the same all the time.

thank's for all the help Scott, sorry to beat you up with all the questions.

For the TPS, The location I am thinking of will only turn the TPS about a 1/4 of a turn.

Can I tell MS through MT that it's WOT

toon2 wrote:thank's for all the help Scott, sorry to beat you up with all the questions.

For the TPS, The location I am thinking of will only turn the TPS about a 1/4 of a turn.

Can I tell MS through MT that it's WOT

It makes no difference how far the TPS turns, all of your adjustments for TPS are based on actual ADC counts.

What you do in Megatune is go to Tools->Calibrate TPS and you can specify the open and closed values that a fetched directly from the Megasquirt ADC, you want to write down those minimum and maximum values, what that does is calibrates the Megatune guage for the bottom and top of the scale. Now most of the other stuff related to TPS, like the flood clear value will be around 90% of your maximum TPS value. Some other values you may need to calculate actual TPS voltage, which is TPSADC / 1024 * 5.0

Edit - damn it, I got stuck in the MS1 thinking again, MS2 or Microsquirt sends the actual high and low values to the 'squirt and most of the variables are in percent of full scale, so really it still doesn't matter how much your TPS moves, Megasquirt knows what the full scale value is.

I forgot that really the MS2 firmware handles the TPS different than MS1, percentage of TPS full scale versus actual counts, so some of the original info I posted does not apply..

here are some pics of the ignition system, need some help figuring out if or how to make this work with MS

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