4217 Single Cylinder Programmable Ignition.

[RedRight]

Hi,

I am about to install the “4217” Single Cylinder Programmable Ignition
on my two stroke 50cc moped.
I want to use a magnetic pickup and a home made steel rotor on the crankshaft to trigger the system.

Just so I got it right. When using a magnetic pickup: Should the area before
TDC (“the timing tab”) be a low signal for example 35 degrees and the rest
och the 325 degrees a high signal?

My idea was to make a metal cut out in the rotor to create a low signal
starting 45 degrees before TDC and ending 10 degrees before TDC.

Please look at this image and see if you think this will work:



Thanks in advance!

/Karl-Magnus. Sweden.

[msdpstech1]

Hello Magnus,
Although the mag inputs of the 4217 were not designed to accept this type of signal it should in theory still work. On a magnetic pick up the sensor only needs to see a change in signal to trigger, whether it be a high or low signal. Sorry I cannot give you a more definite answer to your question than this. If you do decide to try this you may have to swap the mag input wires if the reading on your software is giving you a number over what your tab or in your case the slot is in degrees. This number will be displayed on the software with the engine idling between 800 and 1200 rpm. Please let me know how this works for you if you decide to go this route. Thanks, Bret- MSD Powersports Tech

[RedRight]

So, do you recomend using a "Hall Effekt" instead?
In that case, Should the HI and LOW signals be inverted so
that the 35 degrees in my example are HI in stead of LOW?

I was thinking of using this "Honeywell 1GT101" Hall sensor.

[msdpstech1]

Hello Magnus,
If you would prefer triggering the 4217 with a Hall Effect trigger I would recommend our 4154 pickup. The 4217 was designed to be run in conjunction with this style pickup. The pickup you are referring to may work with a reluctor style flywheel provided it will sense a wider tab then what is pictured in the illustration ( it must have only one tab as well, any more than one and it will not work). We have not triggered the 4217 with this style pickup so again I cannot give you a definite yes or no answer to this particular question.....sorry. If you would like more information on how to set up the 4154 as a trigger source please let me know. Thanks again, Bret- MSD Powersports Tech.

[RedRight]

Hello Magnus,
On a magnetic pick up the sensor only needs to see a change in signal to trigger, whether it be a high or low signal.

Sorry for all my stupid questions but I just need to clarify.
So what you are saying is that a magnetic pickup only needs to see a change in the signal
and it does not matter if it’s a high or low signal?
How does it determine that is the actual “timing area” and what is the rest of the crank circle
if it doesn’t matter if it is high or low signal?
Does it automatically pick the shortest “part” of the signal and “guess” that that is the timing area?

If you should try doing that I am about to try with a magnetic pickup according to my illustration on top, what would you choose?:
A raise in the metal or a lowered cut out in the metal where I want the “timing area” to be?
And which of the two options could have a chance to work with a 3:rd party halleffekt sensor (What you can “raw hall”)?

Thanks in advance!

/Karl-Magnus. Sweden.

[msdpstech1]

Hello again Magnus,
The 4217 does only need to see a change in the signal whether it be "high" or "low". It is this change that the ignition will determine its timing capability. In the software supplied with the 4217 there is a section in the data editor called "pickup reference" this number (which represents your timing tab or in your case a cut out) needs to be programmed into the software and then saved to the ignition. This number can be measured with a degree wheel or with the engine running at idle (between 800 and 1200 RPM) a number will appear on the monitor screen as PkupWt. This number needs to be programmed into the ignition. The ignition will reference this number against the diameter of the flywheel and know that this is its timing capability. From our research we do know that a raised tab will work with a magnetic pickup but have never actually tried it the pickup you would like to use although I see no reason why it would not work. As for setting the software for what your trigger source would be I would have to say Raw Hall from the description you supplied. Please let me know if you have any other questions or if I did not answer any of your questions sufficiently. Thanks again, Bret-MSD Powersports Tech