Tach Signal Dont have one

[two stroker]

Boys i need help ,just finishished wiring tonite and cant get a tach signal. This is a 800cc two stroke fuel only , its a micro squirt v3.0 with ms11 v3.77000 , i have connection to the computer, tps works baros work, temp sensors work . I went off the neg of my coil, option+ to neg and option- to 12 volt. Is there some settings i have to do in tuner studio for it to work . Thanks in advance.

[dontz125]

You should be set to 'Basic Trigger'.

[two stroker]

Thanks dontz but there seems to be no basic trigger, in ignition set up theres lots of settings but nothing for triggering off coil or fuel only settings Thanks

[Bernard Fife]

2strokr,

The 'basic trigger' setting is NOT for B&G code, so ignore that advice. Instead, for a distributor you have to make sure the number of teeth is set to zero in the missing tooth setting under Advanced Ignition Options: http://www.megamanual.com/mt28.htm#ia As long as the teeth are set to zero, you should be okay.

However, if that still doesn't work, you might need to adjust the Time Mask, Percentage Mask, or Next Pulse Tolerances under 'Base Ignition Settings': http://www.megamanual.com/mt28.htm#ib

You might also want to post an MSQ and a datalog while cranking.

Lance.

[dontz125]

The 'basic trigger' setting is NOT for B&G code,

*sigh*

[two stroker]

Ok tried a few different things still no pulse, orderd a hall sensor just in case. my flywheel has two long teeth on it 180 from each other. will a hall work on this and can i use 12v or shoul i use vref for power. And what wire should the hall go to on my micro squirt v3.0 . ps is there a way i could rob a signal of my stock trigger( with out screwing up ignition), it has two triggers spaced 2" apart Thanks again.

[24c]

my flywheel has two long teeth on it 180 from each other. ... ps is there a way i could rob a signal of my stock trigger( with out screwing up ignition), it has two triggers spaced 2" apart

There is a possibility you could use your set up to trigger the ignition, but it all depends on the VR trace you have. Can you scope the signals coming off one of your sensors? If I understand your situation correctly, you can in theory add another sensor, and the two teeth at 180 degrees apart would create the Tach events you need for your fuelling, but it seems a long winded way to achieve this, when you have two sensors and a "trigger wheel" in place already.

Best option IMO, assuming the "long teeth" work OK, would be to strip out one VR sensor and use the remaining one for ignition and fuelling, but you have even more work to do to get it running then. Do you have any pictures of your triggering set up? Can it be easily modded? Is your ignition inductive or CDI?

[dontz125]

Long-tooth wheels and MS VR circuits don't play nice; I think James Murray tried every variant trying to get a uS or a MS to read properly. The problem is that the MS wants to identify the center of the tooth by registering the 'zero-crossing' of the signal, but the zero-crossing occurs unpredictably and unrepeatably with a long-tooth. The bike OEMs are looking for the leading and trailing edges, not the center, so they don't have the same issue.

What is the angle between the sensors? The teeth are at 180deg, but what is the angle of the pick-ups?

You need a Gear-tooth sensor, not a Hall sensor. The GTS is a Hall sensor with a magnet glued behind it in the sensor body; the tooth 'pulls' the magnet's field, triggering the sensor. Whether you need 5 or 12v depends on the particular sensor. GTS / Hall sensors usually have 3 wires - +V, Ground, and Signal.

The question as to whether the stock ignition is CDI or TCI (inductive) is fairly important; coil -ve with CDI is tricky due to the high voltages, and the uS can't directly fire CDI.

[two stroker]

Thanks for the info, yes the ign is cdi . I was just reading inthe manual under distributers , and it says hall sensors can be used on ringgear teeth, is that possible ,i have electric start the ring gear is about a foot across with around 90 teeth ,will that work on a hall sensor with no missing teeth, dont really want to grind any out ha ha . it says to to connect the signal wire to pin 24 on the ms what pin is that on my microsquirt thanks

[dontz125]

A 90-0 crank wheel will work, but (Lance or kjones may need to correct me) you'll need SOMETHING to indicate where #1 TDC is. Instead of removing a tooth, perhaps you could ADD something, or find something or somewhere that a 'lump' goes past that a second sensor could detect. A few of the bike guys have used gear sensors to pick up a valve lobe going past to indicate phase with a missing tooth crank wheel; obviously not a direct comparison, but it should indicate the kind of thing to look for.

Perhaps something as simple as adding a spacer or bolt head to that starter gear, something that stands proud and can be picked up by a second sensor.