Type of trigger wheel for 1cyl 4 stroke moto

[Mr Alter Ego]

Hi!

sorry for my bad english.
i have cn250 (scooter) engine, and i like to transfer it to fuel injection with microsquirt EFI.

for now, spark generates with scooter standart coil, with inductivity sensor on generator body. it have as like "piece of magnet" in 0 point, that fly around inductive sensor ... that do signal for spark.
i think for the first time, i can use squirt only for injection of fuel.
what type of trigger i need to use for 1 cylinder 4 stroke engine? it rev no more that 7000 revs per minute.
and where the best install trigger? for the me -easy to install on cam. but if that, for the future i cant use for spark ... in this case.
if for first time i was install to the cam, how many tooth i need ?

i am dont understand this moment.
can microsquirt work with two triggers (for future) ? one on cam and second on crank?
thanks

[24c]

You can use a cam trigger, no problem, but for the same number of teeth, the cam goes at half speed, and so 12 cam teeth is equivalent to 6 at the crankshaft.

The more teeth you can use the better the "resolution", but you might be limited in the size you can use in your engine.

[Mr Alter Ego]

thanks. i dont understand, for why wheel has no one tooth ? for example
X X X X X X X X X X X X X X X X X X __ X X X X X X X X X X X X X X X X X XX X X X X X X X X X X X X X X X X X
why there is no one tooth? it is for EFI can understand where is 0 point?

thanks very much

[dontz125]

I'm not sure what you're asking. The trigger wheel has ONE tooth? The trigger wheel has one hole, instead of a tooth?

Are you asking how a 36-1 wheel works? In that case, yes - this tells the EFI controller where the 'zero' point is.

[Mr Alter Ego]

Are you asking how a 36-1 wheel works? In that case, yes - this tells the EFI controller where the 'zero' point is.

yes. i try to understand, for what absent one tooth.
in any configarations, for cam and for crank, wheel must be with zero point? for example 60-2,36-1,12-1 etc.

thanks

[dontz125]

No. You can run JUST a crank wheel with a missing tooth (36-1, 12-1, 60-2), or a cam wheel the same way. You CAN run a crank wheel with no missing teeth (36-0, 4-0, 12-0) so long as you have a single-tooth cam wheel.

When running a 36-0 (12-0, 4-0 ... ) wheel, the cam tooth MUST ALWAYS be between the same two teeth. If the cam tooth happens between crank tooth #7 and tooth #8, it ALWAYS has to be there. If there is enough looseness to allow the cam tooth to happen between #6 and #7, the ECU will declare a synchronising error.

For what you are doing, a simple 8-1 wheel on the crank would probable be easiest, and LOTS of accuracy.

[Mr Alter Ego]

thanks!!!!
am correct understand, i can use wheel with no missing teeth, there must be second wheel, that have missing tooth. there is no way to work, when both wheels or only one wheel (setup) is with no missing teeth ? efi cant understand where is 0 and system dont work ?

thanks!