Tach Signal Dont have one

[two stroker]

Thanks dontz ,tommorow im gonna try what ewflyer said if i have it right, install diode option- to neg of coil, install 1k resistor to option+ and to a 12v source . it looks like on diagram he goes to +of coil but cdi puts out 200plus volts if im not mistaken, does this sound right. if it dosent work the hall sensors should be here in a couple days. THanks for the info.

[dontz125]

He corrected himself later in that thread; EWFlyer is running a TCI system, with +12v upstream of the coil and the coil driver transistors grounding out the negative side. Your coils have the CDI upstream, but are wired directly to ground. The diodes & resistor arrangement won't work, as there's nothing to build up a voltage to detect - firing or off, the effective voltage at the reading point is zero (or Vf of the diodes).

Like I said - coil -ve triggering of a CDI is tricky. Try wiring OPTO+ to the positive side of the coil, see if the 250v+ pulse will trigger. Wire OPTO- to GND.

[two stroker]

Dontz i can try that should i put anything in line from the coil, resistor or something ,wont the big voltage hurt anything. thanks again

[dontz125]

Hmmm ... I think a 200v zener (band to the coil) AND A 1K RESISTOR inline to the OPTO+ pin, followed by a 30v zener BRANCHING to ground. Someone a little more up on electronics needs to comment here ...


EDIT to correct the circuit, so as to not have uncontrolled current flow (briefly) through the Zeners.

[boostaddict]

might wanna look at this, they say it will work on CDI ignitions, and will give a 12v tach signal

http://www.msdignition.com/uploadedFile ... ctions.pdf

[two stroker]

Ok got my gear tooth hall sensor from diy auto and tired it on my long teeth off my fly wheel, still no signal, tried different setting and nothing. I have a 36-1 wheel getting laser cut should be here in a couple days, if i still cant get a signal, maybe i fried something . All i want is fuel so i just need a tach signal, This is a two cyl 800cc two stroke summit skidoo mountain sled which i turboed last year, it ran great whith carbs, but a bit of a pain to jet ,I run from 1500ft to 9000 ft and up to 15psi of boost , hope this 36-1 wheel works Hate to put carbs back on. Thanks Ps This is the 3.770 code , should i load a different code.

[Conceptz-X]

I am building a similar sled. 03 Polaris RMK Vertical Escape with a turbocharged 990cc twin. I originally piggybacked off the ignition pickup but it was a poor signal due to the long reluctor teeth. I installed a 36-1 wheel and DIY AutoTune threaded Hall (gear-tooth) Sensor, at 1.5mm air gap I did not really get a signal, at .5mm its not consistent but it runs, won't accelerate, shows sync errors, etc. I will be playing more with the gap tomorrow as its a 2 hour job to adjust it on my sled

here is my build thread on another forum: http://www.realhomemadeturbo.com/forum/ ... 837.0.html

here is product info and a datasheet on the hall (gear-tooth) sensor: http://www.hamlin.com/product-detail.cfm?productid=102


I have a MS v.2905 software package and using TunerStudio to tune it. The crank sensor wired with 5a fused +12v to the red wire / Ground, black wire, and Pin 31 OptoIN- on the same ground circuit / and the Blue Wire going to pin 30 OptoIN+ on my MicroSquirt

[Conceptz-X]

After spending most of the day on it, I haven't made any progress and managed to destroy a starter rope.
I'm going to cut all but 2 teeth off the wheel (180 degrees apart and ~10 degrees BTDC) so that I can run the signal as a basic trigger.
Not sure if I got a junk sensor or what. I do have a similar Omron sensor, but its rated for a lower frequency. I know it will work with just 2 teeth.

[two stroker]

I installed my 36-1 wheel and gear hall sensor from diy and about 1mm gap and instant tach signal, it works good. started to tune and the new turbo I installed blew a hole in the exhaust outlet, they installed bigger impeller and took to much meat off, should get new one friday and start tuning again. Does auto mixture control work as good as auto tune, can i set the seconds down to say 60 sec , then put it back up after. Thanks

[Conceptz-X]

What angle is the missing tooth at from TDC? I have tried it at ~30 and 90 degrees with no luck in either position. I believe I have an issue with the acceleration/deceleration of the crank making it difficult to determine the location of the missing tooth.