115083d no spark

flywheel magnets test what is it ? Started by flatsman, November 5th, 2003 02:23 PM

I just found this post and was wondering if this could be my issue. He is basically saying he was getting no spark and was wondering about week magnets he did put on a new flywheel and problem solved. His is a 1996 115 hp and mine is an old 1970 115 hp 115083d everything on mine checks out ohm wise. running a magnet across sensor I get voltage out of sensor wires but while cranking engine over there is no voltage and when I use a 1.5 volt battery across pulse pack sensor wires I spark thru coil every time. Sensor gap is set to 0.020 and still no spark. Has anyone else heard of this I understand it's rare. One more question is if my anti-reverse spring could be grounding out while cranking? Can I remove it to confirm that is not the issue without damaging anything? Looks to me like I can I?m just not sure.

Thanks in advance for your help
Don

Re: 115083d no spark

I'm thinking the sensor gap should be .028", but could be mistaken. Weak magnets are almost unheard of, but I suppose anything is possible. How is your cranking speed? The anti-reverse spring should be rotated up against the plastic block when cranking or running. It only grounds out when / if it tries to run backwards. Otherwise it does nothing. It should run if the spring is missing, but it also would be possible for it to run backwards.

EDIT: Oops, hold on there. That year does not have magnets to operate the sensor. It has a non-magnetic notched rotor.

EDIT, EDIT: To expand, the sensor is the magnet, the notched rotor disrupts the magnetic lines of force about it.

Re: 115083d no spark

Thanks FR you are right on the .028 gap. The CDI troubleshooting I downloaded said to reset to .020 and try again. As for the sensor being the magnet I will pull the flywheel and see. However it sure looks like a pick up coil and when I used a small magnet across it I got voltage out which I assume triggers the pulse pack to send voltage to the coil and create the ?” spark. I could not move the magnet across the sensor fast enough to create a spark but using a AA battery and touching wires to battery I could make the pulse pack fire and spark jump the ?” gap.

Thanks
Don

Re: 115083d no spark

Well, as somebody once said, I know just enough about electronics to be dangerous. I had formal training on that ignition system when it was new, but I know there are better ways of doing it now. I say that because I don't know about the AA battery test. What I learned was with key on, and trigger wheel notch aligned with sensor, pass a feeler gage across the sensor. That should trigger the pulse pack and create a spark from the coil. Another test is to check the resistance of the sensor with an ohm meter. Should be 6-8 ohms. Should be no continuity between sensor wire and ground. Still another test is with key on, unplug and re-plug the sensor wire. Each time you unplug it, there should be a spark from the coil.

Really all that good knowledge aside, if the sensor ohms out ok, and is not shorted to ground, and the gap is anywhere near right, it should work. If it doesn't, the problem is not in the sensor circuit. Most likely the pulse pack is not energizing the sensor.

As I understand the system (?), the pulse pack sends a small voltage to the sensor, which magnetizes it. Then the trigger wheel breaks the magnetic field, which the pulse pack can detect. That discharges the internal storage capacitor through the coil, causing the spark.

Re: 115083d no spark

Sorry it took so long to get back to this (day job has to pay for the fun stuff)
FR first let me thank you for all your help.
Anyway that makes a lot more sense to me now. Voltage from the pack turns sensor into an electro magnet and the rotor passes thru the magnetic field increasing that voltage triggering the pack to send 200 volts to the coil. So I hooked everything back up and nothing so did some voltage checks. If the pack supplies voltage to the sensor to turn it into an electro magnet then I should have a voltage reading. I have none, so I’m assuming it is the pulse pack. Not being one to throw parts at stuff I did some more reading. The trigger rotor on mine is a phase 2 and the pack # is 398363. If mine is indeed a phase 2 system CDI says” Remove any clipper modules, surge suppressors or safety circuits. WARNING! Failure to do so could void CD warranty”. Mine still has the ign. safety circuit installed. Sounds like I Should remove the ign. safety circuit and check for voltage to the sensor. What are your thoughts?

Thanks
Don

Re: 115083d no spark

If CDI says remove it , give it a try.

Re: 115083d no spark

I don't know much about the CDI replacement pulse packs. But I can see that they may have incorporated the features of that other stuff in the new circuitry, which would make sense.

I can tell you that the original pulse packs could produce a spark when you turn the key on...before you run the starter. That could cause a spontaneous and unintended startup, possibly causing an accident. So, enter the safety switch. That switch prevents the 12V from the key switch from getting to the pulse pack before the starter is cranking the engine. In other words, simply turning the key on does not power up the pulse pack. The flywheel must be rotating before the pulse pack has any power input......or output. An output voltage from the rotating flywheel alternator is what turns the safety switch on.

So, that is what I know about it. I'm getting too old to keep up with the changes made since then.

Re: 115083d no spark

Yes I remember the safety switch and the starting with just turning the key on. But since those days they changed the packs so they wouldn't do that.

Re: 115083d no spark

FR you are still a wealth of knowledge so keep on keeping on.
I should elaborate on my pulse pack it very well could be the original not sure. It is an OMC 398363 made by Wabash I will try attaching a photo. The wire colors are purple, blue, white, black/white stripe, black/green stripe, and two ground wires. Blue wire goes to terminal 5 and purple wire goes to terminal 7 the white and black/white wires go to the sensor. When I wrote about CDI I meant that I downloaded their trouble shooting manual and read that statement, so probably not correct in removing the ignition Safety switch unless using their pack.
I guess I am not following you very well though. You and the manual both say the same thing, with the key switch on unplug and plug sensor wires and you should jump a spark ?” each time. Then you say there is no power going to the pack unless cranking engine over. So I’m just curious if there is no power going to the pulse pack until cranking, then how will just turning on the key, energize the sensor to create a spark. I am guessing that with the key on I should have a low voltage currant to energize the sensor and while unplugging wires simulate the trigger cutting through the magnetic field creating a spark. So maybe I’m just over thinking this. I believe I am going to buy a used pulse pack to see if I indeed have voltage going to sensor. If I do not have voltage then it must be something else and I have a spare pack.

sorry can not upload photo

Thanks
Don

Re: 115083d no spark

I guess it did attach just didn't show untill I posted now I know

Re: 115083d no spark

I am not familiar with the pulse pack that you have. The originals were made by Prestolite. Also, it appears the wires are non-standard.

OK, you are one step ahead of me because you have the manual and I don't. But you are correct in your thinking. Doesn't the manual tell you to bypass the safety switch by moving the pulse pack input (purple/black) wire over to the purple wires terminal before making the sensor test? If it doesn't, it should. That will turn the pack "on".

Re: 115083d no spark

FR:

Okay been awhile since last post, I was searching for and bought a used pulse pack. It came in Friday afternoon checked it out Saturday AM. Then I got called into work. That’s the price of saying yes to boss position LOL. Hooked 12 volts to purple and checked the white wire has 4.67 volts, whoopee, looks promising. I Plan on hooking up tomorrow. Good lord willing and the creek don’t rise!! Hopefully I get spark to the coil and then on to the plugs. Sorry it took so long to re-post. For those wondering like me you should get voltage from pulse pack to sensor wire. This should turn the sensor into an electro magnet and the trigger breaking the magnetic field should increase or decrease this voltage triggering the 200 volt pulse. Still am not sure if 4.67 volts is enough to create spark. I will let you know!

Re: 115083d no spark

Okay everyone best laid plans. Anyway I finally got back to this project. I hooked up pulse pack double checked everything sensor and wire connections. You guessed it good news bad news. I have great spark from coil but when hooked back to the distributor and checked plugs I have very week and sporadic spark. Now to double check wires and distributor.

Re: 115083d no spark

removed distributor and cleaned inside to get a good visual inspection. found carbon trail from coil brass to #1 cylinder brass. so now searching for distributor and probably rotor. if it wern't for bad luck I'd have no luck at all LOL

Re: 115083d no spark

I realy think a distributor is something I should not buy used. any opinions???

Did a new rotor and distributor fix the problem?

hopefully he did 8 years ago ....

Knotshore----Start your own post if you have one of these 1970 motors with issues.---Post all about your motor issues.