Ignition problems z750e -81

Hello!

Im posting this here to see if you can solve my mystery......

About 6 months ago i bought a z750e really cheap because i" did not run on all cylinders" (as it said in the advert). the guy who sold it had tried to get it fixed at some local motorbike repair-guy who had changed the pickup coils but he did not get it running and said it only runs on two cylinders.

When i got the bike home and tried starting it it did not run at all and "backfired" really bad in to the carbs.

i sat down and started redaing on the internet for solutions, after a while i came across a document that decribed the whole ignitionsystem and how it works.

This page said something about magnets behind the pickup coils and that you can put them the wrong way........hmmm

If you put ONE of them wrong the signal to the CDI will be weak.........
If you put both of them wrong the signal will be changed 180 degrees (+ and - will change).......hmmm.......maybe thats it!´(i thought)

Went out in the garage end swapped theese magnets (who were mounted correct accoring to the document) and the bike started !!

My question is, how can it be that way that i have to put the magnets wrong to get the bike running..........what else is wrong to cause this?

Can you give me any tips?

(excuse my strange writing, im from Sweden)

Your ignition has a 180 degree angle out of timing to the crank shaft and cam shaft timing.
You have to swap the picup coils or the electric connectors and not the magnet.
The so called repair guy do it wrong.

Ahh......i did not check the cables for the pickup-coils, i took for granted that he did it right....

Easy fix if that´s the only problem.....

Here some pictures for a better overview of the ignition system.



I am not sure about the 4-pin connector but i think you have to swap the picups to get your system as it should.

Michael

How did you check the magnet polarity? What was your reference magnet? Or did you use a meter?

The white stripes and dots from the factory are not consistent.

s3.amazonaws.com/gpzweb/Ignition/PickupA.../PickupAndRotor.html

loudhvx wrote: How did you check the magnet polarity? What was your reference magnet? Or did you use a meter?

The white stripes and dots from the factory are not consistent.

s3.amazonaws.com/gpzweb/Ignition/PickupA.../PickupAndRotor.html

I just swapped them around to see if anything happends.......and the bike started right away....

Scirocco wrote: Your ignition has a 180 degree angle out of timing to the crank shaft and cam shaft timing.
You have to swap the picup coils or the electric connectors and not the magnet.
The so called repair guy do it wrong.

Yesterday i checked the pickups and the cut/rejoined cables and it looks correct, the colors are the same as on the old pickups (got them in a box when i bought the bike) and it does not look like he mixed them up.
I checked the colurs all the way to the igniter and it looks good.

The bike runs quite okay as it is and have a mechanical timing advancer, should i care that i had to swap the magnets to get it running......or just drive it as it is...?

LaRzOn wrote: ...
The bike runs quite okay as it is and have a mechanical timing advancer, should i care that i had to swap the magnets to get it running......or just drive it as it is...?

The important thing is to get both magnets oriented with the same polarity, and get the signal polarity correct.
If it was wrong, symptoms would include incorrect timing, weak or erratic spark, backfiring, and the dwell would be wrong so the coils might run a little warmer.

If you are worried about it, the link shows how to check that. It takes about 10 minutes, and a volt meter.

Okay, i will try to check all things up, according to the link you posted.

Thanks....

LaRzOn wrote: . . . backfired" really bad in to the carbs. . . .

Another common cause of backfiring through carbs is insufficient clearance on intake valves.

Good Fortune!

Patton wrote:

LaRzOn wrote: . . . backfired" really bad in to the carbs. . . .

Another common cause of backfiring through carbs is insufficient clearance on intake valves.

Good Fortune!

That is already checked and the bike runs pretty good efter i swapped the magnets......