XS750 No spark

DonCamalot

New Member
Hello everyone! I'm having issues with my XS750 not wanting to ignite. At first there was burps and pops, but never any ignition.I had it at a shop while I was away and the man installed a new third ignition coil and points. Now, the third is the only one producing spark. I've changed coils, spark plugs, and ignition cable. It seems like the power is only getting sent to the third coil. Any advice or suggestions are greatly appreciated, thanks.
 
make sure you're getting a good clean snap at the points, then check the condensors. unplug coil 3 and swap it's plug to 1 and see if 1 gets spark, repeat for 2. this will help determine if all three coils are any good.
 
is it a point ignition or the later e-ignition?

Had the same issues.
It ultimately was a faulty ignition box (just had spark on cyl3 then swapped the box and suddenly had spark on all 3).

Swap around coils like focus suggested, then let us know the result!
 
I have swapped coils around, and they all work only on the third cylinder configuration. The hitches appear to be getting a solid snap... is there any way to check the condensers?
Unfortunately, I have mechanical timing. Trying to save up for a electronic conversion
 
Have you checked for power at all the coils?

Also, have you verified (with a test light or multimeter) that the points are opening and closing correctly?
 
I checked the mA on each terminal where the coils connect. The third piston gives me around 12-13mA while the other two give me .4 I don't know if that helps or what can be determined from it. The points where installed by someone who had a light. I honestly don't even know how to use one.
Thanks for all the help so far !!
 
Something's up. You shouldn't be able to get 25V without the engine running. And if you did have the engine running then you definitely have problems with the regulator.
 
I'll have to check what setting I had it in. Do you think the regulator is what's causing the firing on only one?
It was never static it kept bouncing around even when the engine was trying to start
 
DonCamalot said:
I'll have to check what setting I had it in. Do you think the regulator is what's causing the firing on only one?
It was never static it kept bouncing around even when the engine was trying to start

It's possible. But to check for sure, I would measure voltage across the battery terminals and not at the coils.
 
After reading this, has the bike been parked up for a long time? Let's try the easiest solution first: get some 800-1000 grit emery paper fold it, so you have two gritty sides, put it between the points of the cylinders not working and pull it through (when the contact is closed) - no pressure or anything.

If the points have glassed up, that'll break open the insulating layer and you should be good to go again. Next turn on the ignition and open one of the closed points, you should be able to see a tiny spark, if it's a big one the corresponding condenser has let go.

Hope this gives you something to start with
Greg
 
Okay, I've cleaned up the points. Swapped the condensers. And I'm getting a really solid blue spark. The only problem is, that's with my hand manually opening the point. As soon as the starter is engaged, the spark goes away. Any ideas? New points?
 
Time to break out the multimeter.

Turn everything off and measure resistance between the open side of each point and the closed side. When the point is open, you should get an Open Line reading. With the point closed, it should be very close to zero.
 
Sonreir™ said:
Time to break out the multimeter.

Turn everything off and measure resistance between the open side of each point and the closed side. When the point is open, you should get an Open Line reading. With the point closed, it should be very close to zero.

I'm getting a round a 6 on resistance across all three pistons. Open does go to OL.
 
That's a little high, but should still be workable.

Next step, turn everything on and measure voltage on the open side of each point (when it's open).
 
Sonreir™ said:
That's a little high, but should still be workable.

Next step, turn everything on and measure voltage on the open side of each point (when it's open).

Voltage is reading 10 from where the coil connects to. And open it slowly decreases to .003+_
Thanks again for you continues help!
 
Ok. You did a load test, or you just measured voltage? Not sure if it really matters, but never hurts :) And did you happen to install an aftermarket reg/rec?
 
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