An electro gremlin ate my spark.

Hi all,

I haven't been on in awhile but I kindly appreciate all of the advice that I've been given by the users of this website. Now I ask for your help in killing an electro gremlin that has taken up residence in an otherwise perfect XJ750 Maxim. I don't know much about electronics but I have every part imaginable to swap out.

Here's what I know,
- The starter works great. The battery is brand new.
- It won't start because there's no spark.
- The PO was able to start it last year but he said the bike did not run well.
- At one point it was driven without a battery for about 10 km.
- It was started multiple times from a battery charger. So many times, in fact that a perfectly good battery was ruined and had to be replaced.

I have lots of parts so I started by replacing the ignitor.
- Before I replaced the ignitor there was no spark at all.
- After I replaced the ignitor it still didn't get spark.
- It did, however, spark once if I left it sit for about five minutes and turned it on and off with the key. The spark came when I turned the key, not when I pushed the starter button.
- It has an aftermarket Audi horn.
- The starter circuit cutoff relay appears to be after market. It clicks. I replaced it with the stock part. It still clicks. I switched it back to the after market.
- I tried hooking up a different rectifier and no change.

My next step was going to be to replace the ignition coils but I thought I'd better ask the experts first before I wasted my time chasing down this gremlin. I literally have every electronic part from the exact same model of bike. What should I do next?

Thank you for your time,

Aaron

 

Before you waste more time and money replacing good parts, have you replaced the fuse box? The ignition will not work without a reliable power source.
Is the side stand saftey circuit working and NOT dissabling the ignition?
Those are the first places to start trouble shooting .
You need to get a multi-meter and learn to use it to trouble shoot those components before they are replaced.

 

Hi Mlew,

Thanks for the feedback. Just so you're aware, there's $0 invested. All of the electronics are coming off a parts bike I have disassembled and stored. It had a cracked frame.

When I remove and replace the fuse marked 'ignition' the starter relay clicks on and off. The same is true of the main fuse. Does that mean that the fuse box is OK? Can we eliminate the fuse box as the problem?

I will check the side stand safety circuit but I was troubleshooting the electronics on the centre stand with the kick stand up. Also, the starter turns over when I push the starter button. When I hold the attached spark plug up to the engine block there is no spark. (Except for when I turn the key on and off, which is weird.)

Best,

Aaron.

 

To clarify, when I turn the key on the #1 spark plug sparks once after a period of sitting for about five minutes. It will not spark again after that.

 

Open the Headlight Bucket.

Look for any "Strange-looking" -or- Unusual wiring or splices.
Test the Ignition Switch
Test the Kill Switch

Be sure you used the right type of Relay for the one you replaced.

Since you hooked-up a Battery Charger and fried a Battery, ...
Unplug the Voltage Regulator.
Closely examine the Quick-connect Plugs.

Look for signs of overheating, melting or Wires pulled-out from the socket.