Electrical puzzle

So I have decided to give this puzzle it's own thread and hopefully help somebody in the future with similar issues.

My 1982 XJ750 Maxim decided to give me a hard time to start one day, I checked for spark with brand new spark plugs, and 1 and 4 had no spark until I let the start button go and it would give me ONE spark. 2 and 3 had solid spark, no problems there.

I decided to go through the process of elimination and move down the lines. The first step was to cut 1/4 inch of the coils to make sure they had a good bite on the plug caps with no success. After that I swapped the coil with a spare one and tested again for spark... no luck.

This entire time I have been testing with my bike jumped to my car battery while the car is running to make sure that there is plenty of juice.

The next step was to swap the starter solenoid, no change.

After that the next step going down the line was to swap the TCI box which I did with no change.

Before all these I thought that the problem were the carbs and I took them off and got a good cleaning.

Thanks to Hogfiddles, he has been walking me through some of steps to test one thing after the other.

The next step will be to swap the diode behind the head light to make sure the problem is not there. Dave also mentioned to check the stator so I will have to learn how to do that and go over it.

Thank you to Dave and Master Shifu for the technical and emotional support during this adventure. I don't even like the maxim but here I am trying to get it to run so I can get rid of it and work on the seca

 

Get a fully charged battery in there and lose the jumper cables.

The firing when the button is released IS YOUR CLUE. It won't fire more than once, because it won't fire if the motor isn't turning.

SOMETHING is "eating" all available current when the starter is engaged, not allowing the ignition to fire.

You're making rash assumptions about your power source or the level thereof. The car could simply, by design, not be putting out the proper voltage for it to work. Or your starter sucks amps, to be quite blunt.

But something is eating the current or there isn't enough of it; and then when you let the button go, the ignition wakes up but then the motor stops turning.

 

Thanks Fitz,

It shouldn't be too hard to get another battery and slow charge it to get it in the bike. That is not a problem. Since I swapped the coil that seemed faulty, the starter solenoid and the TCI box. What else do you think could be the culprit? Should I swap starter motors and give it a try?

The other thing that I can think of is to get a new fuse box (it has the stock one) to make sure that enough juice travels properly through it.

I am just trying to figure out if there is something that I am missing or where else to look for faulty parts

 

We went round with the battery several times, and as much as I'd still like to say it's simply the battery, I've actually ruled that out. Simply, because with a strong car battery hooked up, there's got to be plenty of cranking amps now.

I recall at one point I suggested putting another battery in, and I thought he had........

Yeah, the spark right at the end still points to battery, but we've gone around on that enough times, heavy charging, ,etc....... still no change.

I've been through that kind of thing enough, but hooking up to a car or car battery has ALWAYS given a powerful turnover and quick start. It's not happening for Eco. So.......... time to check with the rest of the gurus.

dave F

 

Disconnect the Battery.
Pull the Starter.
Undo the two long Bolts after MARKING the line-up of the three sections.
(Electrical end ... Motor section ... Planet Drive.)

The Electrical-end often gets fouled with Carbon Dust causing the Starter to:
• Not spin
• Hesitate before cranking with difficulty
• Act like the Battery is dead.

Douche the Electrical-end, ... Commutator, Brushes and Housing.
Rubbing alcohol.
Straight out of the Bottle. Remove Cap. Puncture seal with toothpick.
Spray everything until what drips-out and off is as clean as what you are squirting in.

 

unplug the brain to the safety mechanisms. its under the gastank ull find it. 1 plug eliminates A LOT of wiring, work, headache and shorts. just dont start it in gear up on the kickstand without using the clutch hehe

 

park on hill so u dont have to run the bike to bumping speed

 

flip flop your plugs around, see if the problem follows

 

This sounds to me like you are loosing power through corroded wiring connections, and carbon dust build up in the starter.

Have you cleaned, and serviced the ignition switch, and starter yet?


Ghost