1986 Maxim 750 x Electrical Problem. Please Help!

Hi all. I just purchased a 1986 Maxim x 750 last week. It had been in storage for a year or so according to previous owner. Bike was running o.k for a few days, some gas fumes in the oil ( Carb needs cleaning I suspect). Recently, I started the bike it ran for about 30 seconds and I think I heard a slight "pop". Everything died. No lights, no green neutral lamp indicator, nothing. Zero. Zilch. Nada.

I checked the battery - 12.54 volts.

Checked the selenoid - 1 side 12.54 volts, other side zero with key off.
1 side 12.54 volts, other side zero with key on.

Removed the ground wire and checked the selenoid again-
1 side 12.54 volts, other side zero with key off.
1 side 12.54 volts, OTHER SIDE 12.54 VOLTS KEY ON.

I replaced the ground wire- same deal.

A few hrs later, I turned the key and voila! All lights are on! Turn the key to start, hit he starter button and... Dead. Everything gone. Again. This has happened twice.

I really dont know what to next except clean all connections. Or perhaps the TCI is not reading enough voltage from the battery? A new battery?

Any input would be appreciated.

Thanks

Little John

 

You obviously have a multimeter, do you gave a manual for the bike? Learn to use both, small steps. There is a how-to on here by kmoe, I haven't looked through it but expect it would be a good place to start.

 

so you turn on key, ligts light and when you press starter button all lights shut down? starter does not spin?



first suggestion would be check the wire from battery positive to main fuse it will/should be a single wire with a connector to main harness red with sleaving on it.
make sure it is clean and connectors connectiong. check main fuse, test voltage
do a voltage drop test on battery when pressing starter button.


look at ignition switch. you should check connections there and also clean the switch. when you have switch off see if the key number is on the bottom of switch and write it down.
Clean and lube the ignition switch.

 

Thanks for your replies, I've checked the main fuse and cleaned the kill switch. Weird thing is when I turn the key on and disconnect the ground from the negative terminal of the battery, the solenoid reads 12.54 volts. However, when I connect the ground to the battery it reads ZERO with the ignition switch turned on. Is this normal?

I have no power at all. Headlight doesn't come on when I turn the key. Its like there isn't a battery in the bike. I'm wondering if a bad ground could be causing the problem. Can anyone confirm whether this could be the issue?

Thanks in advance. BTW I also own an 85 xj 700 Maxim and I had to clean all the connections for it to start reliably but I have never run into this situation.

 

check your battery markings make sure you have solinoid wire to positive motor ground to negitive.

 

O.k. Just spent a couple of hours cleaning connections to the coils, horn, solenoid (both sides), grounds, and other misc. connectors and got my lights and neutral light back. I pressed the start button and voltage dropped to less than 1 volt. It took a while but the battery came back up to 12.54. Tried it again and voltage dropped to almost zero again. I'm guessing it's the battery.

 

does sound like a bad battery

 

Replaced the battery, situation resolved.

 

Which battery should I use when it comes to V and Ah? I'm trying to use as little as possible because my XJ750 is under modifications to cafe racer... Any good idea to hide it as much as possible?

 

this thread may be of intrest
Slightly altered 83 XJ750 Maxim