Won’t Start 1983 Yamaha XJ750 Maxim

Hey fellas!
New to the forms here just bought an 83 Yamaha XJ750 Maxim that wasn’t running. He said he had the carbs replaced rode for a few days and then the bike stopped running. Naturally I did some check overs with a friend who is a mechanic and we figured it to be the solenoid. Now I replaced the solenoid and it still won’t turn on. When I put the key in ignition all lights come on and everything. When I press the starter, the headlight, gauge lights, and I believe the taillight go out until I release but no click from solenoid or anything. I hope you guys could help me diagnose what else could be the problem! Thanks!

 

The lights going off is according to design. It's to save power for the starter. If the voltage is below the required amount, the bike won't start. I'd check the battery as a first step. I can't remember what amount the starter needs, but if you post your results, someone will be able to tell you.

 

Check the start button it may be the problem. Common for it to corrode and not contact. There is a tiny hole in the switch cluster under the button for spraying contact cleaner and lube. Or one of the cutout relays won't let you start it, side stand or clutch switch may be stuck.

 

Hey guys thanks for the response, battery voltage and the switch are both fine I forgot to mention that up above before checking the solenoid we check to make sure the battery was good and everything is fine. Checked clutch switch and side stand, all good. Still nothing turning on. Any other ideas of what the problem may be?

 

I don't think that bike has anything that would shut the lights off when starting. Sound to me like you have a bad connection somewhere, check the fusebox connections first. A corroded connection will pass electricity for a small load but once you put a big load on it it fails.

Have you jumped the large terminals on the solenoid to see if the motor will spin? Just because battery volts are good does not mean battery is good.

 

Starter relay

1. Inspection

a. Disconnect starter relay leads at the relay.

b. Connect pocket tester leads to the relay terminals (ohms x 1 scale).

c. Turn ignition to "ON" position, engine stop switch to "RUN" and change lever to "NEUTRAL".

d. Push the starter switch. The relay should click once and the scale should read zero if it does not read zero, the relay must be replaced.



1 Battery lead (+) 2. Starter motor lead

e. If the relay does not click, check the leads from the starter switch and from the battery (white/red, blue/white). Turn the ignition off. Use (ohms x 1) scale on tester. The resistance between these leads should be no more than 3.4 ohms. If there is more resistance, the relay should be replaced.



1 Blue/White 2 White/Red

Starting-circuit cut-off relay

1. Inspection

a. Remove the seat.

b. Remove the starting-circuit cut-off relay from the electrical components holding plate, and disconnect the connector.



1 Starting-circuit cut-off relay

c. Check the resistance of the relay coil windings with the pocket tester. If the resistance is not within specification, replace the relay.



d. Check the relay function with a 12 volt battery and the pocket tester. Connect the leads as shown in the illustration. If the resistance readings do not equal those shown in the illustration, replace the relay.



Neutral switch

Diode

1. Inspection

a. Remove the seat.

b. Remove the diode from the electrical components holding plate, and disconnect the connector.

c. Check the resistance of the diode with the pocket poster as shown in the illustration. If the resistance is not specification, replace the diode.

NOTE: Only the Yamaha Pocket Tester will give a 9.5 Ωreading when testing continuity. The particular characteristics of other testers will vary the continuity test readings.



1. Inspection

a. Remove the seat.

b. Disconnect the 4-pin connector from the main wire harness.

c. Connect the pocket tester leads as shown, and set the tester selector to ohm x 1.

When the transmission is in neutral, the tester should read zero ohms. When the transmission is in gear, the tester should read infinity.



1. Neutral 2 In gear 3. Sky blue 4 Ground

Clutch switch

1. Inspection

a. Remove the seat.

b. Disconnect the 4-pin connector from the main wire harness.

c. Connect the pocket tester leads as shown, and set the tester slector to ohm x 1.

When the clutch is disengaged, the tester should read zero ohms. When the clutch is engaged, the tester should read infinity.



1. Disengaged 2. Engaged 3. Black/Yellow 4. Ground

 

Ok sweet I plan to try these as soon as I get home, would you have any other suggestions in case all of these prove ok?

 

That's pretty much the whole deal there. If all that is okay I would suspect battery or loose/corroded connection somewhere. The above does not detail testing the actual starter switch itself but you've said that it is good. How did you test that? Will the starter spin if you jump the two large terminals on the solenoid?

 

Yup the starter spins if I jump the solenoid, tonight I'm going to try a full jump see if it works to test the battery fully. Updates later!

 

the contact for the headlight is part of the starter button and when pushed the headlight goes out.
dissassemble the control and clean the contacts of the starter button make sure the ground wire is grounded for the starter switch

 

Good to know, I found a wiring diagram and you are correct. Thanks for the info, beneficial to me and the OP.

 

Well here's a little update, so I tried to jump start the bike last night but nothing happened..I was trying to see if I was getting any spark from the plug but got nothing in return! Could this further more be the issue? Also when trying to put my multi meter on the starter plug that the plug from the starter solenoid connects to under the seat, no reading..Going to try to order the EXACT solenoid and not a universal one to see if that helps. Any other advice?

 

you want to chase the voltage fron ignition fuse to run/kill switch then down to tci and solinoid . could be the run switch needs to be cleaned .
red/white wire . do you have a manual or wiring diagram.
you also need to ohm out the ignition system. that whould be the ignition coils primary and secondary with and without the spark plug caps they unscrew. then the plug caps themselves. next is the pickup coils which is done from the connector at the tci. this will eliminate them as the no spark problem


XJ750 air-cooled models:

Pick-up coils:
650 ohms +/- 20% = 520 ohms to 780 ohms acceptable range


Ignition Coils:

Primary side (input from main wiring harness):
2.5 ohms +/- 10% = 2.25 ohms - 2.75 ohms acceptable range

Secondary side (spark plug wires, without their end caps):
11K ohms +/- 20% = 8,800 ohms - 13,200 ohms acceptable range


Spark plug caps:
1981-83 models: 5K +/- 20% = 4,000 to 6,000 ohms per cap acceptable range
1984 RL models: 10K +/- 20% = 8,000 to 12,000 ohms per cap acceptable range

Spark plugs:
0 ohms per plug

 

it is called Starter Relay Assy in parts book 50.31$ at dealership or any online oem supplier . numbers listed are old number and new number

Starter Relay Assy

3AY-81940-00-00
4KD-81940-00-00

our supporting vendor sells them too as well as any other parts you will need a couple of bucks extra but he will get you the correct parts. www.xj4ever.com or click his logo at top of page

do you still have glass fuses? could be the problem

HCP1680R Aftermarket starter Relay - SOLENOID, fits all XJ550, 1984-85 FJ600, 1986-88 YX600 Radian XJ650, 1981-84 XJ750, all XJ900RK, RL, N/FN, and F models, and XJ1100 models. NOTE: this relay is slightly smaller in the diameter of the can (about 1/4" smaller), and it is also about 2" shorter, end-to-end; however, it will fit into the original rubber insulator/holder and will perform as original. Correct colored lead wires off the solenoid have the correct white plastic 2-space wiring harness connector. Includes the rubber mounting grommet: Each: