Starter won't engage - R90/6

[hal]

Hi folks,

Been using my airhead way too little as my R850R is so nice and wellbehaving. It's gort breaks and all. Think that's my mainreason for not using the old /6 more. Maybe I should try to do something about it, like the big rotor thing from Matt..but $$££...

Anyway, tried to fire her up the other day to take her for a spin and the starter would not engage. Thought it might be battery, charged it and tried again some days later. Would not, then suddenly. Took her out but did not dare to stop. Tried again yesterday and all dead. Don't think it's battery-related. Bad connection someplace is more likelly. Think I will start at the grounding connections and then move on.
Anyone have a good idea to what this might be? Bike has been sitting still waay to much the last years. Will be some days before I have the time to start wrenching.

Thanks and all the best
Hal

[Kurt in S.A.]

Starter would not engage...what does that mean? Does the starter motor whir up and make noise or is the starter silent?

When you hit the starter button, what is the voltage reading across the battery terminals?

Kurt

[hal]

Thanks Kurt,

When I hit the starter button, nothing happens. haven't come down to faultfinding yet. Quite sure battery is OK, that's all. I do suspect bad connection someplace or maybe a relee?

[Kurt in S.A.]

Yeah, the starter relay under the tank is the first place to look.

Kurt

[Rob Frankham]

If nothing at all happens, and assuming that the 'idiot lights' show as normal, then the problem is more than likely around the supply via the ignition switch and the kill switch (if it's a late /6 which has one) , to the starter relay or from the starter relay to ground via the clutch switch or the dread diode on the circuit board and the Neutral switch... or it's the starter relay itself.

If you get a light click from the starter relay but nothing else, then the problem is between the starter relay and the starter solenoid.

If you get a loud clack then the problem is with the starter itself.

(If you don't get any 'idiot lights', then we're into a whole different ball game... but that's not how I read your post.

A couple of questions?

* Can you confirm that the bike won't start with the clutch pulled? If so, does the neutral lamp work properly? If it will start with the clutch pulled and the neutral lamp lights, than the problem is probably the diode mounted on the rear of the headlamp circuit board. If the neutral lamp doesn't light, it's the switch or the wiring to it.

* To assist, what is year of the bike? 74/75 bikes have different electrical wiring to '76 bikes.

Suggested tests...

1) Take off the starter cover, remove the small black spade connector from the rear of the solenoid and connect a length of wire in it's place. Briefly tap this wire to the battery positive. Does the starter run and engage...

• Yes - the starter is OK. Goto (2)
• No - The starter is bad

1a) Run a substantial temporary wire from battery positive to the big nut on the rear of the solenoid where the braid connects to the motor. Does the starter spin?

• Yes - The starter is good, the solenoid is bad.
• No - The starter is bad.

2) remove the tank and disconnect the wiring. Isolate the black wire. Briefly connect battery voltage to the black wire. Does the starter engage and run?

• Yes - The wiring from the relay to the solenoid is good. Goto (3)
• No - The wire from the relay to the solenoid is bad.

3) Still at the starter relay, check the red wires. If both are connected, both should be at battery voltage.

• a) If both are at battery voltage, the circuit is good. Goto (4)
• b) If one is at battery voltage but the other is at 0 volts or the voltage drops when the ignition is switched on, then the relay is defective.
• c) If the voltage on both drops substantially when the ignition is switched on, then the battery connection is bad or the wiring os defective
• d) If both are at 0 volts, then the red wire is broken (virtually impossible of you are getting any other circuits on the bike working).

4) Still at the relay, disconnect the Green/Black wire and use a voltage tester to check it when the ignition is on. Does it show battery voltage?

• Yes - The power to the relay is good. Goto (5)
• No - The wiring from the ignition switch to the relay is bad (Green/Black wiring) or the fuse is blown... a blown fuse is unlikely if you have all other circuits working.

5) Replace the green/black wire and remove the Brown/Yellow wire from the relay. Use a piece of wire to temporarily short the terminal (the one that the Brown/Yellow wire was on) on the relay to ground. Does the relay activate?

• Yes - The problem is with the grounding circuit for the relay, which goes either i) via the clutch switch (Brown/Yellow wire) or ii) via the headlamp circuit board diode and the neutral switch (Brown/Black Wire). Assuming the bike won't start with the clutch pulled or with the gearbox in neutral, the issue is likely to be between the relay and the circuit board.
• No - The relay is bad.

Hope that helps

Rob

[RPGR90s]

Its a matter of troubleshooting.
If you press the starter button, does the starter relay engage? (Click heard?)
If you press the starter button, are you getting 12vdc at the black starter solenoid wire? That's the signal from the starter relay that pulls in the LARGE solenoid inside the starter to spin it.

[hal]

Thanks Rob, this is a great list to start troubleshooting. Bike is a 74, produced late '73, so of the first /6. So no clutch switch, only the neutral switch. No clicks or any other sounds when hitting the starter button. It will be some days before I can get round to start troubleshooting, will get back with resoults.

Cheers guys!

[Airbear]

Thanks Rob, this is a great list to start troubleshooting. Bike is a 74, produced late '73, so of the first /6. So no clutch switch, only the neutral switch. No clicks or any other sounds when hitting the starter button. It will be some days before I can get round to start troubleshooting, will get back with resoults.

Cheers guys!

Hal, I have a September '73 90/6 with the /5 switchgear and it definitely came with a clutch switch. So there should be a diode on the back of your terminal board.

O, and please wish your bike a happy 50th birthday, er, when she wakes up.

[hal]

Thank you all for much appreciated help!

It turned out that the connections to the relay was falty/irrigated. some WD-40 sorted it all out. Got a chance to wrench a bit and faultseek it all on the way, much say it's a pleasure to work on this old machinery, Quality of it make it fell almost like new.

Cheers!

[Rob Frankham]

Thank you all for much appreciated help!

It turned out that the connections to the relay was falty/irrigated. some WD-40 sorted it all out. Got a chance to wrench a bit and faultseek it all on the way, much say it's a pleasure to work on this old machinery, Quality of it make it fell almost like new.

Cheers!

Thanks for the update... glad you found it.

Rob