What to check

[cajun31]

Attention electrical gurus....

I have an issue that I need to chase down. First off .... bike starts fine from cold start.... runs great. When I ride for about sixty or seventy miles and the bike gets warm.... or rather very warm here in the deep south and I stop for gas the bike sometimes will not start. When I push the starter button nothing. I have found that when this occurs I can shift the bike into gear, engage the clutch lever and then the bike cranks right up. So with these symptoms what is the problem? I don't want to unnecessarily buy the wrong parts. What do I need to check? One other question... where exactly is the neutral switch located?

[kboehringer]

where exactly is the neutral switch located?

About six inches in front of where your gear shifter is attached. It's on the underside of the motor but can be seen from the shifter side. Single Phillips screw holds the wire on it.

KURT

[3Phase]

Cajun,

Like an old Chevy that needs the starter thumped with a favorite rock or a hammer before it will run there are a few things you can check:

Bad Start solenoid
Loose battery cables
Loose starter mounting bolts
Loose 12V cable from the solenoid to the starter
Loose ground cable from the engine to the frame
Loose or worn starter brushes
Worn starter motor commutator


The wire to the Neutral switch is always 12V and the switch grounds it to turn on the light. That 12V should run the starter or not allow it to stop if it somehow got shorted into the Start circuit or it would blow the 10A Ignition fuse when the Start button is pressed with the transmission in Neutral.

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[cajun31]

Thanks for the replies

I have checked most of what you list. The puzzling thing is as I stated the bike starts and runs great. Something is getting hot after riding for a while and is when the problem begins. What on the bike has issues with getting hot? I will double check what you have listed again... however I am still open to other suggestions. As additional info... once the bike cools down it starts right up again.

[ViperRon]

Check the ground wires for corrosion. The same wires are used in the charging circuit and with headlight and running the bike if the ground wires are corroded they will tend to be less conductive when hot. There are also wires that go to the fuse block and have a habit of breaking near the crimp. Mainly the ignition fuse wires as I have had issues there before. However with your condition not starting in Neutral the connection or wire to the switch might be more suspect.

[3Phase]

Viper Ron's got a good list of things some more things to check, especially the fuse clips on the 10A Ignition fuse. I'd add the harness-to-handlebar wiring connector up by the frame steering head and the contacts inside the Kill switch.


The only part that gets hot is the starter motor because it's on the engine, the rest of the Start/Run circuit is just the fuse, one harness connector, the Kill switch and some wire that literally makes a circle:

Red/White wire from the 10A Ignition fuse ->

Kill Switch (this is why the starter won't work with the Kill switch open) ->

Ballast Resistor/Ignition Coils ->

TCI ->

Start Solenoid

From the solenoid, the Blue/White wire goes back up to the handlebars where the Start button grounds it and makes the solenoid work.

The next time it won't start, pull the right-hand side cover and jumper the Blue/White wire from the solenoid to ground and see if the starter motor kicks.

.

[Bonz]

My 80 SG doesn't have a neutral switch, it will start with clutch pulled in while in gear, sitting in neutral alone, or if I am not paying attention, fully in gear with the clutch out (silly me when that happens)...

Is the 80 LG a different beast in that it has a neutral switch? I mean, it sounds like it does have one based n what I am reading, so I am curious.

[3Phase]

Cajun, I have to ask: Are you absolutely sure that you have a 1980 XS1100LG?

The 1981 XS1100LH has a starter interlock system that involves the clutch, transmission and the sidestand. All of that happy horsehocky could have been bypassed but still intermittently mess with the Start circuit.

.

[Ranger_xs1100]

Lg

My 80 SG doesn't have a neutral switch, it will start with clutch pulled in while in gear, sitting in neutral alone, or if I am not paying attention, fully in gear with the clutch out (silly me when that happens)...

Is the 80 LG a different beast in that it has a neutral switch? I mean, it sounds like it does have one based n what I am reading, so I am curious.

Bonz, My LG's have the neutral switch as described, underneath and just ahead of the shifter with a single wire attached. However my LG's will also start while in gear and the clutch pulled in, or as you stated, the starter will turn even if you forget to pull the clutch in and lurch the bike forward! and sometimes causing it to fall over on it's side if you are not prepared for the surprise!

[mack]

If it won't start

in neutral but will if the tranny is engaged with the clutch pulled isn it has to be in the safety circuit. I know that on all my bikes that short lead from the harness to the switch is a very tight turn and all of them had cracks in the insulation. It is also right above the exhaust heat shield so it gets pretty hot. If it was me, I'd be looking at splicing into the harness and replacing that lead to the switch.

[3Phase]

In the '78 to '80 models the only thing the Neutral switch does is turn on the Green light for the neutral indicator and short out the pick-up coil wires in the
rain or after washing the bike.

'81 got the Start interlocks sort of grafted on.

The '82 XJ interlocks were more integrated and the number of optional short circuits for the pick-up coil wires was doubled with the addition of the Oil Level switch in the oil pan along with the Neutral switch.

.

[Bonz]

What confused me and I alluded to in my post is his signature says 80 LG. He must mean 81 LH.

[cajun31]

Again thanks for the replies

I am positive I own an 80LG. I bought it brand new and have owned it for 36 years. Recently restored it and it has been running great. This problem has just recently raised it's ugly head and I am jus trying to gather ideas as to what is going on. It has to be something that is failing due to heat. Doesn't make sense otherwise. Starts cold every time and only acts up after the bike gets hot after riding for a while. I had a problem last year with the misuse of dielectric grease. You can search my handle for that thread. Was quite an ordeal... however it did cause me to check and clean every ground and electrical connection on the bike. I stored the bike inside my garage covered. I am not saying that corrosion can't occur because I do live in the deep south (can you say humidity) an understatement here. I will double check all my connections. Mack I am not sure about the safety circuit ... because like I said it starts fine every time until the bike gets really hot. My worries at this point, obviously is getting stranded somewhere. Makes me not want to ride this bike as I have the alternative to ride my Harley. I am really looking for things to check... Keep throwing ideas at me... thanks.

[bikerphil]

The easy way to check for an interlock is to see if there is a set of two wires running directly to the clutch perch where there would be a clutch lever travel switch.

[3Phase]

Okay, it's an '80 LG. I believe you, honest, and there is no Start safety circuit!

What you have is a simple +12V Ignition circuit with a Start solenoid hanging off of it, there is no mystery component. If you believe in mystery components then you may as well polish your pirate suit, get a couple of dozen gremlin bells and go ride the Harley.

The next time your 'LG won't start, pull the right-hand side cover and measure the voltage at the solenoid Red/White wire and the Blue/White wire OR jumper the Blue/White wire from the Start solenoid to ground.

Don't ground the Red/White wire unless you just like changing Ignition fuses.

If the solenoid works then you have a bad handlebar ground or the harness-to-handlebar connector is bad. If it doesn't work or there is no voltage at the Red/White wire then the Ignition circuit is bad. Check the 10A Ignition fuse and the fuse clips. If they're hot and you suddenly have voltage at the solenoid again after jostling the fuse then replace the fuse block.

If there is no voltage at the Blue/White wire then the solenoid is bad.


Once again:

Check the +12V supply.

Check for a bad 10A Ignition fuse or the old fuse clips getting hot and losing the connection -- no +12V, no Start solenoid. There is a reason people add T.C.'s fuse block and it's not to keep up with the latest fashion trends in thermal current limit systems.

Bad Start solenoid. The one on my '80G had a broken wire inside that would usually make contact with the solder blob for the Red/White wire. It tested good every time until I took it apart and found and fixed the broken wire on the solenoid coil.

Bad starter brushes. When the brushes wear down they can't make a reliable connection with the commutator. When the starter motor is hot like from, say, 200 to 250 degree F oil bathing its nose while sitting on top of a hot transmission case then it takes a lot more current to make the motor work than when it's cold. Putting the transmission in gear could bounce/move the starter motor enough for the brushes to make contact with the commutator again.

Bad commutator. Same problem as the brushes but you have to replace the starter, not just the brushes.


Check the grounds:

Handlebar ground. The Start button won't do anything if the handlebar ground isn't good. There is a Black ground wire on the left-hand control for the Turn Signals and pulling in the clutch after putting the transmission in gear may be what 'fixes' the bad ground for the Start button on the right-hand control.

Harness grounds. The main harness grounds are on the frame next to the voltage Regulator/Rectifier.

Engine ground. Runs from one of the the Middle Drive bolts to the frame below the battery. Again, putting the

Loose starter bolts. If the starter is loose it may work when it's cold but when it's hot and needs more current it may need a 'bump' like from putting the transmission in gear to to temporarily 'fix' the bad contact.


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