Bike Won't Start 81SH

[mack]

Sup

I think you my need to rehang your wiring harness. If you have the factory service supplement, it shows and labels everything. If you don't I can take a picture of it and post it for you. I'll pull my sg harness off the wall and lay it out tomorrow and take a video of what everything is.

[Sup3rman86]

What is the placement of the vacuum lines in front of the carbs to the manifold boots?

[TopCatGr58]

Not sure what you're asking? The intake boots have synch ports that can also be used as vacuum ports. The Octy uses one to control it's valve. IF it's a standard, then the petcocks can go to the #1 and 4 ports to control them. The #2 carb has a port that is ONLY for the vacuum advance hose/pot that is under the timing cover.

T.C.

[Sup3rman86]

That was helpful, thank you. Also, are you going to take pics of the connections for my previous questions? I have to see the connections for it to make sense

[mack]

Poop

I got into some issues of my own and forgot, so do you want me to lay out the wiring harness and video everything and I can take a couple pictures of the supplement with the harness placement on/in the frame? Or are you just interested in the carb plumbing thing right now?

[Sup3rman86]

More so just interested in the front connections for the turn signals, the rear turn signals and the rear brake light connections

[Sup3rman86]

I am not getting any spark to my spark plugs, they are brand new so it has to be the ignition coils, but before I took the bike apart they were good, so how do I test them to make sure they are still good

[bikerphil]

Your battery may be too weak to fire the TCI, if the voltage dips below 10.5V during cranking, you may not have spark.

[Sup3rman86]

It's a brand new Shorai battery

[TopCatGr58]

I am not getting any spark to my spark plugs, they are brand new so it has to be the ignition coils, but before I took the bike apart they were good, so how do I test them to make sure they are still good

Hey there,

You say you are NOT getting spark to the plugs, how do you know??
To check for spark you still have to have the OTHER spark plug/wire connected, and the one you're testing has to be held against the engine/head, because the spark has to travel from the coil, thru the wire, plug, ENGINE, then back thru the other plug/wire back to the coil to complete the circuit for these paired coils. If you are just holding the plug away from the engine and cranking the engine, you will NOT see a spark.

To test the coils, you use an Ohmeter first on the Primary wires checking for proper amount of ohms....my 81 metered only ~2.5 ohms yet they still worked. The secondary wires/plug wires also checked WITHOUT the caps, should be about 15K ohms+/-10%.

T.C.

[Sup3rman86]

I did, I took the spark plug out, put I back in the coil wire and grounded it against the engine head and pushed the start button and the starter motor was going, but there was no spark in the plug...thoughts? I have a meter coming, I just ordered it, so I will check and update

[motoman]

I am not getting any spark to my spark plugs, they are brand new so it has to be the ignition coils, but before I took the bike apart they were good, so how do I test them to make sure they are still good

Possible, but not necessarily the case. The handle bar stop/run switch completes the ignition circuit. The plug-in for that switch, which runs top right side of frame would be a good easy place to start checking' key on' voltage. If that check shows the culprit, remove, take apart switch and clean contacts and connections. Careful of the teeny spring inside switch, that it doesen't boing off into nowhere.

[Sup3rman86]

So is the circuit not complete if I don't have the green/yellow and brown wires hooked up? Cause I have the other wires from the switch (2x red/white and a blue/white and black wire) hooked up

[Sup3rman86]

Does anyone have and are willing to send me a spare TDI igniter unit? I suspect that may be the reason my bike won't get spark...otherwise can you tell me what the specs are I should be getting from my multimeter while testing it. My coils test good so it has to be he igniter box, I just want to be 100% sure

[3Phase]

Sup,

The TCI (Transistor Controlled Ignition) for your '81 XS11 is a one-year-only box. 1981 4RO TCI boxes can be expensive and they're getting rare so you should check the power for the Ignition circuit and the TCI before you think about replacing it.

When you do find another 4RO TCI, keep in mind that if there is a wiring problem then doing a 'shotgun' test by swapping the boxes can ruin a perfectly good TCI and you'll have two dead boxes and some drywall to patch in the garage after you retrieve your meter and the new bad TCI.


So, on to the Ignition power!

If the Start solenoid works and the engine turns over when you press the Start button then your Ignition circuit is working and there is power to the TCI but there may not be enough power while you're cranking the engine.

The TCI starts to cut out and otherwise not work when the voltage drops below 10.(mumble) volts, like when you crank the engine.

Remove the right-hand side cover
Put your multimeter on DC Volts
Turn on the Ignition switch
Check the voltage from the Red/White wire on the Start solenoid to ground
The Red/White wire should have +12V, preferably closer to +12.5V or 12.7V
Press the Start button
The voltage at the Red/White wire should stay above +11V while cranking


It's a little late in the thread but here's a schematic layout for your Brake switch connections. The front Brake switch uses one side of the Brown 2-pole female spade connector, the Green/Yellow wire goes to the brake light:-