Bike Won't Start 81SH

[Sup3rman86]

I bought my 81 yamaha xs1100 a year and a half ago and the goof that I am, I had to take the bike apart (Minus the engine) so I knew how it all worked. I have it all back together and there are still few wires I don't know where they go. the starter works but the bike won't fire? I don't know what else to do, has new spark plugs, fresh battery, full tank, etc. does anyone know what I need to do?

[Dbshea]

I bought my 81 yamaha xs1100 a year and a half ago and the goof that I am, I had to take the bike apart (Minus the engine) so I knew how it all worked. I have it all back together and there are still few wires I don't know where they go. the starter works but the bike won't fire? I don't know what else to do, has new spark plugs, fresh battery, full tank, etc. does anyone know what I need to do?

Start a fresh thread with as much information as you can. What the symptoms are, what you did prior to the issue, etc. it'll get sorted out quickly on this forum, a lot of smart cats hang out here.

[TopCatGr58]

Hey there Sup3rman,

I moved your post and the reply to a new thread for you!

Did you download the service and owner's manuals in the links I provided to you when I notified you of your registration!? There's a wring diagram in them. There's also wiring diagrams in the tech tips, color so are easier to follow.

PHotos can help us help you, tell us where you have these loose wires, what are their colors, etc.. The 81SH has a separate MAIN FUSE on the left side of the bike/frame separate from the other fuses. Have you replaced the GLASS fuses and flimsy brass holders with new ATCO style solid fuses!?!? If not, that could be a source of no start.

The 81 is less likely to have the pickup coil wires break, less activity/rotation of the timing plate vs. the earlier models since they only move with the vacuum advance, the earlier models moved with the centrifugal mechanical advance and vac. adv.

T.C.

[Sup3rman86]

I did, thank you. Also, I have that original service manual and the clymer manual. They are helpful but I just can't see exactly what is supposed to go where as far as a couple wires go. I will take some pictures and pose them tomorrow. One is the black male end wire coming from the starter on the back of the engine, the red/black oil pressure switch wire, I have no clue where the oil pressure switch is and what wires hook up to the two rear brake switch. Like I said, I will post pics tomorrow. This is my first build so I'm short on experience, very eager to learn

[Sup3rman86]

https://mail.google.com/mail/u/0/?ui...0&disp=safe&zw

this is the image of the 3 wires I have hanging out of the front that I have no idea what to hook them up to

https://mail.google.com/mail/u/0/?ui...2&disp=safe&zw

https://mail.google.com/mail/u/0/?ui...&sz=w1240-h606

https://mail.google.com/mail/u/0/?ui...6&disp=safe&zw

these are the two wires at the back of the bike that might be one of the tail light wires.

https://mail.google.com/mail/u/0/?ui...8&disp=safe&zw

[TopCatGr58]

Hey there,

Not everybody has a Gmail account, so we can't see your photos!

You should get a photo hosting site account like www.photobucket.com to put your photos in, they permit direct linking of photos in forums and such!

T.C.

[Sup3rman86]

these are hanging out of the front

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http://s1174.photobucket.com/user/co...tml?sort=3&o=1

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http://i1174.photobucket.com/albums/...ps2g0ocvth.jpg

*

these are in the back of the bike

http://s1174.photobucket.com/user/co...tml?sort=3&o=3

*

http://s1174.photobucket.com/user/co...tml?sort=3&o=4

*[

any help or pictures of connected wiring any of you could offer would be greatly appreciated!

[wingnut]

The green and yellow are from the front brake switch and there is a mate for it in the harness.

[Sup3rman86]

Thank you for that. Does anyone know what the other wires are for?!

[TopCatGr58]

Hey there,

Okay, for the rear brake switch, the brown and the green/yellow on the harness side look like they go there according the wiring diagram. Note one is male, one female, both on the rear switch wires as well as the harness wires, only goes one way.

The Front wires....the solid red I think is a direct 12V+ hot unswitched wire for an accessory of your choice....test it with a voltmeter with the key off to see for sure. The big brown is a SWITCHED 12V+ source, again for an accessory if desired.

The rear harness, Blue is running lights/tail lights, and the black is probably ground, again test with voltmeter.

The other 3 wires on the rear, black, green, brown look like the ground and left/right turn signals wires.

I fixed your photo links to show the photos in the post instead of just being URL links!

T.C.

[Sup3rman86]

I appreciate it, I tore my bike down to the frame and left it like that for over a year cause other stuff got in the way, as far as the front and rear brake wire harnesses can you upload a picture so I can see what they look like? Also I have a two wire harness that is black and black / white out the front with one green end that is connected and the other end has a butt on it. Do you know where that goes? Again, pictures would be a huge help

[TopCatGr58]

Okay, the black and black/white wires are for the Emergency Stop/Run switch, according to the wiring diagram.

As to the brake switch harness photos...you have them for the rear, first is the actual switch, the second is of the harness wires that should plug into it.





The Front brake has a switch/wire that is part of the front caliper, you will need to trace it down from the handlebar into the headlight bucket and harness area.

T.C.

[mack]

Sup

Ok, here you go. The harness hanging on the wall is an SG but is basically the same.
https://youtu.be/E6IPhvQ66VY

https://youtu.be/4Fw70u2xFlc

https://youtu.be/DSnQX59RtdU

The bad news is I don't see anything with these wiring issues that would prevent your bike from starting. You'll have to be more descriptive on exactly what it is doing.

[mack]

actually

after looking at your last picture, that looks like the leads for your rear brake light indicator.

[Sup3rman86]

Awesome, I appreciate the feedback, I'm wondering if anyone can take tics of what I'm asking about showing these wires connected? That would be a huge help