new problem...got caught in the rain... (Electrical?!)

[DiverRay]

Start with easy. Check the vents between 1/2 and 3/4. These are the top hoses and MUST be open! Next is look at the fuel lines, the bottom hoses, and make sure there are no kinks. If you have the stock petcocks, put them both on PRIME and see if it runs better. If prime works, pull the tank and CLEAN the outside of the petcocks. There is a little tiny vent hole that if plugged may cause the fuel to NOT flow. Prime bypasses this.
Let us know what you find.

[3Phase]

Book 'em, Dano!

I feel your pain because I don't have a car either, my bike is my only transportation and it's down for repair right now.

The backfire could have been a lot of things, probably from the TCI kicking a spark at switch-on or switch-off when there was fuel in one of the cylinders. It can be pretty spectacular.

Anyway, I'm starting to agree with Dbshea and it's not primarily an electrical problem. I've been trying to have you check simple electrical things that take more time to write and to read than to perform while you work them from the outside in as you remove covers and parts:

Side cover
Seat
Tank
Valve cover

Before you dive in much further you're going to need some manuals. If you don't have them already, here are a couple of links to the main '78 shop manual and the '80/81 supplement:-


XS1100oemManual.pdf 182MB


XS1100H-SH-LH_G-SG-LG_Service_Manual.pdf 35MB

I hope the share links work, Microsoft and Onedrive seem to be having DNS issues today.

Edit: Backfire/single spark is one symptom of a bad TCI.

[DiverRay]

OK, I didn't see that you have the SPECIAL, so the Octy has the vacuum fuel shut off. You have the top vent hose if you are using the '79 carbs, the '80 carbs vent through the bell on the air filter side.
DO YOU HAVE MORE THAN A GALLON OF GAS IN THE TANK?!?! The specials will NOT run well when they get low on fuel! I know, I had a MNS for about 6 years.
You can still try running on prime and see if it runs better, but my guess is a pinched fuel line, just because I did it myself more than once..(I'm a slow learner sometimes)

[ERM83]

I feel your pain because I don't have a car either, my bike is my only transportation and it's down for repair right now.

The backfire could have been a lot of things, probably from the TCI kicking a spark at switch-on or switch-off when there was fuel in one of the cylinders. It can be pretty spectacular.

Anyway, I'm starting to agree with Dbshea and it's not primarily an electrical problem. I've been trying to have you check simple electrical things that take more time to write and to read than to perform while you work them from the outside in as you remove covers and parts:

Side cover
Seat
Tank
Valve cover

Before you dive in much further you're going to need some manuals. If you don't have them already, here are a couple of links to the main '78 shop manual and the '80/81 supplement:-


XS1100oemManual.pdf 182MB


XS1100H-SH-LH_G-SG-LG_Service_Manual.pdf 35MB

I hope the share links work, Microsoft and Onedrive seem to be having DNS issues today.

Edit: Backfire/single spark is one symptom of a bad TCI.

I have the service manual, but not these...thanks, Scott!!

OK, I didn't see that you have the SPECIAL, so the Octy has the vacuum fuel shut off. You have the top vent hose if you are using the '79 carbs, the '80 carbs vent through the bell on the air filter side.
DO YOU HAVE MORE THAN A GALLON OF GAS IN THE TANK?!?! The specials will NOT run well when they get low on fuel! I know, I had a MNS for about 6 years.
You can still try running on prime and see if it runs better, but my guess is a pinched fuel line, just because I did it myself more than once..(I'm a slow learner sometimes)

I'm gonna go outside and try putting it on prime...I cleaned up the petcocks about a month ago, so that could be something. However...the bogging once it warms up has me worried that it's the valves. Is there any method to checking the actual TCI?? As I said before, the plug checks out perfectly. I have plenty of spark (and, yep...shocked myself a bit in the process ), put new plugs in, and still runs like crap. OH...there's definitely plenty of fuel in there...no lines are kinked, but I have to check the T's / vents, just to make sure. Will report back shortly!

[ERM83]

AND I forgot to mention that I'm using the '79 carbs!

[DiverRay]

If you are using the '79 carbs with an 80 airbox, that may be your problem! The newer airbox has a nipple for the vent, but it is NOT drilled through, so no vent. You can try un-plugging the lines off the airbox and run them open for a little bit. If that helps, just put a cheap gas filter on each vent to keep the dirt out.

[ERM83]

If you are using the '79 carbs with an 80 airbox, that may be your problem! The newer airbox has a nipple for the vent, but it is NOT drilled through, so no vent. You can try un-plugging the lines off the airbox and run them open for a little bit. If that helps, just put a cheap gas filter on each vent to keep the dirt out.

I'm running pods for the time being. I want to get an airbox eventually, but I'd already had these set up for my current exhaust/ intake. Also, YOU told me to use these, Ray!

So, tried it on prime...still the same. This is making me CRAZY...

[DiverRay]

Then I would pull the valve cover and check clearance across all of them. I know it's about 1.5 hours, but you are there. Oh, if the engine is warm, the clearance will be less than called for, but if the bottom spec is 0.012", should be no more than 0.010", as an example.

[ERM83]

I definitely need to check the valve clearances, but my tool is at the garage...8 miles away. It just doesn't make sense to me having a VERY SUDDEN power drop like that, and it being a valve problem. NOT questioning you all in the slightest...I just can't get over the fact that it keeps acting up when it's wet out. I'm on the brink of insanity right now. I'm going to yank the carbs, and check them. All of my electrical connections are fine...WHAT THE HELL IS WRONG?!?! AAAAHHHHHHHHHHHHH.....

OH...BONUS PROBLEM: MY THROTTLE CABLE IS ABOUT SCREWED NOW, from cleaning the kill-switch circuit. YYYAAAAAAAAYYYYY.... *GRUMBLES WHILE TRYING NOT TO BREAK SOMETHING*

[3Phase]

Have you looked in the pick-up coil harness sheath down by the Neutral switch? Peel back the wrap and see if there's water in the harness.

[ERM83]

Have you looked in the pick-up coil harness sheath down by the Neutral switch? Peel back the wrap and see if there's water in the harness.

Yep...just actually got done doing that. I'm taking the carbs off right now...I NEED to get this figured out. Exhausting every option before I go digging into the head. I wish I could at least get it to the garage....

[3Phase]

Hmm, before you get into the carbs, take the wire off the Neutral switch and use a pin or something to take the spade out of the connector shell, then just let it hang.

You won't have a green Neutral light for the test but it'll eliminate the 12 Volts from the Neutral switch circuit.

[bikerphil]

You know there is that mystery gremlin that cuts out two cylinders in heavy rain. It is temporarily solved by grounding the neutral light wire, this is why the bike runs fine in neutral and dies when dumped into first. BTDT many times.

[skids]

I'm running pods for the time being. I want to get an airbox eventually, but I'd already had these set up for my current exhaust/ intake. Also, YOU told me to use these, Ray!

So, tried it on prime...still the same. This is making me CRAZY...

79 carbs need to be vented. I use pods too, but the breather hoses need to be routed to a crankcase filter or something. You cant plug them off.

[3Phase]

I was wondering about the carb vents too or maybe the pod lips blocking the air jets when I saw the note about '79 carbs but that still wouldn't whack the engine when it comes out of Neutral

The Neutral wire is a ground wire and the switch is a ground, it grounds the Neutral light and the wire floats 12V when the switch turns off. I think what happens when it rains or the bike gets gets washed is the junctions for the pick-up wires get wet and share the ground through the Neutral switch.

The ground reference for the TCI is alright with it when the Neutral switch is closed and it's a ground because the TCI is grounded too. When the switch opens the pick-ups get pulled up to 12V and the ground reference is through the other lamps in the lighting circuit, not ground-ground. It'll work but goofy.