81 XS1100 Midnight Special will not run.

[hemisxpck]

Hello everyone. I have 1981 XS1100 midnight special that has not ran in 15 years, I went through the the petcocks and the carbs (except for the recently discovered pilot circuit according to one of the threads.(no idea what it looks like). I got it running at one point and it would idle but no power if you try and ride it. I went now I cannot even get it to start with out giving it a lot of throttle. I replaced the fuel lines with aftermarket line and tried to keep them as close to the same length. I am completely stumped. I checked the vacuum advance and the coils and they seem to be working fine. Thank you in advanced for your time and knowledge.

[JeffH]

Just a couple of initial thoughts ...........

> how much rust is inside the fuel tank? Did you install any fuel filters?
> Are all 4 header pipes getting hot? Can spritz some water on them to check. (if you can identify what pipes got hot that would help, although you say not it won't even start back up without a lot of effort).
> Did you set the float heights? and to what mm?
> Plugged up pilot jets do what you are describing. Likely need another real good carb cleaning. And get those pilot jets out and clean them and blow carb cleaner through ALL the passageways.

Does changing the choke setting make any difference when you tried to ride it? Likely the short ride just moved crud in the carbs and now the passages are clogged again.

Jeff

[hemisxpck]

Cleaning the tank was the thing I did, the only filter i saw was on the petcock part inside the tank. All 4 manifolds are getting hot. I am going to have to go in an reset the float height, I left the height where it was when i took the carbs apart (or so I thought). I did not try the choke as I was riding it. I will be taking the carbs back off tomorrow and go through every thing.. Thank you for your response and help.

[mack]

Carbs

I think Jeff is right. The carbs are really the heart and soul of these bikes. They need to be spotless inside for the bike to run and perform as designed. You didn't mention if you used an ultrasonic cleaner. Something that has sat for that long will need a very thorough cleaning so a full tear down would be required (carb cleaning 101) bench sync and float (fuel height) adjustment before you even think of mounting them.

[hemisxpck]

I never thought of using an ultrasonic cleaner. I will do that tonight. Thank you for the idea.

[soccer4m]

Ditto

Ditto,, BUT after all that carb cleaning definately install a GAS FILTER, inline, in each gas line. The carbs have to be spotless, all passages clean and it will run like a beast. Get a couple cans good carb cleaner, a table to spread out the carb parts, a spring loaded punch to pop off the float, a couple cotton ear cleaners, good tunes and go at it.......before you pop the carbs in,
1.the gas petcock on prime and empty into a small cup to make sure the tank flow is good,
2. check the diaphrams for pinholes{ shine a flashlight in the dark at them},
3. reassemble carbs

4. pop in the carbs, pray for the carb gods to be good,,,,,,,,,,Mike in Sun Diego

[mack]

Carbs

Since it's a café style I'm sure the air box is gone and you have pods. But before you install the carbs it wouldn't hurt to look at the clamps that hold the carbs in the intake boots. Change or replace the screws if required. Always a good idea to ensure the boot bolts are tight as well. Vacuum leaks are a bitch when tuning. It's also a good time to inspect intake side of the motor for leaks etc.
Before you install the carbs, make sure to do a bench sync.

[Aches n Pains]

If the 81 is the same as the 79, you might consider removing the octys and re-plumbing the carbs. Whole setup might cost $10 - $20.

fter removing the Octy, this is how I route the fuel lines on my '79 Special. Solved a bunch of problems related to leaking, overflow, gas in the sump, etc.

https://photos.app.goo.gl/hBPVvSbaII6s2gki1 I apologize for the link but since Photobucket crapped out I just gave up and keep my photos on Google +.

Left side to carburetors.

"X" fitting so both carbs are fed by both petcocks - brass fitting from ebay (aquarium item)

Inline filter as mentioned in several posts.

Briggs and Stratton shutoff valve so gas can't flow regardless of condition of petcock. Inexpensive though not elegant.

Right side to petcocks

Of course, all joints are clamped with clamps like shown in picture. Note that I just put this together for demonstration purposes. Individual hose pieces need to be cut to fit your preferences.

May not be the prettiest solution but it really works well.

[hemisxpck]

Thank you All for the information. It is a great help. I really love this community and hope to be as helpful as you all have been someday.
I took the carbs out of the ultrasonic cleaner last night and will put them together tonight. I have replaced the intake boots between the carbs and the motor. I took the octopus apart and found the diaphragm to be shot, so I am going to reroute the fuel lines for now with filters. and as Mike suggested I will prey to the carb gods







I have a stock 81 midnight special (the problem child) and a 80 cafe that is running flat slides.

[Eastcoaster]

Keep Us posted

Keep us posted If you get frustrated I am a few hours away and have done a few of these. I have enough spares can swap out anything and diagnose.
I have got a few back the way they should be.
Eastcoaster

[mack]

Octy

Getting rid of the octy is one of the best decisions you'll make. Simplifies the plumbing and they were always prone to failure. Gave a false sense of security and just a big pain in the butt. Make sure your petcocks can shut the gas off and get used to just turning off the petcocks before you step off the bike. None of my XS's have them anymore.

[hemisxpck]

Thank you all so much.

I am sorry on the tardiness of this post. I want thank each and everyone of you for the guidance and knowledge you have bistoed on me. My xs1100 now runs like a dream. Thank you all again.