New member here, just bought an xs1100 special

[TheNannerpus]

***I'm gonna just keep updating this post with the latest going-ons of this newb's bike project***

I've been heavily browsing these forums for the past week, so I figured I should join up.

I just bought a 1980 XS11 Special with 33k miles on the clock. It wouldn't even start when I picked it up, but it looked fairly clean. The PO said it was a barn find in northern WI that he paid $1k for earlier this year and spent several hours cleaning up. He had only ridden it once, but was having fuel leaking from the fuel diaphragm and was frustrated with it. He had the tank and side covers painted and got new emblems for it.

I wanted a project bike so I gave him $1300 for it. I figured Google's value search was fairly accurate and thought it was a fair deal. (?)

I got it home, disconnected the octy setup and tried starting it with just the fuel remaining in the lines, full choke. That worked! It idled, but any amount of throttle and it bogged, absolutely no revving. Taking it off choke, it died. Once it warmed up, it died. I also noticed the diaphragm's rubber gasket was rotated out of alignment, meaning the holes in the gasket were not lined up with the little raised dots. I can't help but wonder if that's why it leaked.

So off came the carbs and here I am. This seems like a good place with a good bunch of contributors that know a heck of a lot more than I do.

[TheNannerpus]

EDIT: NEVERMIND...I found the help section

Also, where do I edit my signature line? I didn't see 'Signature' in the profile section.

[Bax]

Welcome to the club. Looks like you have a good starting point with the bike in decent shape. I'd suggest returning the carbs to known OEM starting points with genuine Mikuni jets and needles. There are a lot of inferior "replacements" that can cause the fueling symptoms you describe. Rebuild kits for the octy are available, diaphragms are drop in, but need a larger o-ring to seat the valve properly.

---Bax

[bikerphil]

where do I edit my signature line? I didn't see 'Signature' in the profile section.

Click on your name in the top right corner, click user settings, click profile, click account, scroll down to edit user signature and click.

[Radioguylogs]

That's an especially nice bike for the price.

It's really unusual the exhast headers are so nice (not rusted).

Welcome to the forum.

[LoHo]

Congrats on your purchase...be prepared to become an expert on carb cleaning...

[TheNannerpus]

Congrats on your purchase...be prepared to become an expert on carb cleaning...

I did clean those things out, and they didn't seem all that dirty. But I went through a whole can of chemtool anyways. The outsides were far worse - a product of that leaking octy spraying gas all over, I think. Even the inside of the air box was sooty and greasy. I spent several hours degreasing that bike 😓, not perfection, but definite improvement.

The biggest PITA to me was getting the air inlet boots reattached.

My reinstall process was

1. Install intake manifold boots
2. Try installing airbox
3. Uninstall intake manifold boots
4. Retry installing airbox
5. Install intake manifold boots again
6. Squeeze in carb, attach to manifold boots
7. Fight for well over an hour with attaching those 🤬 air box boots

After all this it started up aaaaand........leaked like crazy from that darn octy, just like before I tore it apart. I have questions on that thing that I'll post separately.

At least it idled.

[cajun31]

I did clean those things out, and they didn't seem all that dirty. But I went through a whole can of chemtool anyways. The outsides were far worse - a product of that leaking octy spraying gas all over, I think. Even the inside of the air box was sooty and greasy. I spent several hours degreasing that bike 😓, not perfection, but definite improvement.

The biggest PITA to me was getting the air inlet boots reattached.

My reinstall process was

1. Install intake manifold boots
2. Try installing airbox
3. Uninstall intake manifold boots
4. Retry installing airbox
5. Install intake manifold boots again
6. Squeeze in carb, attach to manifold boots
7. Fight for well over an hour with attaching those 🤬 air box boots

After all this it started up aaaaand........leaked like crazy from that darn octy, just like before I tore it apart. I have questions on that thing that I'll post separately.

At least it idled."

I was looking at the pictures you posted. Unless you have reinstalled the brass plugs (which I don't think you did) over the pilot screws then you have not yet cleaned the carbs well enough. Those plugs need to be removed so that you can inspect the pilot screw, spring, washer and rubber o ring in each one. The rubber o rings are probably old and crusty and need to be replaced. If you pursue that job what I have found to be the safest way to remove the plugs is to take a 1/8" drill bit and drill through the hole on the plug until the bit just gets through the brass then take a 4mm tap die and screw it into the plug. It will bottom out on the top of the pilot screw. Just keep turning it will also lift that plug straight up out of the pilot screw tunnel with no danger of breaking the tower. Once you have all the plugs removed, before removing the screws, lightly seat each screw one at a time by turning them clockwise until you just feel them seated. Important ... count the number of turns you go to seat each one and write that info down. You will want to set them the same when you reinstall them with new o rings. That will put you back to very close to where you are now and the bike should sitll start and idle correctly. Follow the tips on your other post concerning the OCTI and you will be back in business.

[TheNannerpus]

cajun31

Oh man, thanks! I have a new clue to solving this bike's problems. I didn't know about this. I wondered what all the extra parts in the carb rebuild kits were about 😳. Sucks that I have to pull the carb again, but I need the practice.

[DiverRay]

To pull the carbs:
1. Remove ALL the bolts holding the airbox on.
2.Loosen all the clamps holding the carbs on.
3. Remove the fuel lines and octy if you are still using it.
4. Remove the breather tube from the airbox and engine.
5. Pull the airbox to the rear of the bike as far as you can.
6. Grab the carbs from both sides, twist the rear down, and lever out the LEFT side of the bike.
7. disconnect the throttle cable.
Reverse order to install.

[Bax]

Just going to add to Ray's procedure. Taking the lower air cleaner off the air box gives a bit more room to move the air box around

---Bax

[2WheelFun]

An Aussie, the barefoot mechanic has an excellent YouTube video on carb removal/install. You may find a tip or two on it.

[cajun31]

To pull the carbs:
1. Remove ALL the bolts holding the airbox on.
2.Loosen all the clamps holding the carbs on.
3. Remove the fuel lines and octy if you are still using it.
4. Remove the breather tube from the airbox and engine.
5. Pull the airbox to the rear of the bike as far as you can.
6. Grab the carbs from both sides, twist the rear down, and lever out the LEFT side of the bike.
7. disconnect the throttle cable.
Reverse order to install.

Ray when you say remove the octy are you telling him to completely remove it? It already clears everything as it sits? I might tell him to take the Octi screw out to free it up a bit ... but complete removal is unecessary. I have never had to completely remove the breather tube to get the carbs on and off. Maybe my tube is too flexible though. Probably a good idea if the tube if fairly stiff though. As for the airbox I agree with Bax, much easier to get on and off with the lower half removed. Also helps to do that so that you can get by without removing the breather hose. As clarification when Ray says to move the airbox as far to the rear as possible, you must first pop all the intake rubbers off the carbs. I do that step by pushing the airbox forward and down in one good strong motion. Then you make sure the metal bracket that holds the airbox in place with a bolt in the frame clears the frame in the same motion. You can then pull the airbox back and out of the way without taking it all the way off the bike. The air snorkel will slide back enough and then you simply rock the carbs out of the intake manifolds and then work the carbs out to the left side of the bike. As Ray stated ... make sure you take the throttle cable loose before trying to take the carbs all the way out.

[DiverRay]

I've NEVER liked the octy! My MNS was the only bike I kept it, the rest, tossed it. My current ride is a '79 Special with a Standard tank. No octy, manual petcocks. When I put the stock tank back on, no octy. Just my personal preference.

[cajun31]

I've NEVER liked the octy! My MNS was the only bike I kept it, the rest, tossed it. My current ride is a '79 Special with a Standard tank. No octy, manual petcocks. When I put the stock tank back on, no octy. Just my personal preference.

You made me chuckle. Maybe that is the reason I like the octy. I own three MNS.