1979 XS1100 Not a XJ900 but it will do for now

The left side cover has two slots on the top that fit into the cover holders on the frame. One of them was broke, so got out the old solder gun and broke up some PCV pipe and got to welding. It has been some time sense I have tried to do PCV welding, but it worked out well. I will start to clean the bike up a little more, de-grease it and power wash it from the seat down. I need to take the 4-1 off and paint that too, as it looks a little aged. Found four air box to carb clamps that I can use as this bike didn't have them when I picked her up. Need to do a little more test riding to see if I will keep this bike or the XJ750 Seca that is now running so well. Sit on (seca) or sit in (special) hmm.

 

XS is back on the lift, one of my carbs, #3, seems to be leaking a bit....hmmm. I guess need to pull them again and do another check. The bike sure does run well though, started right up and even purrs well. One of those nasty rainy days and sense I decided to part with the BMW, want to get this bike running well and get that pesky oil light taken care of as well.

 

Let me know if you decide to send the 1100 down the road...

 

I still have a few bugs to work out of here. I will be doing that today sense it is such a nice day outside..lol. Petcock rebuild kits are ordered. I will be pulling the carbs and setting the #3 carb bowl height again. Drained oil as it is now contaminated by gas as the petcocks failed and well you know the rest.
Will be easy to access the oil sensor with the carbs pulled this time. That is the silver lining I am looking for.

 

What you gonna do once you get low on fuel and have no reserve?

 

I keep my eye on the mileage and fill up round about every 100 miles or so. Seems to be working so far. Is that ok?
I think now that you've come to mention it, i start it off on PRIME and then switch over to ON when down the road.

 

# 3 and #1 were wet set off. #1 I understand, that is the one that I had to solder the float back on, so that needed a little extra tweaking. So carbs are back on and ready for the tank. The "Octo" is gone, that is just nuts. Once the rebuild kits are in place I will just turn the gas off every-time I stop the bike. I do that for all my other bikes that have that feature anyway. That and wet testing "should" stop it from running into the intake.

The oil light is kicking my butt! Swx is good, tested with multi meter and just light pressure, swx works. The BK/R wire I have traced out to the headlight bucket going into the three lights of the panel. Power has to be coming from the ignition swx so that will be the next step. Only one wire has power in the connector, the Green and that should be my running light. Guessing that has something to do with the ignition swx. Shorting the wire at the oil swx does nothing. There is good continuity from the oil swx to the bucket connector.

Green is for the running light in the back (that is also not work but a good bulb), so it might be the ignition swx? All the wires running away from the main wiring harness are good and have checked the ckt with a wire from the Bat.

Oil light will not go out if open or sorted to "-" bat. Rear running light will not light even though bulb is good and ckt is good to bucket connector.

 

I just found a way around the plate light. I ran a jumper from the hot leg of the turn signal connection. That way it is still fused with the signal fuse and work with key on. As for that oil light, I really don't want to pull the bulb but this is kicking my butt. What is causing the ckt to just stay lit all the time?

Removed the 4-1 exhaust and sanded it, put a good coat of heat paint on it. Letting it dry for a few days and then I will put it back on the bike. Petcock parts will be here by Friday. Need to do more research on some other sites to see how or if they fixed the light. I have a good path to the light bucket and the oil swx works fine. Looks at the schematic and found the brown wire that powers everything in the interment panel is the power source.

 

Still waiting for the petcock parts but this is the pic of the mod on the LSU on the bike. Hope this takes care of the oil light issue. Cut away the insulation on those two wires, soldered them together and then added liquid tape.
DSCN0280 by Tim Brown, on Flickr

 

After rebuilding the petcocks they seem to work well. There was still more junk in them even though I had thought I cleaned them out. Anyway, they work well now but I will only be using the rear nipple. That nipple is the on and reserve, the front is for prime. I got rid of the Octo mess so the on and reserve will work as a prime would, so I can reduce the working parts and reduce the amount of fuel lines. Like many of te XS1100 folks have said, I will run the left petcock to the right carb bank and so on.

The speedo is not working as well as I would like it to. I also had a screw come off the face plate so I needed to get in there. These are factory sealed units and I had to go to youtube to get some instruction on how to brake in. After a lot of simple bending the metal ring came off and I was able to get to the face screw back in place. Cleaned the speedo and tried to lube the needle shaft but not too sure it it will loosen up with use. Used a drill to test the speedo and it is working just in the low MPH range is very sluggish.

 

XS650 1977 and newer, XS750, XS850, XS1100 all have the same speedometer. Only the top speed is different.

 

Thanks, if she does not work I will have to find a replacement. End of the project is coming up, dragging my feat a little bit not wanting it to be over. I could go nuts with the chrome and really cleaning it up, but that is not really me. I love to bring them back to life!

 

Took her for a nice little ride, about 10 miles today. I think I have the jet set a little lean, as when I get on her after 5 K RPM she does not seem to want to go. Either that or I will have to go up one or two on the main jet. I have no idea if the PO ran her with the current jet set up with the UNI air filter and the 4-1 exhaust.

As for the speedo, it did work today, not as fast as the newer bikes but I could tell I was going aprox the speed limit of the road. The tack was a little jumpy but that could resolve its self as well.

Going to pull the plugs in the morning and see how white the plugs are. I am guessing it is too lean on the top end. I might have to pull the carbs again or make sure that my fuel lines are not hindering the flow of fuel. I know the carbs are wet set right, so they are not starving for gas because of the fuel height.

This is a nice road bike and feels really good on the back Wisconsin roads. Not as good as the BMW I have been working on but that is like comparing apples and oranges.

 

Sometime you should bring one down and ride the kettle moraine with me...

 

The tacho could be jumpy because of a faulty reg/rec or more commonly the connector from the reg/rec to the alternator. It can get hot where the connector joins and starts melting it.

 

It seems the only real issues with these bikes is the electrical issues. I still can't track down that oil light issue. I have no idea how it is grounding out and keeping the light on. I will just keep an eye on the oil and ignore the light.

Tail light and headlight bypass. Light relay and Reserve lighting unit removed. I have to say the bike does drive very nice. It will stay with me for a while.

 

Once sorted, the electrics on these are reliable. Due to fire, I put a used harness on mine. Now, I’m dealing with corrosion issues. The one issue with these is the flexing wires in the ignition advance. They break. I can think of no other chronic issue. In you case, someone futzed with it. My pressure switch went bad and I had to replace it.

 

I wish it was the pressure swx, but that is working fine. I have traced it to the warning light panel and that is where I stopped. I just figure it is better to be left alone at this point. Easy to see the oil level from the side and I always check that before I ride. I know it is not the best but for now it is just to get me by. Still a few little gremlins to chase down.

 

Took her out for a good ride today, wow does she have some get up and go. Still wondering if the sitting in bike is for me. I think I might have to send her down the road. I will ride her a little more and then see if the XS or the Seca wins for my Yamaha ride.

 

I would venture to guess that the 1100 has more get up and go but the seca is more nimble?

 

Superbike bars, rearsets from Fast From the Past, and reupholster the seat to look like this:

 

^ That is a nice looking seat. I took the bike for a longer right and the power band on the low in is great. I am still having issues above 5K RPM. I am guessing that the main jet needs to go up at least one size. I think the PO changed out the air filter and put a 4-1 on it and never changed the jets. I adjust the pilot jet again and see what I come up with.

I also am confused why after the carb cleaning to include the throttle body seals I have some idle issues. It tends to hand around 3k.

That 4-1 is a LOUD exhaust though...lol

 

texavina.com has seat options for '79 Special.

 

^That is a nice looking bike, I could understand that seat and handle bar choice. One would think the for rest would have to be moved bad a bit but I guess it would depend on the person.

 

Mind if I show you mine? I sculptured the seat myself but had it recovered professionally.
WP_20190406_13_57_48_Pro_LI by Billy Bananahead, on Flickr

 

I am liking the way those straight bars look on this bike. I see you have modded the front end with some blue dot calipers, do tell what you have done to that front end. Brakes and rosters really nice.

 

Thanks Tim. The handlebars are 7/8 inch Renthal motocross, the forks and wheel are from a XJR1200 and the brake calipers are from another Yamaha, probably a first generation XJR1300 or R1 or something. The headlight is a 2H7/2H9 XS1100 square type. Rotors are by Japanese firm TourMax and master cylinder another XJR1200 item. Almost forgot, there's a small spacer between the top yoke and the top bearing.
Also unlinked the front left brake and the rear so that each brake lever operates it's intended calipers.

 

The last photo I posted, and this one are from the Texavina site. It just shows how you can modify the bike just a by opening your wallet. With just the seat and bars changed, the visual change is pretty dramatic, IMHO.

 

Holy moly, that first Texavina seat looks awesome! What a huge difference to the bike!

 

Unfortunately, Texavina doesn’t have any seats for XJ models. They have the XS line covered well.

 

Torozzi rearsets for XS1100 Sport should fit the Special. I have yet to try it. FastFromthePast.com is the Torozzi source. They also have a fork brace and fork tubes. That machine can get an easy makeover without cutting anything up.

 

Now that the BMW is off getting worked on, I got time to work on the XS! I turned the petcocks on to prime them and #3 started to leak. I need to order a rebuild kit for the needle valve, the one that shuts off the fuel when the floats rear their level. I know I am running a too low of main jet with the UNI filter and the 4-1 Kerker pipe. I can't remember how many I need to go up with the main. The stock is 137.5. I am guessing +3 with both the air and exhaust mods? Making it a 140.5

Okay, 4 rebuild kids with 140's on the way. Hope this does it. I will have to change out the seat and also the bars. Coming along with that will have to be the brake lines, if I change out the bars I am sure the stock stuff will no longer fit correctly.

 

Pulled the carbs today, I don't mind pulling them on this bike, lots of room when the air box is pulled back. The needles jets seem to be okay, but no way are the old ones going back in. Once the new kit gets here new main 140's and the new needle jets go in.

The plug boots had tape on them, pulled the tape off and found out why. The #4 was broken so bad that the tape was holding it together. The #1 was close to the same, 2-3 were good. So new boots and I would guess some new plugs are in order too.

Painted the header too, will see how that stays on with heat. Need to do more painting of the rear hub too.

 

What paint did you use?
Did you scuff up what little chrome was left on them?

 

k-moe, you are right to ask me about the paint, I suck at it....lol. I used an exhaust paint from the auto store just for exhaust. I went with a ceramic mixed paint. I did sand them down and clan them off the bike. Once I got them on the bike, they didn't look good in the aluminum color, so I hit them with semi-gloss black hi temp after that. We will see how long that lasts. The pipes were well rusted to the point of little pitting. They are in over all good shape.

 

As long as you did some prep work the paint will hold up for several years. It might even be there arfter the pipes have rusted away.

Based on your concerns, I was concerned that you might have used ordinary enamel.

 

It has always been a issue with me, painting that is. I would love to sand down this tank and get rid of all the little blems in the tank and some of the surface rust that will eventually turn into a issue. I just think when I try to paint it is either too humid or it is just me. I never seem to get the paint the way I want it and it seems to come out foggy looking.

I have not tried that clear coat that holds up against gas yet, that could be the ticket. That and making sure I wait long enough to let the paint dry. I do think this tank needs to be done and the BMW I am working on should be done too.

 

Got me stampeded! I put the 140 mains in and also re-ran the fuel lines so I know they are not hindering the fuel low. I start the bike, runs great, comes off of choke in a very short time and runs well. Then take it on the road and give it a twist and it is almost like there is a governor on it at 5k! As stated above, I took the carbs to church, normally it would be a low rmp issue or idle issue, not the case.

Are my secondary jets not even kicking in? If so why not? The new larger jets, the very clean emulsion tubes, just a head scratch-er for me. Hit he pips with a IR temp guage and all the exhause pipes were very close. Nothing cool so all are firing and running.

It just dawned on me, ignition advance? I think these bikes had issues with one of the wires breaking or cracking...I am guessing that would make it top out in the RMP range?

Any advice would be great...anyone think it might be the advancer?

 

That fits. I once had a problem with my old truck that I thought was a plugged-up fuel filter (that problem had occured several years before, so naturally I went straight back there). She would bog down at 3,000 RPM (smallblock V8). Turned out to be a hidden crack in the vacuum line to the advance diaphram.

 

I think it is the vacuum advance but now to play around to what port to run the vacuum to? I currently have it hooked to #2 carb as I think that it how it was from factory. I removed the Oct fuel thing and have plugged that vacuum port, I think I will try to change the advance over to that nipple and see if it works better.
DSCN0323 by Tim Brown, on Flickr
DSCN0329 by Tim Brown, on Flickr

 

That's right mate. The take-off spigot on number 2 carb, NOT the carb to head manifold.
If you have it connected to the carb to head manifold the vac advance will just rattle and jump around like a good 'un.

 

May not hurt to make sure the mechanism itself moves freely and isnt sticky causing inconsistent timing. Making sure the line is hooked to the proper location would definitely be my first go to though also

 

Thanks for the response, I made sure the hose was good and watched the timing advance with vacuum applied. I cleaned the timing wheel and lubricated it with PB blaster on a "Q" tip, I didn't want to over do it.

I am stepping away to try to think this through. Can't be anything else has to be the timing issue. Working on another bike for a while so I can come back to this and maybe have a fresh set of eyes to make it work. I sure love the power this bike has when you roll on the throttle, just wish it didn't stop at 5KRPM.

 

It has been a while sense I had room for the old XS in the shop. I got to her today! I found the issue with the 5K issues, how about a kinked fuel line on both side! I can't beleive I missed that when I was trying to rout the fuel line. So, new fuel line is on and I am getting some alternate petcocks and we will try this again.

I did set the timing, it was a little off, closer to the "T" mark than to the "F" mark.

 

New fuel line with filters are in, looks much better under the tank. The issue is still there for the 5k RPM issues. I will take a look at all the wires going to the ignition pickup tomorrow. I only looked at one of the wires that was broken, I will check the rest now. That is the only thing I can think of that is still holding this bike back from yanking my arms off. This is a common problem with this bike as the wire are so small and the vacuum advance makes the wires mover all the time. Bigger wires and make sure they are all connected well and I hope that will fix it.

This will be more helpful to show what I need to do.
http://www.xs11.com/forum/showthread.php?t=543

 

Well, now it has to be the vacuum control system. I tested and replaced the ends of all four of the pickup wires. Tested them back to the connector behind the fuse box holder. So they only thing left is the vacuum control. Not looking forward to finding one of those for this bike. I don't want to spend the $$ for the alternative, the electronic version for $300 plus.

 

Check Partzilla or your favorite OEM parts source. The vacuum pot may still be available.

 

Gremlins are still winning this long term fight. I got a chance today to take apart the vacuum and mech timing advance. This is the mech that looks good but I took it off and cleaned it and put a little Mystery oil on the springs and pivot points before she went back in place.
Mech advance by Tim Brown, on Flickr
The pickups were also cleaned and new connectors were installed with larger wires.
Pickups by Tim Brown, on Flickr
connectors by Tim Brown, on Flickr
New crimps by Tim Brown, on Flickr
The timing plate never moves when you removed the advance. The bike tired right up and sounds good, but the 5K threshold is still there. So I have two options.
1. I will be pulling the carbs again to see what could be wrong? I measured the temps of the pips and they are all very close to being the same (IR) temp gauge.
2. The CDI or brain box could be done.

I will have to do some more reading to find out why this bike would have two ways for it to get it's timing advance. Vacuum and Mech force both are on this bike. This thing pulls like a bears from 1.5K to 4.5K or so RPM and then it is done in all gears.

 

You get mechanical advance when you crack the throttle and RPM climbs. The vacuum advance will operate at cruise. The vacuum advance should improve fuel economy.

Make sure your new wires don't restrict movement of the mechanical advance.

By today's standards the XS1100 is a turd, but in its day it was a powerhouse and briefly, king of the hill. It's still great fun to twist the throttle and it is a bargain as compared to a GS1000 or KZ1000. Once sorted, it's a reliable rocket.

 

I made sure that I have plenty of room and that the wires are secured and won't get cut or rubbed on by the moving parts in that area. Went through the carbs again to make sure the right carbs for the right bike, check. Right jets in those carbs, again check. Are the diaphragms are good as new...no but they are working and holding when hole is plugged up front.

So the mech advance is working just great when it come to the bike sitting and just flicking the throttle. That is why I was wondering why when in gear the bike hits that 5K wall. All things are still pointing to the carbs. It could be I missed something. I will give it a day and come back to it.

Here is the TDI and it looks like it might have have been worked on before? Those connector pins joints look like they need a little heat applied to them? If the TDI was bad, the bike would not run through the full range of RPM's when sitting. So the box should be good.
20190829_081953 by Tim Brown, on Flickr