1981 XS1100 Midnight Special Slow restoration

[DEEBS11]

Here is my account of the modification

https://xs11.club/forum/idle-talk-forum/xs11-xj11-discussion/871972-78-sidecar-project/page5

[DEEBS11]

These are real Dyna coils 3 ohm. You will need to fab brackets & high tension wires & eliminate the ballast resistor.

https://www.ebay.com/itm/361334844121

https://www.youtube.com/watch?v=YANYAa2LIh4

[Medumdum]

Found this and it talks about pretty much the issue I think I have, but the pictorial they linked to no longer works. I can see how to replace/fix the wires, but I wanted to know how I could properly test it to make sure before I started cutting up wires.

[Medumdum]

Did some more testing, both the coils are good, I swapped the 2-3 coil to 1-4 and bike fired up, so then I swapped the pickup pins on the TCI box and still could only get spark on 1-4, 2-3 no spark, so I’m guessing it’s the pickups or wiring to them then.

I’ve bought a dyna coil for a goldwing before and had to splice the wiring in myself, do they sell a plug and play coil for these bikes for down the line? I would rather not have to cut up the wiring on this bike anymore than I have to. I couldn’t find any OE coils for sale, only used ones or third party. I don’t need them this time thankfully, but would be nice to have a decent one picked out for if the coils go bad.

[DEEBS11]

More on cheap coils

https://xs11.club/forum/modifications/battery-electrical/12806-mikesxs-high-output-black-ignition-coils-bad

[DEEBS11]

Here is an example of a garbage part. I had a similar coil on my KZ750B sidecar rig and it died (opened circuit) in the middle of an intersection during rush hour. I'm sure the wire inside the coil was as thin as human hair to save money. Complete junk.

https://www.ebay.com/itm/27343565800...Bk9SR4KgmbOcYw

[DEEBS11]

Medumdum, the coil is just like the name, a coil of wire. About 3 ohms which is almost a short when measured with a meter. Beware of the new coil(s) you ordered as they are more than likely Chinese junk if they are less than $150.00. Dyna coils (not Chinese copies) are the way to go. Your two cylinder not firing could very likely be a broken wire on the lower left side of the motor in the timing advance unit. This is a common area of failure. It could also simply be a dirty connector in the harness. As you suggested, I would change that oil before I ran the motor anymore. It's old and it's status is unknown.

https://xs11.club/forum/repairs/batt...ders-misfiring

[Medumdum]

One other thing I forgot to tell you. If your carbs were flooding make sure you check your oil. That gas can run down into the oil as well. It sounds like it went in the airbox, the opposite direction but I would still check the oil level smell to be sure. An oil filter and fluid change should be on your check list anyway. Those as well as all the other fluids in the bike. The middle and final drive fluids.

Oh yeah, I did check oil level and it’s good, no fuel smell either. Fluids were all on the plan before getting it on the road proper for sure, as well as plugs, currently there’s some NGK and some champion plugs, I’ll probably just get 4 new NGKs when I do the oil as well.

[Medumdum]

Sorry for the slow updates, had to wait on parts to come in and holidays also took up some time. I got the carbs put back together with new needles and seats, as well as bowl gaskets and no more leaks. Bike was able to fire up and stay running but it wasn’t really running right. Turns out the middle two cylinders weren’t firing. Checked for spark, no spark, and they’re both running off the same coil. Checked coil, and there’s a short, no resistance in the primary coil. Got a new coil on the way. As far as brakes go, I got the front right caliper rebuilt, but waiting on buying the rebuild kit for the rear since it’s a bit pricier than the fronts and property taxes are coming up. The cylinders for both seem to be in decent shape, bike was only sitting 2 years and before that it seems like it was pretty well taken care of.

Edit: just realized I tested the coil incorrectly, so it might not be bad and I need to look further downstream into the ignition system, but at least I know where to look.

[normalthom]

Damn, that's a mountain of great information. Thanks for sharing!!

[cajun31]

One other thing I forgot to tell you. If your carbs were flooding make sure you check your oil. That gas can run down into the oil as well. It sounds like it went in the airbox, the opposite direction but I would still check the oil level smell to be sure. An oil filter and fluid change should be on your check list anyway. Those as well as all the other fluids in the bike. The middle and final drive fluids.

[cajun31]

Thanks for all the advice guys. I haven’t gotten too much done on the bike because I spent most of time just getting this garage tent thing built so the bike would be out of the elements. I don’t have a proper garage so this is the best I could do.

Anywho, I got the carbs off today. Previous owner claimed a shop had gone through them two years ago and got them rebuilt and tuned correctly. With how easily everything came undone I believe it, didn’t even have to tap out the aluminum rods holding on the floats, I was just able to pull them out. The slides and diaphragms were still in great shape, some of the jets were clogged but nothing a bit of chemtool and thin copper wire couldn’t solve.

My main concern now is that the needles and seats didn’t look to be in too bad of a shape. With how badly the carbs flooded, I imagined they were going to look a lot worse. I did already order a replacement for them regardless, but is there anything else that would cause the carbs to flood to the point of also flooding the intake box?

I also pulled the air box itself because I was still looking for the octopus, does not look like this bike has it still. Guy I bought the bike from did say he also has a parts bike I can bring home, so I might try and grab that next week and hope that it still has its vacuum system. In the case that I cannot easily obtain one, how should I hook up the fuel lines so that it’ll still run at least? From what I read on posts where people delete their octopus, I should maybe just cap off the “prime” outlet on the petcock and run the fuel line from the “on” outlet straight to the fuel inlet on the carb?

New air filter, front pads and front rebuilt kit with the stainless cylinders from breakcrafters is also ordered and on its way.

Just wanted to specifically address some of your questions. Looking at the pictures you posted one of the needles looks like the pin in the end of it is stuck down. That happens when varnish gets in them. You stated you will be replacing all of those anyway. When those pins do not compress and release properly they can cause float level / gas level issues. If you have not already done so make sure you read the carb cleaning tip that is posted in the carburetor repairs section Carb Cleaning 101 - XS11.club Forums. Your float heights should be set at 23mm or just go by what Kat says about the plastic floats. the key is to set them all with the float bowl gasket removed. There is another method to set the fuel level and there is another tip Setting the Carburator Float Height - XS11.club Forums but requires additional equipment to accomplish. Hopefully you are keeping the parts from the carbs from getting mixed up. Keep all the parts separated by carbs as you work through them. Float heights, stuck floats open, etc... are the main reason for flooding. Do you park your bike on the center stand or side stand. Parking on side stand can make the floats stick open too, if they are not clean and operating correctly. Your octy is gone by your description so you need to get into the habit of immediately turning your petcocks off when you get done riding. I mean even when you just stop for a minute. Having the carbs cleaned and set up right will help but there will still be no guarantee that the carbs may not still flood. Just doing the simple turn the petcocks off will eliminate that. Like I said in an earlier post your bike looks very nice and if it were me my goal would be to get it back to original. That would include acquiring the parts necessary. The octy can sometimes be found on Ebay. Just buying that part is not all you would need though. You also need to make sure you have the mount bar that installs on top of the number one carb to be able to secure the octy. Here is the octy for sale on Ebay rare OCTY "OCTUPUS" vacuum FUEL SHUTOFF--- for 1980 1981 YAMAHA XS1100 SPECIAL | eBay. You also need the bar you see on the left of this picture mounted on the top right of the number one carb.

Of course you will also need the 8mm screw/bolt washer to secure the Octy.
Why do I suggest the Octy you might ask? If working correctly as the Yamaha engineers devised, it will serve as a shut off for the fuel. When working correctly when you start the bike the diaphragm opens and allows the fuel to flow. When you shut the bike off and lose vacuum the diaphragm closes shutting the fuel flow off. The standard model xs1100's have this same diaphragm built into the petcocks and functions in the same manner. From what you have thus far described you no longer have the octy and it has been bypassed. The long fuel hose from petcock to petcock serves that purpose. If you elect to put the bike back to original the diagram on fuel cock piping Yamaha Motorcycle 1981 OEM Parts Diagram for FUEL COCK-PIPING | Partzilla.com shows you exactly how to route your lines. You will need to also purchase two of these plastic joints Yamaha 3H3-24376-00-00 - JOINT PIPE | Partzilla.com along with the clamps etc. that I posted earlier.

One other tip, When you start on the brakes, do the rear master cylinder first. If you can get it working correctly you can use it to remove the pistons from your calipers. You will see a larger bolt on the side of the master cylinder and you can actually remove it and still operate the rear brake lever to pump brake fluid. The fluid will not just shoot out of the hole but allows you to keep adding more fluid as you need to. I use a cajun injector syringe to squirt more fluid in as needed. Those calipers can sometimes be pesky to remove. I have found this method helpful. The calipers have quite a ways to travel before they pop out. Here are a couple of listing from Ebay that could also help when doing the brakes. Brakecrafters Motorcycle Brake System Reverse Bleed Kit Non Pneumatic Bleeder | eBay, I prefer a mity vac or something similar but it looks like this could work. I also always use some of this grease when reassembling everything. It does not hurt rubber Brakecrafters Red Rubber Grease For Hydraulic Motorcycle Brake Systems Repair | eBay and it also keeps everything coated to eliminate moisture. Just get in the habit of replacing the brake fluid every couple of years because dot 4 brake fluid is hygroscopic (attracts/absorbs water).

Good luck and keep us posted on your progress.

[DEEBS11]

OK These are OEM Yamaha/Mikuni.

https://www.partzilla.com/product/ya...7a911be38f78bb

[DEEBS11]

I stand corrected Cajun31. The main clue is the superimposed part number on the photo. it crosses to a K&L part. Japanese made but not OEM Yamaha.

[LAB3]

If there isn't any heavy corrosion or other physical damage the o-rings and bowl gaskets are all you really need.