xs1100 ignition

[Chadwic82]

Hi everyone, Newbie here. My name is Chad Prater and I had some questions about the ignition box on my 1981 xs 1100. I tried to fix it by re-soldering the connections but still have the same problem. When I read with a multi-meter on the orange wire, it starts out at 11 volts and goes between 2 and 4 volts when the starter is engaged. When I put the multi-meter on the gray wire, it starts at 11 volts and goes down to 8 when starter is engaged. Can anyone tell me if I have a bad ignition box or could it be something else? Thank you!

[DiverRay]

Welcome to the site, first off!
I would start by looking at ALL the ground connections on the bike. Pay attention to the one from the battery to frame, and frame to engine. pull both , clean them, and reinstall with anti-seize compound around the connectors. The next one to fix is on the top of the Reg./Rectifier. There are about three black wires all connected to the screw, and they should be cleaned and installed with anti-seize on them.
Make sure the battery is fully charged, and check the pick-up coil wires at the TCI box connection.

[Chadwic82]

Welcome to the site, first off!
I would start by looking at ALL the ground connections on the bike. Pay attention to the one from the battery to frame, and frame to engine. pull both , clean them, and reinstall with anti-seize compound around the connectors. The next one to fix is on the top of the Reg./Rectifier. There are about three black wires all connected to the screw, and they should be cleaned and installed with anti-seize on them.
Make sure the battery is fully charged, and check the pick-up coil wires at the TCI box connection.

Thanks for the welcome. Battery is new and has full charge,checked the wires at the TCI & I'm gaoing to check the grounds this weekend. Would the grounds cause just one coil not to fire? I would think you would lose both.

[natemoen]

If the voltage drops below 10.5 at the tci then the tci won't send the signal to fire anything.

[bikerphil]

Would the grounds cause just one coil not to fire? I would think you would lose both.

Might be a bad P/U coil wire? that would cause loss of 2 cyls.

[oldyam80sg]

Diver Ray-The grey colored anti-seize correct?I know they make a
copper color but have been told you don't want to use that or die electric grease-Is that right?

[BA80]

HEY! Welcome Chad. Always glad to see another Okie.

Phil is right, sounds like a pickup wire. That's a pretty common problem.

If you still think it might be the TCI I might have one here. I'll need the #s because I think they used 2 different ones in 81 depending on the date of manufacture.

I think the late 81s had the same ignition as the XJ. Not sure of that though.

Got several 2H7 boxes laying around.

Holler if you need help. I ain't far away.

[cywelchjr]

I'm pretty sure all the 81's use the same TCI which is different than the XJ but also different than all the other XS's as well, with it having the centrifugal timing advance built into the TCI but still using the vacuum advance, while the XJ does both electronically. The number for an 81 TCI would be 4R0 while the XJ uses a 10M TCI with all other years using the 2H7 TCI's. While the 4R0 and 10M TCI's are probably technically better units, they are so hard to find because of rarity that I'd be very temped to convert to 2H7 type ignition on an 81 at least (maybe not on an XJ because of the different side cover on the left side of the engine but almost for sure on an 81 if the original gave me even a slight hiccup, as the 2H7 is so much easier to service and easier to find a replacement unit if needed, and it's not like you have an advantage with the pickup coil wires like the XJ does since you still have the vacuum advance yanking the pickup coil wires around and breaking them.

[Chadwic82]

Really don't want to go through all that to make it run. Just trying to get it together to sell. Bought it as a project to get into road bikes but ended up losing intrest. Is there a way to check the pick up?

[Chadwic82]

It has a 4RO-10

HEY! Welcome Chad. Always glad to see another Okie.

Phil is right, sounds like a pickup wire. That's a pretty common problem.

If you still think it might be the TCI I might have one here. I'll need the #s because I think they used 2 different ones in 81 depending on the date of manufacture.

I think the late 81s had the same ignition as the XJ. Not sure of that though.

Got several 2H7 boxes laying around.

Holler if you need help. I ain't far away.

[TopCatGr58]

Hey Chad,

Let's back up a bit. We need some more symptoms to work with. You say you're trying to get it running. What are you seeing when you try to start it? Any hint of it trying to catch/start, or just motor cranking and cranking?

Have you pulled the spark plug from either 1 and 2 or 3 and 4, and then layed them on the head/engine with the spark plug wire still connected, and turned the engine over and checked for presence of SPARK on the plugs? IF no spark, but motor turning over, you stated you were seeing only 11 volts at the orange/gray wires. Those wires are just the trigger wires for the igntion high tension coils, and the voltages will fluctuate as the TCI switches the current off/on during the rotation of the engine.

You need to test the voltage at the BATTERY during cranking, and if it's dropping near 11 volts or less, then as stated by Nate, the TCI will NOT work with too little voltage and will not properly trigger the ignition coils, etc, and the bike/engine will not run. If the battery voltage is LOW, a quick test is to just put a jumper set from a car battery on it(car engine OFF for safety sake), and then try starting it. If it then catches/starts, you know it's the battery being too low...or/as well as lots of dirty corroded connections in the wiring also as stated above ie the frame/grounds, and will need a good cleaning.

These bikes are fun and reliable once they are setup properly. IF you haven't actually ridden it yet, get it running, and then take it for a short test ride, you may change your mind after that!?

T.C.

[oldyam80sg]

T.C.is correct-these bikes are reliable when everything is set-up right.Back in the 80's these and several other Japanese bikes were called UJM (universal Japanese motorcycles).Put in oil,gas and go.Very little maintenance was required for them to run.I think when my carbs were synced correctly back in 1988, nothing went wrong for years.I put fresh plugs in every other season and checked the oil,maybe put on some new tires and rode.I think when i was in the National Guard and my unit was activated and sent to Germany only during that time did my bike sit,but was started just not ridden.Batteries do go bad-My Kawasaki battery lasted 8 years before i had to replace it.My Wal-Mart battery last 2 years before it died.Just have some patience and before you know it you will be riding! Good luck!

[Chadwic82]

It will crank and crank and then backfire after a bit. I know its getting fuel becaise the plugs are wet. Installed new plugs and tested all of them against the cyl. head. Had spark on cyl. 1 and 4. 2 and 3 had nothing. Swapped the wires feeding the coils and 2 and 3 worked but 1 and 4 had nothing. So then I ohmed the wires going back to the tci for continuity and all tested fine. After searching online for a solution I came across Randy Rago's site. Thats where I read about testing the orange and grey wires in which he stated that when the starter is engaged the voltage should fluctuate irratically which the wire feeding the coil for 1 and 4 did. The wire feeding the coil for 2 and 3 dropped to 8 volts and stayed there until I let off the starter then went back to 12v. However, tonight I checked the voltage at the battery while I hit the starter and it went to 10.56 v so I'm going to stick it on the charger tonight and try again in the morning.

[Douglas Money]

Sounds like a bad pickup coil wire.

[Chadwic82]

which ones are those?