No spark?

[lunut87]

After a 15year down time, I have tried to revive a long lost Yamaha. The only problem is I have no spark. I am in the process of cleaning the connectors, since there all green and dirty, but if that doesn't work, is there any common parts that may go bad from sitting to cause a no spark issue?

[randy]

lunut87;

You've got a good start with cleaning the connectors. You didn't mention the model? On the XS11, there are connectors behind the fuse panel also, so don't miss them. Also, the spark plug caps should be unscrewed from the leads, cut 1/4" off the wire, screw them back on. The ignition coil connectors are under the fuel tank.

Make sure you have a fresh battery, then see what you get.

[Ken Talbot]

Connectors is a good place to start. Pay attention to the ground connection points too, where the negative battery lead connects to the frame, and the ground strap that connects the engine to the frame.

While you're in the fuse box, take each fuse out (carefully), and pull on the metal end caps to ensure they have not broken free and/or corroded inside the cap.

Lastly, you'll porbably have to do some work on the pick-up coil wires. There's an article in the tech section here .

[lunut87]

Oh sorry about that, its a 1979 XS1100F. I typed up an introduction thread just seconds before posting this and forgot that I hadn't mentioned the model in this thread.

I do have a brand new battery in the bike, and I have actually completely replaced the fuse panel. I was checking the fuses and getting ready to clean up the connectors on the original panel and the brass fuse holders were so brittle they just broke, a few broke as I was taking fuses out. I replaced the fuse block with a similar style of glass tube type fuse block from Advance Auto for $5. It uses a 1 1/4" long fuse instead of the 1" fuse but there's more then enough room for it under the cover without modification.

I was careful to remove only one wire at a time and place it on the new panel one at a time and in order, just to be sure I didn't mix any up.

[lunut87]

Well I have some more information and a question or two.

I went through the bike last night with a multi meter and found some things that kind of threw me off.

First, I have the correct OHM readings one both inductive pickups at the connector under the fuse panel, I wiggled the wires and they are not broken.

Next I have power to the coils, I think I have 12v at the double plug for both coils.

I have power at the ignition module at the rear of the bike and I have power from there to the coils.

I have cleaned the bolts that mount the coils, the edges of the brass grommets in the coils and the edges of the tubes that the coils mount to on the frame to ensure a good ground on the coils, but looking at the wiring diagram I think that it was all for nothing, but I could be wrong. I have also cleaned all the connectors I could find on the bike and repaired the mouse eaten wires.

I have 19ohms resistance on both of the coils, is this in spec? The actual spec was 15ohms.

The question I have is with the ignition module unplugged, I still have 12V on both signal wires to the coils. Not on the box but in the actual connector. Is this a grounding circuit that fires the coils or is it supposed to energize to fire? Would bad coils cause the signal wires to have constant power?

[egsols]

I believe the TCI only switches the ground to the coils. 19k ohms is a little high, I think the specs were 15k +/-20% at 68f or 12-18k ohms.

You might want to check you pick coil wires before anything else. Check out the TECH tips sections, there's some good threads about coils and pick up coil wire repairs.

[randy]

lunut87;

i haven't read through all of the posts above, but i assume we're discussing the 1100 and not the 650?

On the 1100 the tci grounds the coils, so YES, there should be 12v on the red/white at the coils. i believe it's the same system on the 650, but i'm not certain.

BTW, the 12v should be fed to the coils through a ballast resistor, cutting the 12v down to (IIRC) 9-10V.

[3Phase]

Originally posted by lunut87
The question I have is with the ignition module unplugged, I still have 12V on both signal wires to the coils. Not on the box but in the actual connector. Is this a grounding circuit that fires the coils or is it supposed to energize to fire? Would bad coils cause the signal wires to have constant power?

Hi, Lunut, welcome to the forum!

No Spark? Check the grounds.

The engine-->frame ground is the large Black cable attached to the left side of the engine and the frame near the side cover lock.

The system and TCI grounds are the Black wires attached to the Regulator/Rectifier under the gas tank.

With the ignition on you can perform a very basic test for spark by using a spare spark plug in one of the spark plug wires and disconnecting the ignition coil negative wires and grounding them to the frame to see if you get any spark.


The TCI uses a grounded circuit similar to old-style points but it uses transistors instead of mechanical breaker points.

Except during engine cranking, the 12 Volt supply for the ignition coils does not come from the TCI, it comes from the ignition switch to the fuse box, up to the right handlebar kill switch and back down through the ballast resistor to the positive side of the ignition coils. During engine cranking the TCI supplies 12 Volts directly to the coils, bypassing the ballast resistor.

Good hunting!


Regards,

Scott

[lunut87]

I was thinking it was a grounding issue last night when I was looking at it. I couldn't get the rectifier screws out, at least without the right tool, since I think they're a little rust welded in. Now that I know where the engine ground is I will check that as well.

Thanks again. I'll let you know how it goes.

[lunut87]

I checked everything. I have continuity between all ground wires to the frame. I checked the ignition and all wires are still connected and look fine. Coils were tested by grounding them manually and they fired.

So the only thing left would be the TCI unit. I found the testing procedure for the unit on here and I will test that tonight hopefully.

I will see if I can fix it myself, but is there anyone that can rebuild these units if need-be. Otherwise I will be looking for one that works. If anyone has one I will be looking to make a deal here once I confirm that's what i need.

Thanks for the help everyone.

[randy]

is there anyone that can rebuild these units

You're lookin at him! Do the tests on my webpage (www above), then if you still have problems, you can send the tci to me.

[lunut87]

thank you.

I found a used one that my dad had lying around the house from a bike that he bought that was in a wreck for parts, years ago.

I plugged her in tonight and wammo she fires right up. sounds great. blew a mouse nest out of the exhaust system which was hilarious.

Now all I need to do is sync carbs, change tires, bleed the old fluid out of the brakes, and change all the oils and its on the road.

Thank you for all fo your help.

I am thinking I may want to have that TCI unit rebuilt for a spare. I want to have a look at it myself and see if its just something a simply soldering iron can fix, but if not I am interested in having it done.

[Shappers]

Glad you got it sorted out..

Randy,

Do you ever end up with any units that can't be revived? The reason is, I'm after a 4R0 box that I could put my own electronics into, it would simplify the wiring a great deal!

I never see broken ones come up for sale on ebay and I don't want to pay out for a working one..