Almost there - A question

[randy]

patrick,

I agree with Ken that your problem sounds like an electrical one. Are your engine and battery grounds clean and tight? and you might consider doing the 'solder fix' on your TCI box.

[prometheus578]

"Doing too many things at once..."

when writing, to save time, I often leave out little details.. minor things, really, but sometimes not.
Is it possable, that after you synch'ed things, you still dicked around a little... and that you have the pick-up wires, or the wires to the coils crossed?
Not that "I've" ever done that,(yeah, right!) but... cranking and cranking and then the backfire(provided that everything else is correct), sounds like #1 and #4 are firing when #2 and #3 should be getting the spark.


"That Synch'ing Feeling": With the idle down low(Which I actually don't advise...) when you're synching the right and left banks, you can actually adjust the #3 carb screw to the point where NO butterflies are open. Turn the idle speed screw in a little (As in raising the idle) and see if it starts now.

[Incubus]

I agree, Pro, it sounds like I've got the timing 180 off. I've done that. A few years back I had to rebuild the engine in a Mercedes 230C my son had (paid two grand for it. He drove it three weeks before overheating it and blowing the head gasket. Eight miles on the brand new tires at the time). When I got it together I couldn't get it to start. Same thing, crank, crank crank, backfire. In that case I finally discovered I had the timing chain on 180 degrees off. I switched the two and three plug wires and vroom - on the road again.

I didn't think it was possible to time these engines 180 off. Now, when I had it running after the synch and timing I never did put it in gear. Theoretically, I suppose the engine could have been running backward. Bizarre theory, I know, but I am tending toward the bizarre right now. I don't know how to check the static timing in this bike short of pulling the valve cover, and I haven't gotten that desperate yet.

I'm thinking of switching my coil leads from the TCI to see what happens.

I also have another TCI. I think I'll plug that in and see what happens....

Patrick

[skids]

I hope that you haven't switched brain boxes between the 81 and the older models without other mods. I tried that once and got big back fires!

[Incubus]

OK, switched the TCI out. No change. Switched the coils leads. Still backfires.

This is all leading me back to the only place I messed with the spark, which of course is the advancer unit. I never disconnected the coil leads nor did I remove the entire wire harness when I soldered the new wires to the pickup coils. The timing plate only goes on one way, right? Could I have turned it 180 when I put it back on? Wold it have run at all if I had? When I timed it with the timing plate reversed would it not have stopped dead?

One thing I have discovered in my years of hobbying on old engines. I have discovered ways to do things wrong that were never envisioned by the engineers who designed these things or even contemplated by the science of physics. It's a wonder I haven't accidentally altered time and space.

Or maybe I have, but since time and space were altered I was also altered and so I am completely unaware of the changes. Yeah, that's it. My engine does run, just not in this time continuum.

It might be easier to change the time continuum than fix this spark....

Metaphysically yours....

[skids]

I'll bet that you mixed up the pick-up wires when you soldered new wires in there. If so, the easiest fix is to swap connectors at the main coils. Been there, done that.

[John]

When you had the advancer plate off did you by any chance remove the governor assembly? That would be the centrifical advance mechanism, the one with the counterwieghts that sits on the end of the crank. It can be installed 180 out if you're not careful.

[Incubus]

Seventy-five minutes.

That's how long it now takes me to pull the carbs, bench synch them, check the float height, pull the jets and examine them for any blockage, reinstall the jets and carbs and put the air filter back on.

I have done this task way too often. Hopefully that's the last time this year.

The synch was not great, according to my homemade gauge (small plastic zip tie, hit the end with a hammer, makes a nice thin graduated surface). The bike idled very well before it went into its coma. I don't know how. My gauges are surely past their useful life. Can a bad synch keep a bike from running? Tune in tomorrow and I'll have an answer for you. I would do it tonight, but if I don't try I'll go to bed tonight knowing - just knowing - that my bike is going to roar to life tomorrow. Sleep will be easier that way.

I also went back and put electrical tape over the solder on the new wires to the advancer. I used only shrink wrap the first time. I have convinced myself that the lines were arcing through the shrink wrap. We'll see. Andreas may be getting an email from me tomorrow if the bike still won't run.

I'm originally from Wisconsin, so the next time I start a thread like this one, I'll have to remember to serve cheese with the whine.

Patrick

[Incubus]

So can someone tell me how the pickup coils on my XS11 work?

Latest update. After pulling and resetting the carbs last night, I went out today to try to start it. Crank, crank, crank and nothing. Not even a backfire. The plugs are wet now, so they are getting fuel, but there is something they are not getting.

With apologies to B.B.: The spark is gone. The spark has gone away.

I put tape around the solder on the new wires I installed on the pickup coils last night and now somehow I have killed the ability of my bike to manufacture fire. While my bike is infinitely safer this way, it is heaps less fun.

One interesting note: when I was trying to use my test light to see if there was any juice coming off the pickups to the TCI (which I don't even know is possible), the spark returned as long as the test light was grounded and touching the pickup wire.

I don't know about the advisability of riding the bike while poking a test light into a wire harness by my ankle. Shifting, at least, might prove troublesome. On its face it doesn't appear to be a bright thing to do.

Not that I haven't done things that were even more astonishing stupid than that. Someday I'll tell you the story about the two bottles of Mad Dog and the 110 cliff into the quarry in Butler Wisconsin. About half way down I was instantly sober. To this day I wonder if I died that day and just don't know it. Or that other time.... never mind, you get the picture.

So, can anyone tell me how electrical tape around those little pickup wires could possibly have killed the spark? Or where the pickup coils ground without a test light attached?

I have juice to the TCI, I have juice to the coils. I have brand new spark plug caps and plugs.

And I am lost on a sea on a sea of confusion.

Patrick

[randy]

Wow, this is a new one.

OK, the pickups work like this. As the reluctor ( attached to the crank) spins past the pickup coil it induces a very small voltage in the wires that lead to the TCI. The TCI amplifies that voltage to turn off the coils. It's that simple.

My theory is that your solder connections are no good. You're not getting a strong enough signal from the pickups.

You wrote that you added wire. What type of wire? Did you use rosin core solder? Before you soldered, did you remove the silky threads from the wires? You may have noticed that the original wires are stranded with strengthening thread woven in between the strands. The threads must be removed in order to get a good solder connection.

Lastly, check the reluctor gap ( between the reluctor tip and the pickups) the gap should be .7mm. Any larger gap and the pickups will not produce a strong signal.

Oh, and to repeat, have you done the solder fix?

[John]

Randy, those are the very same symptoms that I had with the 78 TCI before you repaired it.
Patrick, do you have a spare TCI that is known to be good? If not I have some spares, I could send you one, or maybe webbcraft could help you out.

[Ken Talbot]

There you go, you've pretty much confirmed your porblem is pick-up coil wires. It is interesting to read, but the actual operation of the coils has nothing to do with your problem. When you put the tape on, you dislodged and broke one or more of your fixes, or dislodged another break that you hadn't found and fixed yet. Go back to the repair procedure and start looking again for weak spots where the wire pulls apart when you pull vigorously on it. Be sure to uncrimp the retainer just before the wires leave the housing. This is a very common place to have a break, and it can be difficult to find if you don't loosen the crimp.

You're going to like it once you get this fixed!

[Incubus]

Looks like I'm got some resoldering to do....

To answer the queries thus far:

Randy, I used pieces of wire from the leads from an old multimeter, as the tech tips suggested. I used solder from Autozone, which was I told was the right stuff for an electrical connection. I will be more careful this time about silky wires.

John, I have another TCI, which I was told is good but have never actually run. I have been back and forth between the two TCIs with no discernable difference. I have, however, the shiniest electrical connections ever recorded between the pickup coils and the coils. The bike did run, however, before began fixing it.

And Ken, when the bike ran Saturday, during those stretches when it wasn't missing, it was breathtaking. As I was flying down the road, hanging on for dear life, I wondered what I was going to do to keep my other bikes happy. When my XS is running properly, they will be getting a lot of down time. I have an 18-year-old son waiting anxiously for my Honda 750.

It is fortunate I love working on my old bikes. I end up doing a lot more of it than more proficient folks....

Patrick

[Incubus]

New wires, new solder.

Vroom.

Thanks, guys. She's running rough, like one of the wires isn't perfect or maybe just because she's stone cold, but she runs.

Started with a big backfire, which I attribute to residual gas in the cylinders, but she started right up and she idles. I'd take her out for a ride, but the fairing is off and the lights go with it.

Now I can start fine tuning her all over again.

Patrick