Help if you can, or trip is cancelled...

[psycoreefer]

5 volts at the coils is way to little, should be around 12, same with the TCI around 12 even when cranking. ON a full battery you should read 12+ at the coils and at the TCI.

What does your battery read while cranking?

Try swapping the battery from the "good" bike to the "bad" one, A battery can hold voltage but still be bad, that is why they have "load" testers....

Time to start cleaning connections....

[DGXSER]

Or time for a new battery. Heck, if you swapped carbs and TCI, swapping the battery shouldbe cakewalk. Try it and eliminate the next item. "calulatus eliminatus is the best friend that you got! The way to find that missing something is to find out where it's not!"

[CA]

Just got back from SC riding in the back of a prius. I wasn't a happy camper watching all the bikes go by. o well.

So before I left I switched to a brand new battery and it helped nothing.

So it either has to be very poor electrical connections or timing. I am getting spark so I find that it could only be poor electrical connections to a certain extant in my mind.

Two questions:

1.Which/Where are the connections I need to clean? Particularly those that would affect starting i.e. the coils.

2. Is it possible to adjust timing when the bike isn't starting? Productively at least?

Thanks

[DGXSER]

You certainly can check to see if the timing is close enough or not. Pull the no 1 spark plug out and put a screw driver or something like that in the cylinder through the plug hole.

Now, turn the engine over by hand. watch the screw driver as it rises up, when it stops rising, see what the timing pointer is pointing at and note or mark it. Then begin turning the engine some more very slowly, when the screw driver just starts to drop, take note again of where the pointer is at. Half way between the two points, should be the T mark (or F depending on the year of the bike IIRC).

That will tell you if your timing is correct. At least close enough it should start and run.

[Ivan]

If he is getting 5V at the coils while cranking I would say that might just be has multimeter averaging the voltage while it is being switched by the TCI.

If he has spark, fuel, compression, and time, it should run. I don't think the ignition timing can be adjusted far enough out to cause a no start.

If you blew the carbs out of the holders, your spark is way out of time. The fuel air mix is being ignited while the intake valve is open. This is either going to end up being the cams out of time, or the plug wires in the wrong positions. It could also be the pickup coils reversed, which I encountered when switching from a 2H7 to a 4R0 ignition and back. The two TCIs have the pickup coils wired opposite, which puts the spark 180 out of time.

Have you had the timing pointer off the crank shaft? It may be possible to get that installed without the peen in the crankshaft not lining up with the slot in the timing pointer.

Have you pulled the valve cover to check cam timing yet?

[CA]

No I haven't taken the valve cover off. I thought the compression would have shown a problem there. But it may be prudent if I find I have timing in line as well.

Your right though about blowing the carbs out, but that was when I had switched the leads to the coils. So that is actually what should have happened from what you were saying.

The thing that really gets me is that this problem must have come and gone, since it began doing it right up till replaced my coils. Afterwhich it ran for about a week then began exhibiting the same problem. Now it won't start. Before I thought it was the coils.

I guess after verifying crude time I will pull the valve cover. See if its still lined up.

Could it be electrical if I am getting spark? Any such thing as too weak of a spark that wouldn't ignite the mixture. I always thought spark was spark.

[DGXSER]

In my experience, it would be very unusual for the spark to be to weak to at least start the bike and run it. It might be to weak to give enough power to ride, but typically not to run. In fact, I had a Honda Civic many years ago. It would start and run, but much more than a tap on the gas pedal and it would stumble and stall. I drove home fifteen miles at about ten-fifteen miles an hour, never even shifting out of first gear. Wound up being a bad coil.

IF you have proven all the components of the electrical system as in pickup coils, TCI, coils, Plug caps, and plugs, then it almost has to be a loose connector, sirty connector or a bad wire.

Still, after cranking, check the plugs to see if they are wet, REALLY wet, or dry.

[RUSH]

Have you confirmed that the fuel is flowing from the tank? I have found that if it's an electrical problem it's either runs or it doesn't. Pickup coils go out, dead. Bad connection in the wiring loom, dead. You state that it got progressively worse then died. All your checks have shown that there is still spark at the plugs. You've swapped the carbs, battery, tci. I am curious about the possibility of fuel not making it to the carbs. I dont know if this would explain the backfiring through the carbs though? That sounds like timing. Have you checked the firing order?
This is a puzzler. When my pickup coils went out it was a lot of cranking followed by one big backfire/explosion. I had noticed that it was missing every so often in the days leading up.

[randy]

+1 on what has been written, timing is about the only variable left. Since you've got compression, valve timing is OK, so ignition timing is the last piece of the puzzle.

Follow DGxser's advice of rocking the #1 piston to find TDC. When you get it, you should have the 'T' mark lined up with the timing pointer. While it's there, look through the hole in the timing plate and you should see the rotor lined up with the pickup coil. Top one or bottom one I don't recall, but one of them. There is a mark on the pickup also.At the 'T', the marks should be very close or a bit retarded (ATDC) . That's because the engine actually fires at the 'F" mark, 5 or 10 degrees BTDC, depending on which model or even which manual you've got

It's possible that the timing advance plate and/or the rotor advance mechanism is stuck in the advanced position. If both of them are stuck that way. It won't start

[CA]

ok so TDC lines up very closely to the naked eye and the screwdriver.

when it is at the T mark though I cannot find any alignment with the back plate. I see a hole in the bacl plate yet it does not line up with any holes on the timing plate. If the front timing plate is on T then the rear hole is at about the 55 degree mark. Not sure if that is what you were talking about randy.

on a side note, when I first dropped the screwdrivier in I began turning and it immediately jammed the flathead against the cylinder I had to reverse it just a tad to release it. Hope I didn't hurt anything!!

[randy]

You're looking for the timing rotor to line up with the pickup coil, NOT the back plate. Remember, the rotor hits a pickup every 180 degress, so look at the lower one also, you may see the rotor tip there. Either one will do.

No, I don't think you ruined anything by catching the screwdriver.

[RS Thornton]

vacuum line

Kind of left field but looks like you have gone through almost everything else.

Have you checked that the vacuum line from #2 to advance on left side of bike is good? If this is leaking the timing is mechanically correct but operationally wrong and you can get hard/no starting and backfiring like you described.

[XS1100 Newbie]

You can also hook up your multimeter on the DC voltage scale, and see when the coils fire in relation to the timing. I am just not sure which wires on the bikes you would use. Having spark is good, but having spark at the right time makes things run.

[CA]

no that's a good suggestion, I checked the vacuum line by sucking on it and it moved the ignition calipers just fine.

randy I now see what you are saying and yes the top one does line up. It's just a little bit ahead but I suspect that's fine.

so I was going through the basics again and tried to start it...no luck. So I pulled the number one spark plug to check for spark and when I hit the starter the bike almost came to life. It started then backfired and stopped. When it began starting I noticed the 1 plug started really firing but afterwards I could barely get a spark out of it.

I am going to put the battery back on the charger and come back and expirement this afternoon. I find it odd that it does better with number 1 plug out and grounded to the head....

maybe it's a dumb observation but I am getting desperate!!

[randy]

You can also hook up your multimeter on the DC voltage scale, and see when the coils fire in relation to the timing. I am just not sure which wires on the bikes you would use. Having spark is good, but having spark at the right time makes things run.

Good idea, but i don't think a meter would react fast enough.

Now, a TIMING LIGHT would be the ticket! DUH-UH I'm surprised none of us suggested that yet