Bike won't start. need electrical help!

[YamaRule]

I have a 79 xs1100 special and I was wondering if anyone could help me out with a couple TCI (2H7) questions.
Bike won't start. I checked my pickups and they were both about 750 ohms. All my wires I tested on my Tci showed the appropriate 11.xx volts and one 6 volt. Heres where my question lies. when I try to start it, my voltage on the orange or grey wire drop to around 8 volts and I know it takes alot more just to fire the coils. The ballast resister has been bypassed. BTW I have Mikes Green coils and 7mm wires on it. When I use a testlight and crank the engine, the orange wire will flicker my testlight, the gray wire stays lit, but dims slightly. any ideas?

[natemoen]

Start pulling connectors apart and cleaning them. You have resistance somewhere in the wires or connectors.

[cywelchjr]

What is the voltage at the battery while cranking. If it's not staying up above 11 volts then the battery either needs charging or replacement.

Make sure that the battery is good before going further. If you want to check it out before that, you can jump it from your car. Some claim that you will destroy the electrical of the bike if the car is running, and the charging systems on SOME bikes can be damaged doing that, but not these. However, some auto charging systems don't like having another charging system pushing back at them, so it is safest overall if your being cautious to not have the car running. I can say I haven't found a need to have the car running in this type of case.

There is one caution, if the battery on the bike is low rather than just bad, the charging system of a car CAN charge it faster than is good for the battery, it won't blow up, but could overheat and boil the electrolyte.

[YamaRule]

Update:

I don't think it's my battery because on occasion it actually starts, but only runs for 20 to 30 seconds and I have to work the throttle to keep it that long. no fire in 2 and 3. pipes stay cold while 1 and 4 get hot. I cleaned all my connectors and re-soldered my TCI. Nothing seems to be working. I also did my pickup wires a month ago. the only thing I can think of is the TCI is bad. Does this seem right or am I in looking in the wrong place?

[Rasputin]

I would still suspect the battery may be a problem. These bikes do not charge enough until the rpm's are up a bit. Just use battery from another vehicle or boost the bike to see if it makes any difference. If it does, it proves what was wrong, if it makes no difference, you know one more thing in your search for the problem. At the very least it does eliminate the possibility and is simple as well as quick to try.

[YamaRule]

Update:

I just tried boosting it and got nothing. tested the battery while cranking without a boost and it never dropped below 10.8 volts. The only thing I'm down to as far as I can tell, is the TCI. is there any way to replace a bad part inside the tci or is there something else I should check first?

[Rasputin]

I copied this off of Randy' page because he explains it nicely.
"Using a voltmeter set on 12VDC, connect the positive meter lead to the Orange coil lead at the TCI. Connect the negative meter lead to the black (negative) lead at the TCI. Turn on the ignition. Voltage should come right up to about 10 - 11VDC. Crank the ignition and observe the meter. Look for a wide voltage swing during cranking. A strong swing indicates that the pickups and TCI are working OK and your trouble is between the TCI and the plugs. Possibly a bad ballast resistor, bad coil, bad plug cap or just corroded connections. Repeat this test for the Grey coil lead."
You have to have the old style sweeping needle type tester to do this as the newer digital ones will not show the swing he talks about. If that checks out then the TCI is good and you will have to look further.

[YamaRule]

Update:

I'll find a meter to use, mines digital. so correct me if I'm wrong. If one of my coil wires coming from the TCI drops in voltage but doesn't swing the needle, it's eithor my TCI or pickups. Where my pickups are both reading around 750 ohms even with me moving the wires around. My problem would have to be my TCI wouldn't it?

[b.walker5]

Randy's test is okay, but it's not the only way. Your digital meter will do fine for the basic checks that will rule the TCI out, or in.

If you havent got one, click this link to a post by member Catatonic Bug and find the link to the service manuals in his signature file at the bottom of the post. http://www.xs11.com/forum/showpost.p...2&postcount=13 . Download both Clymer and the Factory Manual. Look up page 6-11 (section 6, page 11) in the factory manual and it will show you the votage tests that you can make with your digital meter. The Clymer manual is almost useless for this info but it's handy to have for other stuff.

From your description it does sound like the TCI, but I wouldnt rule out other things just yet. A loose earth (ground) and high resistances at other connectors can play havoc with things like this, so thoroughly, and systematically rule everything else out first.