Xj550 won't run

I have a Yamaha XJ 550 motor and I can't get it to run. The motor will start but it will not run it is only firing on cylinders one and four. I'm hoping someone knows what I can do to get it firing on the other cylinders. I have confirmed that both coils are good as I can use either with the outside cylinders. The problem is that I'm not getting any spark to 2 and 3. There is continuity from the gray wire on tci output to the coil. Have any suggestions to get the bike running?

 

Swap the coils. See if 2 and 3 spark then get the valves in spec and compression test each cylinder.

Gary H.
I answered this on my break. I should've read more carefully.

 

Try swapping the plugs out of 1 and 4 into 2 and 3. It sounds to me like a case of the inner plugs being faulty.

 

Do what k-moe said then unscrew the ht caps, cut 1/4" off each wire then replace the caps. One of the the caps has a screw in resistor. Make sure it's snug. Hope this helps.

Gary H.

 

All of the plugs are new. I just don't seem to have the current to the coil for 2 and 3. That is a gray wire coming from the tci. Whichever coil is hooked up to the orange wire works, but the gray doesn't. Is there a way to test the tci?

 

Before messing with the TCI, check for continuity on the gray wire.

 

After verifying continuity on the coil gray wire, checking out the pick-up coil resistance would be a good idea. Do you have a service manual to give you the specification and procedure? Along with the specified resistance, make sure they don't go to ground either. Member SQLGuy did quite a good job on troubleshooting no spark and a great explanation on the wasted spark system. You can find that here:

http://www.xjbikes.com/forums/threads/how-to-ignition-troubleshooting.21932/

 

I checked and do have continuity from the tci to the coil on the gray wire. I will check the pickup coil after work tomorrow. I would like to know if anyone does know a way to verify if tci is good.

 

The only TCI test that can be done at home is swapping for a nown good TCI, or swapping the suspect one into a running bike. All other tests require test equipment. You might try an electronics repair shop for that.

 

There are three main problems that TCI units succumb to after years of reliable service:

1) bad solder joints on some of the internal components (known as "cold solder joints") result in the component pieces coming loose from the circuit board, and thus they can no longer perform their function reliably (or at all).

2) component failure......a blow-up transistor, a burned circuit trace, etc. This situation can develop if you have a short-circuit in your electrical system, or hook up your battery or jumper cables incorrectly, etc. TCI units do not like "big blue sparks" in the electrical system (except at the spark plugs, of course!).

3) another common failure of these units occurs if the TCI is continuously grounding the ignition coil (i.e. its output driver is shorted). You can verify this situation with an ohmmeter with the following tests:

- disconnect the 2-pin plug at the ignition coil and measure from the orange or grey wire to the chassis. You should see very high resistance. This should be pretty close on both the working and non-working channels.

- if you read a few ohms of resistance or less, then the TCI is bad. A shorted driver will also make the ignition coil run very hot and may ruin the coil.

4) dirty external terminal connections.


Bad solder joints can be repaired by someone who is skilled at that sort of diagnosis and repair, and even individual circuit components can be replaced, but it's tough to find someone in the modern world of "pitch-and-plug" skill-sets who actually has the skill and patience to do this type of work. Yamaha gave absolutely "zero" electrical specifications for checking the condition of the TCI units, besides the afore-mentioned "check everything else first" type of diagnosis.

But you can perform a simple set of tests to determine whether your TCI unit is good or not, without having a second, known good unit to install in place of the suspect unit. Although these instructions were written for XS owners, the exact same thoughts apply to the TCI units on the XJ-series of bikes:

http://www.xs11.com/forum/showthread.php?t=38224&highlight=tci+repair

The above is stolen, borrowed or even plagiarized from Randy Rado's site before it went away. It does require an analog meter as digital multi-meters do not show the swing of the needle that is required to test it.

"Using a voltmeter set on 12VDC, connect the positive meter lead to the Orange or Grey 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 both Orange and Grey coil leads."

All of the XJ-series TCI units are of the "4RO" style as described in the above article.

Video here:

http://s307.beta.photobucket.com/us...4.html?&_suid=1354140627504033601775276167517


And if the above isn't enough, if you feel the need to get medieval with your TCI unit, well, then it doesn't get much better than this:

http://www.jetav8r.com/Vision/IgnitionFAQ.html


By the way, the TCI needs a minimum of about 10VDC to operate………and while the starter will spin the engine over like mad with low voltage, the TCI falls on its face at less than 10 volts…which can lead to all sorts of confusion when a battery low-voltage condition occurs!.

 

As k-moe suggested the best way to verify a TCI is to swap it out with a known good one. And, as Len posted those are some excellent steps to check for shorted output transistors or defective solder joints internal to the TCI.

However, in your case you have at least one good channel as plugs 1 and 4 are sparking. Therefore, you could also do as SQL Guy suggested and swap the wires as in steps 5a ( http://www.xjbikes.com/forums/threads/how-to-ignition-troubleshooting.21932/ ) to see if the sparking pair of plugs changes to isolate a defective channel in the TCI.

I would start with doing the continuity checks on the pick-up coils and the steps Len suggested as that could identify the problem and you could avoid trying to swap wires on the main harness TCI mating connector.

The 550 pick-up coils should be 650 ohms +/-20%, measured between the Orange and Black for 1 and 4 pick-up coil, and Gray and Black for the 2 and 3 pick-up coil on the larger of the two TCI mating connectors. None of the wires should ohm to ground.

 

So I've tested and believe that the TCI is bad. The gray wire seems to be shorted to ground within the TCI. I also tried the analog meter test but couldn't tell if it was what I wanted or not. Any ideas where I can get a TCI for a reasonable price? Well the TCI off of a set 650 or 750 fit this bike? Thanks for your help.

 

There are several on ebay (you have to search for xj550 cdi). This was the least expensive working one (at least they clam it is) Check to make sure it is the same one that you have.
http://www.ebay.com/itm/CDI-ignitor...-83-/121623045296?hash=item1c514c64b0&vxp=mtr