pickup coils

How do i test the resistance on the pickup coils? just between black and (other color) wires will show the resistance? I see the manual says around 700 ohms.

 

tested at 584 and 610.

 

I don't know the specs on the pick-ups, but the way I've always done it is a shade tree/ redneck test.
Take note of which coil is firing. and pull all four plugs. ground them and attach the spark plug wires. Don't mix them up though, one coil works the inside cylinders, and the other coil works the outside. When you know the two plugs that are firing, switch the coil wires (gray and orange) That's the feed from the IC. If the same set of coils fire after the switch, then you probably have a bad coil. If the problem follows the wire, you've narrowed it down to the IC or the pick- up coils. Put the wires back where they are supposed to go.
The next check I do, is to use the same procedure, but with the wires coming out of the side of the engine that go to the pick ups. Again switch the gray and orange wires (you'll need to either pull the wires from the harness plug-in and connect them, or use some jumper wire). Again, If the problem follows the wire, it's a bad pick-up coil. If the problem still exists on that coil it's probably the ignitor box.

It may be redneck, but it usually takes me about fifteen minutes, and narrows the part down pretty quick.
*note: of course this may be a little harsh on the coils, and you don't want fuel involved with open spark.*
Can I make a short story longer, or what?

 

Manual says 700 Ohms +/- 20% (at 68F). Gives a range of 560 to 840. You're in spec.

 

Your specs are good. You should be measuring between the Orange and Black and the Brown and Grey. Be sure to disconnect the connector (sorry if this is insulting, some folks don't know better) before making the measurement. The schematic shows the Black and the Brown wires are tied to each other so you could test everything from either one. Sounds like your in good shape and EatAtJoes flowchart will narrow down the options in a jiffy.

 

Yeh I see I'm in spec, thanks guys. @eatatjoz, I have *NO* spark, and I'm trying to see why. I am in the middle of a rewire after total disassembly, and am just trying to get running again. I have everything wired to specs according to this diagram and I am getting no spark. pickup coils test good, ignition coils test OK, I'm beginning to think I have a bad ignitor. That's wierd, because the bike ran alright before I disassembled it, but wont run now. It's possible I farked the wiring in the early reassembly though. Anyone out there want to test my ignitor on your 82 xj650 Maxim for a couple dollars and return postage?

Here's an interesting note. Resistance through the secondary coil reads 11k without the caps, 20k (ish) with the caps on. Should there be ~5k per cap resistance in the caps? They are new and unused NGK caps from the dealer, and my stock caps read nearly the same. Weird.


***EDIT***

Per the electrical diagram I am using, I see no *BROWN* wire on the ignitor at all. Black and orange paired and black and grey paired, one set of each going to the pickup coil, a red/white along with the orange/grey going to the ignition coils, and ablack/white going to a relay. Below is the wiring diagram i am using. #14 is the ignitor, 15 is pickup coil. They are located bottom right(ish) Sorry for the img size.

 

Yup, spark plug caps have resistance, Yamaha specs say
5.0k ohms for #1 and #4
10k ohms for #2 and #3

 

Wow buddy, that is one big image! I am using the Haynes manual, your schematic looks like a Clymers set up. I am surprised to see there is a difference, but I will offer up that the Haynes shows a specific schematic for the H, J and so on rather than a cobbled together one-size-fits-all schizmo. There is a significant change in the J as compared to the H, what with the starter interlock system and all. They do appear to be exactly the same otherwise but the interlock system is rooted into a lot of the systems that would cause your issue. I think you should kick this schematic to the curb and get either the factory book or the Haynes. This one is just too generic and I've had nothing but trouble trying to fix stuff with these generic schmatics. It is possible that one could mistakenly wire up the switch with such general terms. I'd offer my schmatic but I'm fresh out of scanners. Perhaps Nick could hook you up. I'd offer to check your TCI against mine but I cannot dynamicaly test it at this time. You should be able to test it on any of the 650s from 81 through 84. Hit up a buddy with an XJ. You may also want to check out this link http://www.jetav8r.com/Vision/TCIRebuil ... build.html
and or this link
http://www.xz550.net/tci_english.htm#a12p0 (appologies if this link is dead, I can't verify it at this time).
Best of luck to you on this one and, should worst come to worst, send me the harness and the TCI and I'll check it out for you.

 

On component #14 (TCI box) you'll see two sets of wires. One set coming from the pick-ups, and the other going to the coils. On the plug that comes from the pick up coils there is a black/white wire.
Unplug that wire and see if you get spark.

 

GOOD CALL! Sidestand safety cutoff will kill spark. The wire eatatjoz suggests you disconnect grounds the signal to the TCI when the sidestand is down unless the transmission is in neutral, preventing spark.

If the test eatatjoz suggests gives you spark try reconnecting the wire and pulling the sidestand relay (it is up under the tank just behind the rear of the valve cover). If you don't have spark the black/white wire is grounded somwhere. If you still get spark check the neutral switch.

Also, you didn't get the sidestand relay and the starting circuit safety relay switched did you? I think they will plug into each others sockets. Looks to me like switching them would also kill spark.

 

I might add, there are no safety relays in the circuit. The PO removed the clutch switch and sidestand switch. Should I see voltage on the black/white wire?

I have deduced that every testable component in the ignition system is to specs per the Haynes manuel. Leaving the ignitor as the last questionable component, which I suspected as faulty.

 

If there are no relays, your PO must have hacked the harness to jumper the interlock system. I'm not too savy on the interlock system (haven't had to futz with one yet) but the schematic in the Haynes manual shows that the black/white wire it the input to the TCI from the sidestand relay. I'm betting there should be 12VDC there. Another relay you might want to check would be the starting circuit cut-off relay. It is tied to the clutch and neutral switch and, near as I can see, would cause a no-spark condition.

 

Starting circuit cut off relay prevents cranking the engine.

The black/white wire may not show any voltage with a meter. It's purpose is to ground the signal coming from the pickup coils, so would show tranisient signals when engine is turning.

If all the safety relays are gone, then this wire is serving no purpose. Go ahead and disconnect it. If it still doesn't spark then think about the TCI.

 

^what he said !

If that wire gets grounded it kills the spark. You can check it by putting the positive lead from your multimeter on the battery and the negative on that wire. If you get 12 volts then your safety system is grounded and the bike won't start.
If that wire isn't grounded, and you still don't get fire, double check that you're getting 12volts to the red/wht wire on the coils, and to the red/wht wire going to the other plug on the TCI box. If you do have power, and that blk/wht wire is ungrounded, go back to Robert's link and start looking for cold solder joints on the TCI board.

 

Gentlemen...

I appreciate all of your help. After exhausting all of my patience with this problem, I decided to buy a new ignitor and hope that's the problem. I found one pretty easily on ebay and it should be here early next week. That being said, I decided "what the hell" and popped (read=pry) open the ignitor. Here's a couple horrible out of focus photos of what I found.



I don't know if it's Yamaha procedure to put Werthers Originals in there and let them melt all over everything through the years, but that's what it looks like. I'm guessing I have found my problem???

 

I think that stuff is supposed to keep the components from vibrating loose. I had that goo on mine too, and some kind of clear-red epoxy on the back of it.
Since you have it out, look at the back of it, and see if there are any loose connections. If you can get it going again, it's always nice to have a back up.
And good luck with the new one.

 

I photoshopped a quick diagram of how my bike is wired. The lighting is all independent of the ignition/starting system, so I didnt bother including it. Also, as you see the starter is independent of the ignition system too, so no safety relays/sidestand switches etc. I have left the black/white disconnecetd as some of you have mentioned. Now here's the $100 question. Given all components are in proper working order, should this bike have spark at the plugs when I'm pushing the start button? Ignition coils and pickup are to specs. The only thing not tested is the ignitor.

 

Don't rightly know, pics are all fuzzy. Hope you have found your solution in a new unit.

 

I posted this rough drawing a few months ago and it may or may not help.
http://www.xjbikes.com/uploads/forums/i ... rcuit1.jpg

I don't have that many wires to the ignitor on my seca 750, but everything looks square. I honestly don't remember what I did to eliminate all of those wires, but I can tell you it took a lot of Fosters and miller lite.

Maybe you just need some beer, and it will come to you in a EURIKA!

 

I assure you, the beer quota has been met while working on this bike.

 

Well, from the schizmo you whipped up, you look good. With the correct resistances on the primary and secondary windings on the coil, you should see a spark. It looks like you have narrowed it down to the TCI rather well. I would hope that you are able to clean up your TCI (alcohol or good electrical contact cleaner should do fine) and reflow the solder contacts. Of course I would suggest doing this after you get your Flea-bay unit and get the machine running again but you may as well go for it. You have very little to loose. Good work, sounds like you earned that beer quota.

 

New igniter arrived today. I plugged it in and it sparked better and brighter than the old one ever did. Thanks guys for all the help, I'm back in the game! Back to FORWARD progress!

 

Don't chuck the old ignitor box!! It may still be useable. Did you get the chance to look at the solder runs?