Xj650 coil wiring, help needed

Hi all,
I have an xj650 chop project on the go. When I got it it was in boxes, it now together, minus the wiring.

Having just looked at the wires labelled “coils” I’m wondering how to determine which of them go to which coil, and how to determine which ht lead will go to which spark plug (they are all the same length, I’d hoped they weren’t to give me a slight clue, but no)

Wiring was always going to be my stumbling block, so any help or advice would be greatly appreciated

Thanks in advance
Mark

 

The red wires with white trace, are (positive feeds) I am sure. One goes to each coil and the grey and orange ones are the same from the pick up coils on the end of the crankshaft to the TCI and then from the TCI to the ignition coils. Do you have a wiring diagram? As it is a waste spark system in that when for example cylinder one is on compression four is on exhaust the ignition will happen on both cylinders. I don't think it matters which coil grey and orange go to but if I am wrong those more knowledgable about the 650 will let us know. Hope this helps?

 

Thank you so much for your reply, franz. I don’t have a diagram. But with the state of this loom, I’m sure I wouldn’t need 70% of it haha.

I think this has helped a lot! Thanks!

 

My XJ wiring was a disaster when I got the bike, but I eventually got it sorted out. Fitted a replacement loom and spent ages cleaning up electrical connections and checking for continuity and voltage drop. I am no auto electrician but part of the magic of being a biker is sorting the bikes too. You will get it sorted.

 

there's a "minimum wiring diagram" around here somewhere, it might be easier to just make your own loom. it might sound hard but it's not too bad

 

Sometimes it is better to do that Polock and it is something I would like to do for one of my bikes. I need to understand more regarding the gauge of wire to use etc. And info on this?

 

The 1, 4 coil can be identified by the shorter plug caps, the 2, 3 coil has the longer plug caps.

Normally, the 1,4 coil mounts on the left side of the bike, and the 2, 3 coil mounts on the right side of the bike.

Color matters with the Orange and Grey from the TCI, not with the R/W that supply 12V to the coil.

The Orange works with coil 1, 4, and the Grey works with coil 2, 3.

Note the main engine harness ground (eyelet / ring terminal) is normally attached with the coil mounting hardware.

 

bigger is better
in general the wire has to carry more current than the fuse, there's charts for that.
i think #16 will do most of the bike, with #14 for the higher current things, alternator, headlight, maybe ignition.
some things could take smaller than 16 but then your buying more kinds of wire, i don't think that's economical
i'll get flack for this but you only really need one color wire. put it on double check it, test it and it will never move by itself, it looks cool too

 

Yeah....just get a really big roll of BLACK

 

The machines I used to maintain and repair all had one color of wire for the cabinet harness.
Every wire did have a code inked on it to identify the circuits though.
Big fun when the ink faded to being illegible.

 

Thanks for all the help dudes!
I’m super confident now
Need to check my valve clearances and get the rocker cover back on. Then it’s spark time

 

One last thing... are we saying cylinders are 1 to 4 from left to right, as we are sat on top of the bike looking down? Haha

 

My bike would not start and one of the people on the forum advised me to check the clearances. I had to change four shims and afterwards it started all the time. The previous owner said the bike had been serviced and there were a few things wrong which indicated otherwise, which were sorted. Better doing everything, carburettors cleaned and balanced, valves, electrics, it will be well worth the work involved to get your bike reliable. I was surprised as I was used to the locknut type adjusters on my CB750K2. The shims are easy to change with the right tools.

 

Yes number one cylinder is at the pickup coil side of the engine.

 

Are you an electrical engineer k-moe?

 

Yeah carbs all cleaned out. The slides were all stuck open, but freed up easy enough, no real dirt or grit in the carb at all. Had a mild panic when I dropped the brash washer that sits under the main jet. Literally took everything out of the garage to find it again haha.
I really hope the shims are fine, wouldn’t mind starting it tonight and I don’t have any replacement shins. And I’m away for a week from tomorrow and il just be wishing I was in my garage tinkering hah

 

Great M4k3y one other point is that another reason my bike would not start was blocked jets in the float bowls. On the XJ 900f these allow fuel to go the brass tube into the engine side of the carburettor for cold starting, I assume it will be the same on the XJ650. I put on eye protection and sprayed carb cleaner through the bowl jets just to make sure it flowed through. Anyway you have probably done this but I mention it just in case you don't know about it as it will make your bike difficult to start.

 

Yeah man, I gave it all a good going over when I had the carbs off. I’m assuming you mean the real slim brass jet, this was the hardest to clean like, but I got a small nylon bristle down there, and when I’d blasted the carb cleaner off/out I put my gob round it and could get air through each one of them

 

Yes thats it I didn't know about them the first time I stripped the carbs lol.

 

Nah. Just an ex-machine tech.

 

1982 XJ650: is this an acceptable setup: Dynatek Dyna Coil 3.0 ohm, 30k Volts, 1k ohm wires and BPR7ES resistive plugs?