XS1100 vs. XJ1100 ignition

Are any of you familiar with the XS1100 ignition system? The Achilles heel of that bike is the flexing wires in the mechanical advance. Does the XJ1100 retain this system, or did they come up with a better way by then?

I’m wondering what is the best approach to a reliable old bike.
1) Retain the stock system entirely.
2) Switch to aftermarket ignition.
3) Is the XJ1100 ignition a reliable alternative?

 

I'm using an XJ1100 ignition system on my XS1100.
The XJ set up bolts straight on to the XS without any modification except for using the XJ ignition rotor.
It works a treat and like you said does away with the flexing wires which are the Achilles heel of the XS.
I've had 3 XS1100's which i converted to the XJ system but each time i've used the later style carbs so can't comment on how the system works with the standard early XS1100 carbs.
Almost forgot, each time i've done the mod i've always lost the neutral light, though i 've connected it. Don't know why, maybe something to do with the XJ igniter box and the XS clocks. Mind you, if you're like me and have been around bikes long enough, you get the feel for where neutral is, it sort of floats when you get there if you get my drift.

 

I assume the XJ retains the vacuum advance? Is the XJ TCI box plug n’ play?

 

Yes, the vacuum advance is programmed into the XJ igniter box. I'm pretty sure it's plug and play. I'll go and take some photos.

 

I believe I read that FJ1200 carburetors are a direct swap and mate to the air box. Their disadvantage is no vacuum tap. Now, I’ll have to do further research on that as well.

 

Yes, FJ1200, FJ1100, XJR1200 and early 13's, some Suzuki and Kawasaki too. Lots of info over on the UK XS1100 Club forum.

 

I could not have asked for a better response. Thank you!

 

Sorry i forgot about this bit of your query.
All you have to do is run the fuel tap, or petcock as you call it, in the PRI or PRIME position. I switch mine to OFF when not in use. It has the advantage, or disadvantage, of overflowing when the float needles are shot, which could mean fuel in the crankcases if not careful to shut off.

 

I'm interested/curious about this swap..........the XJ1100 models use an electrical pressure switch (transducer) to convert intake vacuum to an electrical signal that is fed into the TCI. It's a small rectangular plastic box with a vac nipple (port) mounted up top between the top frame tubes (mounted just in front of the regulator/rectifier unit). The vac port goes to a brass nipple (port) on the #2 carb body, but I think that it could also be hooked to the intake manifold with teh same results (?).

The XS1100 models use a vac can on the pickups (that seems to be mechanically controlled?)........where does this vac can get its signal from?

FJ111200, when you did this swap did you use that XJ1100 pressure sensor box? And if so, where did you plumb the vac line to? (intake manifold?).

Finally, just looking at the parts diagram, it seems as though there are a LOT of various gadgets and mechanics associated with the XS1100 system that are not present on the XJ1100 system..........do all those fiddly bits get removed and the pick-ups baseplate and reluctor wheel just bolt straight onto the XS1100 engine case and crankshaft? Everything lines up perfectly?

Neutral light: Both the XJ and XS1100 models use the same neutral switch, but the XJ models also use a neutral switch relay (which the XS1100 models do not)........but it may be the harness for the p/u coils carry that light blue wire on the XS1100 models, where as the XJ1100 models locate it elsewhere?

 

The vacuum advance on the XS1100 works off of a port on the #2 carburetor. It is connected directly to the vacuum advance mechanism. (There is also mechanical advance)

 

I've only used the boost sensor once, and that's on this Midnight Special i'm running at the moment. The other two times i just ran the bike without it. Seems to work fine either with or without. I've hooked it to the vacuum take off port on the carb body and followed the wires into the TCI.
Yes, just take off everything that's associated with the XS1100 and just use the XJ1100 items, everything lines up perfectly. The vac advance from the XS1100 is not used.
Honestly i've tried to get the neutral light but it just keeps eluding me, maybe i'm not doing it right, but i can live without it.
I think that's about it, i might have forgot something and come back later.

 

Fat bloke starting my XS1100.
XS1100 using XJ1100 ignition system if it's any use to you Marty. Bike fired up from stone cold. Some alterations to the carbs, mainly the jet needle used is from a standard XS1100 on the top clip position. Main jet 137.5. I had never seen such a balls up of a set of carbs by the previous owner. He told me it ran much better than when he first got it, god knows what that was like.
Anyway, don't laugh, it's my very first attempt.

 

Thanks. It looks like a viable option to consider.