Differences between the XS and XJ

[nightpilot]

I just got an 82 xj1100 with a factory fairing which I am reconditioning. I see that mine has yics and wonder what other changes were made going from the XS to the XJ. From the sounds of some of your mileage experiences, I am hoping for a drive gear change. Does anyone have some enlightenment to share?

[wingnut]

The engine is pretty much the same except for the YCS. Thats a bore that runs thru the head to balance the airflow between the cylinders. You will need to make or buy a tool to plug it off while you sync the carbs. As far as a finial drive, you can do the XS750 mod to drop the RPMs about 500 at cruise. There are detailed instructions on how to do this on the forum. Search 750 MOD. Oh and welcome to XS land

[nightpilot]

Thanks for intel wingnut. good quote. I have a 81 parts bike that appears to be an xj re the yics. Is there a way from serial number to tell if it is a 650, 750 or what it is, i also seem to have a rear drive from a 700xj, would that work in the rear drive?? I tried to view the link noted by TC but my computer would not let me see it.

[petejw]

also the ignition set up is different,
the TCI is different
the 81xs has vac advance the xj doesnt.
i think there are other electrical differences but dnt own 1 and
cant think of anything else other than the yics already mentioned.

[wingnut]

If you think its an XJ check out the XJbikes.com site. There is a thread there that will tell you what you need to know using the serial number of the machine. Here's a link http://www.xjbikes.com/Forums/viewtopic/t=14561.html