Its been a while since I had my fairing off so I had to search for some info. I found this thread:
https://fjowners.com/index.php?topic=20000.msg204629#msg204629My mistake. Looks like it runs to a separate vacuum advance box, not the ignition box.
Be sure you are looking at ignition boxes from the same generation (84-87 vs 88-95) because there are 2 flavors of oem FJ ignition boxes
1) TCI (transistor controlled ignition) uses a dual pick up coils which were installed on the USA 84-87 FJ’s
The TCI boxes have a built in vacuum advance module. See exception below.***
2) DCI (digital controlled ignition) uses a single pick up coil which were installed on the USA ‘88 to 95 FJ’s
The DCI boxes used a remote vacuum advance module (better design, easily replaceable) therefore, there is no vacuum port on the DCI box. You can not mix these 2 different systems together. You can not use the DCI box (no built in vacuum advance) on a early FJ and a TCI box on latter FJ’s.
Mine has a vacuum pipe coming from the opposite end to the connections, another 1tx that I have broken for spares has an ignition unit without, what’s going on here then?
Again, be sure you are not comparing a DCI (no port) to a TCI box (with port).
Apples and oranges systems.
***Here’s an exception: Not all FJ’s with TCI came with vacuum advance. It’s been reported by our FJ brothers in Australia that their FJ’s do not have this vacuum advance feature. Early TCI boxes in Aussie land do not have a vacuum port on the TCI box. All USA bikes do have the vacuum advance.
If you *are sure* you have Ignition boxes from the same 1TX model, perhaps you have a USA box with a vacuum port and your other box is an Australian box without a vacuum port?
What does the vacuum advance do?
*The vacuum advance has nothing to do with performance*
It is a emissions control feature. It advances the timing when you close the throttle to burn off unburned hydrocarbons. Your FJ will run just fine without this vacuum advance as I can attest along with our mates from the land down under.
If you want to bypass the vacuum advance, no worries, just be sure you cap off the vacuum port on the intake manifold. Use the heavy oem Yamaha vacuum caps down there, it gets plenty hot on the engine side of the heat shield. Thin wall vacuum caps are not appropriate.
Aftermarket Ignitions (Dyna, etc.) do not have any vacuum advance features.
Here you can read more about the vacuum advance:
http://www.fjowners.com/index.php?topic=11690.0Cheers. Pat
Either way, if you don't have a vacuum line running from your intake to under the fairing then it may have been disconnected. My understanding is all FJ1200s had the advance, maybe they didn't in Poland?
Edit: I just saw your other thread where you mentioned you relocated the ignition box. I'm guessing the vacuum advance box is right next to the ignition box from the factory. So you likely would have removed or relocated it if it were there.