82 XJ400 Ignition trouble

[Ivan]

Trying to help a guy at work diagnose ignition trouble on an XJ400. I have never laid eyes on the bike. I am running blind here.

What are common troubles with them to check?

Any place I could find a pin out diagram of the TCI module?

TIA
Ivan

[Jerry]

This has come up a couple times. I had an '82 XJ400 Maxim that would not run when I got it. I "carefully" removed the TCI cover and re-soldered all the connections of the edge pin connector. (Removed the old solder with solder wick.) From the feedback I've seen, these units were prone to developing a bad connection on the edge connector, which is where the wiring from the bike connects to the TCI. Flexing with heat / cold / vibration seems to cause one or more of the solder joints to fail. I put over 45K on that bike after the repair, only sold it when I was moving between states and couldn't take it with me. Let me know if you want to part with it.

The TCI itself is very reliable other than the edge pin solder issue. I would try re-soldering before trying any board-level repairs. I do not know if it is the same tci used on earlier 400s; the '82 has the YICS system (as well as a monoshock rear suspension using the same size rear tire as the later XS / XJ11s) and other major differences from the early 400s. I suspect the TCI is unique to the '82.

[Ivan]

Well, the bike was delivered to my garage last weekend.

I have found that it isn't a spark problem, rather the engine is not getting fuel. It will run on carb cleaner, but not on its own.

Checked the bowl drains, and it had fuel in the bowls, so needles can't be stuck which was verified when I took the bowls off.

What I did find that looks rather suspicious is this:



Looks like the hole which the screwdriver is pointing at is missing an aluminum plug. It goes straight to the venturi, so I am thinking it is equalixing the pressure in the venturi and bowl, and not allowing the mainjet to pick up any fuel.

I just want to make sure this hole is NOT supposed to be open.