1980 400 starting issues

[amoyer]

I have a 1980 XS400 that I am trying to getting running. When I bought the bike a year ago it ran and it ran lean since the previous owner converted it to a single carb. I have replaced the bad spark plugs (checked and they were grounded out), I checked the coils they seem to be good, I just cleaned out the carb which was actually clean from sitting for a year with very little gas in them. I still can not get it to kick over, it is a kick only bike. The previous owner did chop up the wiring harness and did their own electrical (it was a barn find and not sure of the completeness before him.) Any other thoughts on what it could be? Let me know if there is anything else you might need to help me figure it out.

Thanks

 

[levdir]

Easiest thing first: what kind of shape is the battery in? Even kick only XS400s need a battery unless they've been converted to a permanent magnet alternator.

Have you tested the new sparks? Get a friend to hold them against the head while you kick it, see if you have spark. If you've got spark on both cylinders, verify that you're getting fuel. Even if the carb is clean, these BS34s often need two or three cleanings to fully flush the small circuits out.

What kind of shape are your carb boots in? If you're getting fuel but you're already lean, cracked carb boots will just make it worse. If the single carb manifold is metal mated straight to the head then you can rule that out, obviously. Couldn't hurt to check the gaskets anyway though. What kind of filter are you using? The cheap Emgo cone filters don't really work super well with our carbs. If you're just test-firing in a closed garage try pulling the filter to ensure direct airflow to the carb. Don't actually ride it that way, obviously.

 

[amoyer]

It is a brand new battery.

If I get spark at each plug, how do I tell if I am getting gas to the motor? I have gas in the bowl of the carb. Just not sure of a way to test that gas is traveling to the motor. The filter is an oval filter not sure the brand as there are no markings. I have tried with no filter and it installed nothing changed. I will check on the gaskets when I get home. Could points be a problem or oil level?

I have the service manual that is on here but I didn't see any troubleshooting for this issue or anything like this on here.

 

[levdir]

1980 should be TCI, and if you're on points and you're getting spark on both cylinders and they ought to be gapped correctly. You can tell if there's gas flowing by kicking a few times and then pulling the plugs. If they're wet, there's gas in the chambers. Don't test the sparks if they're wet, if they're working you could start a fire. If you've got gas on the plugs and spark Is the choke working correctly?

 

[amoyer]

The TCI is a black plastic box, right? What is the size roughly? This is my first bike, so forgive some stupidity. I attached 2 pictures I had of my bike. Any idea on where the TCI could be located? Could it be under the tank?

When I had the carb apart the choke lever moved a rod over/opened the hole inside the carb. I would think that means the choke is working.

 

[levdir]

The oblong black box, roughly 4x5", is the ignition controller, but the TCI pickup is under the little cover on the head on the left side of the engine. Your bike is definitely TCI, anyway, points bike have little vanes on the pickup cover. The ignition unit is probably in the electronics box under the seat, there wouldn't be room under the tank. The coils eat up most of that room. The other thing you could try is futzing with your idle screw. With those chopped headers and single carb, you're going to be extremely lean, which can make for hard starting. I uh, don't remember whether tighter is richer or looser, but play with it. You'll probably need to readjust after you get it started and running but if it get it started that's progress.

Do you happen to know if whoever did the single-carb conversion got it running at some point?

 

[amoyer]

I wasn't able to get to trying any of the items yet. I was able to take some things apart while I had light and took some pictures. I found the TCI module. But I have a few others I am not sure what they could be. The bike was running as it is. I had the previous owner start it up to show me it ran. I just didn't start for a year once I got it. Now that I have the time I am trying to get it to run. I will try messing with the idle screw.

So here is what I am guessing is the TCI it has just been gutted and fit in the make shift electronics box.

I have no idea what the Gray box is. Any thoughts?

Also not sure what the black boxes are in the background.

Here is the TCI pickup. I guess this looks normal?

 

[BBS360]

Interesting custom electronics....
That is the tci board.
The grey box is an automotive voltage regulator. A couple members have done something similar and there is a writeup somewhere if you want to understand what was done. That piece above the fuse box is a custom rectifier too.
I'd be a little concerned about heat building up with everything in a closed box. Many people swap out the glass tube fuses for more reliable automotive blade fuses. Otherwise looks all right.

 

[amoyer]

I tried kicking it over and then pulled the plugs out they are dry. So it seems I am not getting fuel. Does this mean the carb needs to get cleaned again? There is still fuel in the bowl.

 

[Sesty]

when in doubt clean the carbs carb. you only have one makes it twice as easy. if you no longer have the vacuum petcock i would assume you need to cap off the brass barb on the intake boot.

interested to see this running on one carb