Follyworks

you've got 4 fuses in an old xs400 - one for the Main, and then fuses for Ignition, for Signals, and for the Headlight. So if you have a dead fuse, and anything at all works, it's not the Main. If it starts and has working signals, the fuses for the ignition and signals are fine. So that mangled and missing fuse in the fuse block is likely the reason why the headlight doesn't come on. Replacing fuse holders is easy enough - I replaced my entire fuse box with new blade style fuses after I had some of the fuse holders snap as I was changing fuses.

Sometimes the forum is a little slow to respond. I've got a '78 xs400, been tweaking it out for a bit now. Biggest problem mine seems to have is with the ignition system. The old points systems keeps slipping out of adjustment, and when it does, it's a bear to start - that and making sure your carbs are clean are your most likely culprits on the hard start. A common problem on the old xs400 is a revving problem - once it's warmed up, the idle speed will climb to around 3500 rpm. If you get happenning on your bike, hunt around here, how to fix it's been covered a few times.

I replaced the coils on my '78 xs400 with ones from MikesXS, a site which heavily caters to XS650's, but many of the parts swap to other XS models. So at $24.00 for each of the 2 coils, my '78 xs400 is running great, and the 78 xs400 and a 77 xs360 have the same OEM reference number for their coils.

sounds like it's already giving you feedback as to what it needs - it needs that right cylinder firing! If it's firing intermittantly, and when you tested you got no spark on that side, it's likely an electrical issue with the ignition system giving you an issue now. Check the coils and the points - a '78 is old enough it's still using points instead of electronic ignition, and they can be a bit fiddly at best.

the peak in the background there is Hawksbill Mountain, and is about 4000 ft in elevation. Looking a differnt direction from the same overlook, I could see the valley below, at something like 1200 ft in elevation. The ground drops off fast in some of those places.

Having finally gotten my bike all tuned and running well, I decided it needed to be put to the test - 4 days of riding in and around Shenandoah National Park in the Appalachian mountains. The main road through the park is over a hundred mile long, windy and hilly, surrounded by trees, wildlife, and occasional breathtaking views, snaking along high ridges the whole length of the park. I have to say that the bike handled it all pretty well - these were roads where light and maneuverable are an asset, though camping gear strapped to her made it a bit more unwieldy then usual. Fortunately, I packed light. Averaged just shy of 60 mpg, and had no real mechanical issues. Out for some day hikes, and stopping to enjoy the view. The saddlebags are modified military surplus bags, on a custom built bag mount (having welding tools and the skills to use them comes in handy sometimes!) Loaded for travel. sleeping bag made for a decent backrest, and my tent-ish gear is tiny, so the load is minimal. I came back with tons of photos, though few of them include the bike, a sunburn on the back of my neck, from between the bottom of the helmet and top of my jacket collar, and a fresh appreciation for the plan of always bringing rain gear, no matter what the weather forecast says.

I just reiwred most of the fusebox on my '78 xs400e. In mine - RED (from battery) - to MAIN RED (going up the headlight) - from MAIN The 3 browns - all are power going in to one of the other 3 fuses. All have power when the bike is turned on with the key, and I think you could swap them around (i.e. it doesn't matter which they go to). I think, if I remember correctly, that the Red/Yellow goes to the ignition fuse, and one of the red/white wires goes to the headlight fuse, and the other red/white to the signals - however, they all use 10 amp fuses, at least in my bike, so if you've got some switched you can test easily by seeing what works. Put simply - pair one of the brown wires with one of the striped red wires. No browns go to browns, and no striped go to striped.

Well to start, if you've switched it from the original air filters to Pods, you will need to likely change out the jets. The Pods give more air flow, so the fuel mixture need adjusted accordingly. But as a seperate suggestion, start your own thread here on the forums - you're more likely to get answers for your bike instead of things about the OP's bike, and get urged to tell us all about your "new to you" bike.

what part of the wire "Came apart"? Did it come loose from the coil, break somewhere in the middle, or come free of the spark plug cap? If it's from the coil or a break in the middle, it's as Jim said (though my '78 xs400 didn't have the wasted spark coils but still had the wire moulded in). If it's just loose from the spark plug cap, that's a pretty easy fix, and can be found at most suppliers of parts.

On mine, I took the seat off, and carefully peeled the old seat cover off, duct tape and all. Then I sliced it apart to make a pattern to make a new cover out of fresh vinyl from the upholstery fabric store. Only 2 seams to sew and it went back on easily. Of course, this method requires ability to sew, or least finding someone else who can. Though if I were buying a new one, I'd probably look at JP Whitney.

While I can't say whether it will or won't work (I've looked at the system myself, I can comment on some of Jim's points. The PAMCO electronic ignition isn't a full and complete system like the factory installed systems they add later - it's a system that replaces the points. Just the points are replaced, so the bike's existing ARU unit stays put. In theory, the the advance unit in your bike, and it's mechanical effect on the ignition curve, stays the same. But with the switched side, you get position problems, as well as maybe having the shaft spinning the wrong way. So may or may not work. The electronic unit replaces the plate that the points are mounted on - so Jim's comments about mounting positions is likely dead-on. If the slots and screws aren't in the right places, there's no way you can mount it right, especially since you'd need adjustment room it to get the timing right. All that said, it seems like a useful mod to replace finicky old points systems - let us know what you work out! For those unfamilair with this particular unit, here's a link - Pamco electronic ignition - to the maker's site.

Old bulbs and an impact from dropping it could do it. But if you dropped the bike on it's left side and lost the left turn signals, I'd guess some wire got pinched, pulled, or otherwise mangled. Might not be damaged at the fixture itself, but possibly where the fixture mounts to the bike. As far as I know, the front and rear are wired such that if one bulb goes out, front or back, the other should still work. But you've got a loose wire somewhere in the connections, that might not be the case.

I'd replaced the coils on my '78 xs400 just a few months ago - used ones from Mikes XS650 site, the Part #17-6805, about halfway down the page, and seemed like a good fit - similar stats to original, fit the original mounts, and the bike runs great with them in. If you think it might just be in a wire and want to keep the coils but replace the leads to the plugs, you might have a problem - the original coils have the lead wire as part of the unit, epoxied in place (replacements, the wire is seperate), and the only way to replace it is to cut it and splice a new one on. There's a lot of voltage there, so you'd need to track down some kind of fitting to do that splice properly.

It's an old enough bike to have a points ignition system - so check things like the points gap, dwell angle, and the timing. The points ignition is very high on the list of "Reasons why this old bike doesn't start well", but at least is easier to fix then taking the carbs apart again.

And there is a thin gasket between the cover and the body, to keep moisture out. If the cover hasn't been taken off in a while, that could be holding it on like glue - a light whack ought to free it up if that's the case.