jordanscycles

its hard because you're pushing against the clutch springs when you push it in which is what it does when you pull the clutch lever. It can come out all the way with no problem and it'll go right back in with no problem, it looks fine, i'd leave it alone or if you did anything put a little wd-40 on it.. but it looks good.

not sure what you're talking about, but you should use hose clamps on each end of the tube to stop it from leaking if its from there. if theres a hole in the tube... replace it. or if you're talking about the breather tube coming out of the transmission, you've got a whole new set of problems none of which are attractive.

not to embarress, you but, you might want to check the Lights On Off switch on the right gauge cluster. If it's on turn it off and see what happens and vice versa, mighta been plugged in wrong when you changed the bulb or something. If that doesn't work, take the headlight out and make sure all the connections are good and the wires are in the plugs in the headlight far enough.

the fuel line will be closer to the front of the petcock, or the thing you turn to engage different fuel options. And the vaccum line is behind it, youll have to lift up the gas tank to see it, because its at the very back of the petcock. Also poor idle could mean clogged idle jets, I just put new ones in mine, which you might want to consider, they are like 4$.

You should check the valves, because I had that same problem and it ended up being that the exhaust valves were shimmed too much causing two of the four cylinders to not fire, but had spark and suction. You could rotate the engine to where the exhaust and intake should be closed and spray compressed air in to make sure it doesnt escape through the valve and valve seats.

Well I have a '78 XS 400 and I just went through the carburetors, getting all 4 new jets and soaking everything in carb cleaner, oiling the slide, needle valve, etc. Now it's easy to start, dont forget to use the tuning screws... And when I had the 3,500 problem after riding and pulling the clutch in, I fixed it by simply turning the idle down a bit, just a bit. Slowly unscrew the idle screw until it stops, should happen suddenly. But it'll be my first bike too, I think it's a good one.

Yeah it sounds like your pilot jet is blocked. Remove it with a small flat blade screw driver, then clear it with a jet tool, gently with wire, compressed air, you might be able to just blow it out. Also check the main jet for blockage, as well as your float level if you have that handy. Then again making sure your needle valve moves freely wouldn't be a bad idea eaither.

I'd like to know the intake and exhaust valve clearances if someone has them handy for a 78 xs 400. Also I can't tell what TDC is for both cylinders, because when I take off the points cap at the top of the left cylinder there is a mark on the thing that spins and the thing that doesnt next to it and when I line them up I dont know which cylinder is at TDC, and don't I need to put each one at TDC indivigually? Not sure how any help appriciated.

you can bypass the fuse box by taking the wires that would go to the ends of the fuse on the box and splicing them in to an inline fuse, which can be purchased at almost any electronics store. Or you could just get a brass brush, some WD-40 and some dielectric grease. Brush off the rust, then put the dielectric grease on the ends of the fuse where it is on the contacts, it'll prevent corrosion. good luck! Also found some online if you can't find any locally, ships in 24 hours they say. https://www.reddenmarine.com/site/item-deta...m?id=SDL4205531

nevermind. might try to sync them or the oil pump isnt fully working on the right side or something.

Just wondering if my 1978 xs 400 can be repacked, it has 3 pop rivots on the back of each muffler so I would think so, but I'd like to confirm before I drill them. Thanks in advance.

check the clutch plates, you'd be taking off the right side cover after draining the oil and taking the plates out after removing the keeper plate, if they stick together douse them in wd-40 and clean each one then put them back in and reassemble. If the plates stick together it will stop your clutch from disengaging because they have to seperate for it to do so. good luck!

That would suggest your idle jet(s) are clogged. It is a common occurance.

you can also turn the bike over several times and then remove the plug and see if its wet, and smell it, if it is wet and smells like gas then you're getting petrol my good sir

check the plugs for gas by kicking it over a few times and removing them, then if they have gas on them get new plugs because those ones are probably not firing hot enough. When you run it with the choke like you said earlier it fouls the plugs much faster.

fuses? check the contacts as well for the fuses. A bike so old should have dirty connections, so if you cleaned them up and put some dielectric grease on the ends of the fuse it should prevent further corrosion from building up.

Well I tore them apart yesterday and began cleaning everything with a toothbrush and some WD-40. I went to the local Yamaha shop and got brand new jets, about 3$ a piece. The inside of the carbs were pristine I must say, but someone put in bondo or something over the main air mixture screw hole inside the right side carb. So I scraped that off not even starting to wonder why they'd do that, put the jets in, new plugs, new fuel line, checked the petcock (worked perfectly). I assembled them slowly, taking my time to do it right. After all that, I turned the bike on pushed that beautiful button and it fired right up (after letting it be on prime till full then switching to on). I rode it around the neighborhood several times. The transmission is tight and feels very good. But yeah I picked this thing up for 450$ on craigslist from some guy that wouldn't spend any money or take the time to get it going. It really does look amazing, opening the seat and all the wires and the frame paint looks great. I cleaned it today and applied and reapplied aluminum polish (mothers) and it's going to need a few more buffings from that but I am very happy with this bike. I am 16 years old and this will be my first bike. My dad bought one of these brand new in 1980 and rode it for a few years till he got in an accident on it and sold it. By the way, we ordered the throttlebody off ebay and the card board is just precautionary because we are selling the house, it doesn't leak..

im going to get new stock jets.

So i picked up this bike yesterday from a guy that had it under a bike cover in his back yard for an unspecified amount of time. He said he could never get it to run for more than 10 minutes. I went through and oiled the slides, cleared the main jets even though they didn't really need it and put a few drops of wd-40 on the needle valves. The floats looked good but I did not check the level. So basically this bike will run on the first of the two choke settings, which is half choke. I was able to ride it like that last night and it ran ok. It sputtered and back fired when you let the throttle off, just as it does when its idling without load. But when I gave it gas it quickly picked back up. But I've never really rebuilt carbuerators, so I was wondering where to start with it. I heard of boiling them in lemon juice among other acidic liquids. Also when I opened the carbs up I noticed that there were the main jets that looked normal, but I couldn't see the idle jets, and there was like a screw that sealed them off it looked like, which I find crazy weird. And one other thing, the brass pieces the main jets screw into were loose and out of place. So I pushed them both back down, one of them clicked into place. Any tips would be appriciated.

I believe its the clutch adjuster.

I just went through the kick start shaft, and the last person didnt tension the spring before closing up. Works great, just kick started it and it fired, but it'll need that carb rebuild, I think that's next.

It's a 1978 xs 400 that I just bought off craigslist for 450$. Seemed too good to resist. Also my dad had bought one of these brand new in 1980. It's going to need the carbuerators rebuilt, and the kickstart was put on wrong by the last person. But it does start easily with the electric start and idles with no odd noises. Just thought I'd share.