XS 400 help please, new rider!

[fredintoon]

i actually just replaced the battery... maybe it is? if so what do i do? do i need to re-grease the chain?

Hi Kieren,
Chains must be continually nurtured.
Cheapskates lube chains with used engine oil but that flings off too quick.
Traditionalists melt the spare chain out of the can of Linklyfe and swap it for the chain on the bike but you can't buy Linklyfe these days.
You should go to a bike shop and buy a spraycan of chain lube.
It don't matter which one, despite what the cans say, they all work well.
Put the bike on it's centrestand so the rear wheel can spin freely and fizz the entire chain with the lube.
Re-lube the chain every second or third time you fill the gas tank.
Eventually the chain will wear and need replacing.
Replace the chain and both sprockets as a set.
Old sprockets eat new chain and old chain eats new sprockets.
Replaced as a set they go on together like an old married couple.

[petejw]

what Fred said about the chain. :-)

regarding your battery, if its overcharging it could
cause the battery to spit out acid, have you connected
the breather hose to the battery? if so check on its routing,

[brcree]

xs 400

Ok Smithman...I have a 81 xs 400 myself, tryen to get it back up to snuff so to speak. I'm haven the same prob with the high idle when I shift myself. Still tryen to figure that out. Will let you know if I fix that. Looking at your pics......your 1# spark plug wire looks like its toast. Change both of them. The white stuff looks like chain grease...the spray kind. Look at all your elect. connections. Pull them apart and clean, clean, clean. I use denatured alcohol and a q tip. Whats goen on with your fuel line????? Get you some clear line and get rid of what ever that piece is inline. Make sure when you take the carbs off that you make sure the carb boots between the heads and carbs are snugged up, with no cracks. I've gotten many parts off of E-Bay....just type in xs400 and 1200 or so parts will show up. Check out the ground cable where it is connected to the frame.....clean that down to metal. I hope this will get ya goen....need any more help just ask, I don't know everything about this bike but it's very similar to my 81 xs 1100.

[brcree]

xs 400

Just took a closer look at your pics.... there is a problem with the butterfly valve shaft end seals drying out and leaking , this can cause strange things to happen while idling. By looking at the side shots of your carbs it looks as if that might be a culprit with the stained look on the carb. body.

[yozzie]

I had this same bike and same high idle problem. Back out the idle mixture screws a bit at a time to provide extra fuel at idle. These bikes do not like to run lean at idle, makes the idle hang.
It would be good to check the idle mixture screws for the o rings that should be on them. If one or both are missing it will run lean as well causing the idle to hang.

[scooter123]

Sorry to thread jack...im new to the site and cant find where to start a new post.. and I hope someone can help me

I have a 78 xs 400 and I just finished a tear down and cleaning of the carbs and I just noticed two little springs and ball bearings and I didnt see them fall out so I dont know where they go????????

[bikerphil]

They probably go on the choke lever mechanism.

[fredintoon]

Don't lose your balls!

Sorry to thread jack...im new to the site and cant find where to start a new post.. and I hope someone can help me
I have a 78 xs 400 and I just finished a tear down and cleaning of the carbs and I just noticed two little springs and ball bearings and I didnt see them fall out so I dont know where they go????????

Hi Scooter and welcome,
start a new post by opening the appropriate forum.
(you got that right)
At the very top on the left you will see a place marked "new thread"
Click on it and post away.
Like Phil says, if the XS400 carbs are similar to the XS11 carbs there's a rod linking the carbs that pulls across to fully or partially engage what is properly called the enrichening circuit but hey, call it a choke like everyone else does.
The little springs, followed by the balls, go down crossdrilled holes where the rod slides through.
You gotta put them in first and hold the balls down with a small screwdriver to slide the rod across on assembly.
The balls click into detents on the rod to latch it in place when you pull the "choke" knob out.

[scooter123]

Thanks fred!!!

[brcree]

*1 xs 400

Hay Ksmith....I have a 81 xs 400 special and had the same prob with it revving up high when I shifted.......look at this stuff..........main jet size, air/fuel needles need to have 1. small spring 2. small and i mean small metal washer 3. small and i mean small rubber oring, in that order. Turn these needles in until they bottom out, don't over tighten!!!!!!! Tips will break off and its a soab! to get them out!!!!!!!! The book says to turn them back out 1 1/2 turns. Also look at the side of the carbs and you will see the flat end of the butterfly shaft.......there is a c clip, remove......a felt washer, remove...and a small rubber oring...replace if dry and brittle. Air gets sucked in here if oring is bad. Do a good carb cync after all this is taken care of. Make sure your carb boots are tight against the cyl head. My left carb stayed wet with fuel until I took the petcock apart and found the oring in there bad, it had been leaking fuel onto carb for years before i got it.. Hope this helps man!