Total Motorcycle Community Forums

Okay. I'm a newbie rider, and I just bought a used XS400 from a guy who didn't seem too technically inclined. He rode it into a garage one day, and then just stopped riding it for a year, then sold it to me.

I'm a poor college student, and thus, I'd like to make repairs myself, but I lack any kind of manual, and every step of the way, especially with regards to battery and gasoline, has been a hell of a learning curve.

First off, The fuel petcock seems to only have two prime settings and an On setting. Am I correct in assuming that I should leave it in "ON"?

Second - I bought new spark plugs on principle. Install tips?

Third - The battery was dead and beyond salvage. I bought a new one from Pep-Boys, the High Performance model for the bike. I filled it with acid and charged it with a wall charger til it had a complete charge, then replaced the old battery with this new one.

Heres a biggie: I attached the negative connection to the battery. As a test, I touched the positive cable to the battery, and the brakelight came on, and stayed on. This greatly disturbed me, because I assumed the bike was off. What is the proper procedure for installing a battery in a Yamaha XS400 Special??

Also, my ignition has no markings of any kind. At the moment, I have the ignition turned all the way to the left. i.e. I must insert the key, and the only direction it will turn is clockwise, because it is turned as far as possible counterclockwise. Is this correct? Help?

Finally, I hear that I need to clean my carbs, any good sources for step by step instructions?

Basically, I have no real instruction here, so please, if you can help me with any little bit of my problems, I'd be grateful. Basically, any information about the XS400 or general stuff about bikes relating to my problems would be a lifesaver.

Thanks!

-Bob

It's very possible that your key is in the 'Park' position, and that's why your tail light came on. Turn the key one click back and see if that works.

Spark plugs are pretty straight forward, if your really nervious about changeing them yourself, the best thing is to get a service manual for your bike. In fact get one anyway. It will walk you through most everything your likely to ever want.

Cause if it was just shut down and left for a year, you will probably need to do a little carb cleaning......

Changing the battery? Take the key out so you know it's off. Look at the dead battery. Everything bolted to the old one.... take that off. Swap batteries. Re-attach everything you took off the old one, saving the negative side for last. Make sure you connect the positive and negative to right posts on the new one... that's always a good idea.

Sweet. Okay, The key works this way: Theres all the way counterclockwise, then all the way clockwise. From either position, I seem to be able to take the key back out. theres a long smooth rotating distance before the key slows down and snugs into whichever side, and there are no "clicks" when I turn it.

As for the battery, I reattached neg side first, then touched the cable to the positive terminal, and things lit up. The battery was aligned properly, (i.e. pos & neg in their proper spots)

I'll take pictures of everything tommorow, and post it here.

I'm hopeful that theres some position between extreme right and left on the ignition that will make the lights go off.

Thanks for the prompt responses. I'll check this post again soon!

Cheers!

reddy,

I might be able to just send you a starter manual for the xs400, I purchased loose pages of of ebay taken out of the chilton manual. Bear in mind thougb that some of the pics are from the 83 xs400, which looks radically different from the 78-82 models.

PM me and in the meantime I'll hunt it down. In the meantime, good luck. I got a basket case xs400 running too last summer, so it shouldnt be too big a deal.

K

That would be fantastic. Thanks a lot Kar!

I took another look today, and I talked to a few friends. We noticed that it was only the brake light that was lighting up. Is it possible for the brake light to be on when the rest of the bike is not? Solving the electrical problem so I can finish connecting the battery might solve a bunch of other problems.

Cheers!

Nope. The brake light cannot stay on when ignition is off. What you are seeing is in fact the "park" position of the key. If you turn the key all the way counterclockwise, the handlebars lock AND the taillight comes on. Whether it is the brake filament of the bulb that glows or not is of no consequence.

What I normally do is turn it all the way c.clockwise. and then back one position in the opp. direction. then make sure the bars are still locked. That way Im SURE that the brake light is not on.

The Ignition has two points - On and on. Between those two points is all off. I just learned this.

I finally turned the bike off, and reconnected the battery. Put the new sparks in, checked the petcock, pulled the choke all the way out, and hit the starter. Got 10 seconds of gargling before a hearty roar

Proceeded to dance madly.

I let the engine warm up, and slowly pushed the choke back in, and it sat there idling around 12-1300 rpms With year old gas and dirty carbs.

The XS400 is a bloody wonder.

Took it for a trial run in a parking lot. The clutchwork is tricky but she runs well, and everything from here on out seems cosmetic.

Thanks for all the help guys! I can't wait to hit the road!

get a bottle of carburetor cleaner and gas treatment from a yamaha dealer and pour it in the tank.yamaha sells the best stuff out there.