Just bought my first motorcycle! 1980 XS400 Special!

[codypants]

Well I'm Cody and I'm new to the forum but have been browsing it the past month before buying my first motorcycle. I bought a 1980 Yamaha XS400 Special for $750. Hoping to gain some knowledge from this site and help others when I can!

So far the bike runs pretty well, I have about one days riding experience. Just hopped right on and caught on quick. It seems to have a few issues, which hopefully someone can shed some knowledge upon me!

* It doesn't like cold starts all that much. I have to use the choke for a few minutes otherwise it will die right away. Won't really stay running without giving it gas before it's warmed up.

*It died on me after it warmed up and I was on the road for about 10 minutes, and came to a stop. Had a hell of a time starting it back up, the battery seemed like it was completely dead. I had to use the kickstarter to get it going, but that took several tries. It died 3 times on the way home, every time I came to a stop. The battery is brand new, and is being charged by Autozone right now because they said it was at 0%. I'm not sure if I did something wrong or if something is killing my battery that I'm not aware of.

I attached some pictures of my bike, without the seat.
Thanks all!

 

[arfstrom]

First off, Welcome to the group! Nice bike, looks just like mine, (1981, 4R4) that 4R4 is the first part of the bikes serial number, (kinda helps figure out if there was a major change from your bike to mine)

(when you have a second, go to the control panel, and put some of that info in the signature, so some time in the future, you wont have to remind anyone what bike your working on.)

On to the first problem. Battery not keeping a charge. This generation of bike has tendency to burn out some wires. if your ready for the technicality of it, the three stator wires like to burn out right where the wires come out of the engine, and turn up to a white connector. My recommended fix for that is test the theory (always test theory prior to jumping to conclusions) Pull the seat off, find the connector at the front of the seat, connector will have 3 white wires, disconnect it. Feel the wires right around the connector. you find that those wires there are stranded, and typically tinned, very flexible. as you work the wires done to the back of the motor, you will feel the wires are getting brittle, and you will feel snap-ing, and crackling. It is only those three wires. My supposition is that that the stator is creating enough energy, that on its way to the regulator, rectifier and the 90 degree turn upwards, tends to focus any energy that isn't following the flow up, to "create a static spot" for lack of technical explanations, which means its just going to create a traffic jam there at the corner, and burn out.

Other suggestions before we direct you to follow "Drewpies Re-wire" program (just the stator portion) validate that the Regulator and rectifier are not shot.
http://www.xs400.com/forum/showthread.php?t=10715 Willems Bunch of How to's in a thread. This has a category with the re-wire. As well as the Tech tab on top of this page.

http://www.xs400.com/forum/showpost.php?p=127447&postcount=17 Here is the Manual. (don't do what the rest of the people do, when they don't read the rest of the thread) it is 45 megs download.

I might have overloaded you with the images, I am sure you will get over it. Don't be afraid to look at the sticky on top of the garage, has parts catalog, and other valuable repair manuals. As much as we love answering questions, (we hope people will use the google search, and YouTube,)

The minor problem with it choke-ing, is just a sign that your due for a carb cleaning. you might get lucky with using a carb cleaning, to clean out your problem, (sea-foam, would be my recommendation, other good ones out there) Stop using fuel with ethanol.
(if you drive daily, ethanol is okay, but for the last few tanks of fuel before the end of the season, its not okay) I have had it gum up after sitting for 3 days of no attention. You will of coarse need to allow the sea-foam time to run though the three spots on the choke, so it gets rid of the gumming.

Is there a fuel filter between the petcock, to the carb, put one there. Well worth it. Soo is a battery tender.If you go with the battery tender, you will find they have a neat little voltage gauge, for another 15 bucks off of amazon.

Well Cody, nice to meet you, Tobie