Had the bike sitting on the work table all winter long. Over the winter I developed a slow oil leak from the bottom of the engine, and an occasional gas leak from the petcock. On the bright side, I finally got my insurance and tag. I was going to take the bike to the Yamaha dealer to work on the charging problem but I reckon the virus scare will put a stop to that for a while. I still love the bike.
-
Enjoy XS400.com? Consider making a donation to help support the site.
XS400.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
It might be a challenge to find a dealer to work on it. Whats happening with the charging system? What tests have you done?
I bought the bike a few months ago. My first ride was great until I got near my house and the bike started busting up. I charged the battery, and it runs great. It reads 12v but does not read any higher when running. I haven't tried anything else.
If youre charging the battery and its only reading 12v, its no good. I expect one season out of a battery. Performing the tests arent difficult with a proper tools. The voltage doesnt change at all with the bike running and when revving it up?
Figure out the battery first, if its the one that came with the bike, get a new one.
Batteries last longer than one season. I will begin load testing at least once throughout the following seasons. New batteries are my piece of mind, especially when you have charging, grounding, regulating issues and other things that may go wrong or maybe you accidentally short the battery posts. Ive gone through batteries in less than a season before too.
Figure out the battery first, if its the one that came with the bike, get a new one.
Batteries last longer than one season. I will begin load testing at least once throughout the following seasons. New batteries are my piece of mind, especially when you have charging, grounding, regulating issues and other things that may go wrong or maybe you accidentally short the battery posts. Ive gone through batteries in less than a season before too.
Last edited:
Specdog
XS400 Addict
If you are using a lithium battery, that changes the game. A Lithium battery is 100% charged at 13.3v and a lead acid battery is 100% charged at 12.7v. If you are getting readings in the 12v range, your lithium battery is finished. A couple of questions for you Cafe, is your Optimate a lithium charger? How old is the battery?
Yes, it is a lithium charger.....the one recommended by the battery manuf.
I bought the bike used, so I don't know how old the battery is.
If the battery takes a charge and the bike starts quickly, but the bike starts to bust up after about 50 miles and then shuts down, and the battery won't start the bike until I charge the battery again, wouldn't my problem be with the charging system?
I bought the bike used, so I don't know how old the battery is.
If the battery takes a charge and the bike starts quickly, but the bike starts to bust up after about 50 miles and then shuts down, and the battery won't start the bike until I charge the battery again, wouldn't my problem be with the charging system?
Specdog
XS400 Addict
It could genuinely be either the battery or the charging system. Charge your battery and hook it up in your XS. Wait about an hour or more until your battery settles down to it's resting voltage. Chart the battery voltage with the key off. Turn the key on and after 15 seconds chart the voltage again. Start the engine and chart the battery voltage, you should see an increase in voltage. Rev the engine to 5000RPM and chart the voltage. Keep in mind this only works with a good battery.
Lithium batteries lose capacity over time. A battery could be 100% charged and only be 85% of original capacity. From what I remember in my R/C days, lithium batteries will put out a constant voltage and then just drop off completely, unlike a lead battery. Electronic ignition requires a minimum voltage to work. Lithium batteries cant handle the constant voltage fluctuations of the bikes charging system.
I use a Antigravity 4-cell, on its 2nd season now. I store my batteries inside during winter and cycle them on a trickle charger once every other week or so. I rode in to work this past sunday which is 90 miles round trip depending on which route I take and most of it is highway....I carried a spare AGM battery with me.
I have a volt meter on my bike and it hangs around 14.2v the whole way. Idle is typically 13.5-8v.
I use a Antigravity 4-cell, on its 2nd season now. I store my batteries inside during winter and cycle them on a trickle charger once every other week or so. I rode in to work this past sunday which is 90 miles round trip depending on which route I take and most of it is highway....I carried a spare AGM battery with me.
I have a volt meter on my bike and it hangs around 14.2v the whole way. Idle is typically 13.5-8v.
Yellow0206
XS400 Enthusiast
Hey Cafe I remember you bought your bike around the same time as I bought mine, last fall....I have since added a second, the 83CB1100F in my profile pic behind my XS400....working on it, and shaking down riding issues with the XS400 now (did my built over last fall) ...quick comment for you on your issues - i thought you bought from the guy who built it, who obviously did a ton of work to it (love your bike!)...isn’t he a resource for you? (sorry if thats an obvious comment and for some reason he is not....)
Yellow0206
XS400 Enthusiast
Ok thks well i wish i had a solution for you - the only thing i can add right now is you mentioned going to a Yamaha dealer - I will tell you 1) they dont know vintage bikes at all in general and 2) with your system with a lithium battery maybe another custom builder in your area can help you since these type of systems seem somewhat common in custom builds....
