Topic: Newbie 75 CB400F Problems

[broken]

Hey all, new to bikes for the most part and just got a CB400 on the road, been running fine for about four days now. The horn wasn't working so I swapped in a new one today, seemed to work fine although kinda quiet. I continued to run some errands starting and stopping the bike 3 or 4 times in a couple of hours, stopped at a garage sale on the way home and the battery seemed dead when I tried to leave. Fella was nice enough to give me a push start but when I got home battery's completely dead it would seem.

I had a couple of questions, should I be able to kick start the bike with a dead battery? Secondly, is charging a bike battery just like a car battery? What else could this be, lights don't work at all horn doesn't work start button does squat? I think I may have reversed the leads attached to the horn, would that kill the battery? I swapped them to the correct positions now, should charging the battery solve all my problems?

[kghost]

How old is the battery?

Charge rates for motorcycle batterys are less then for cars. They have less amp/hr capability. Try 2 amps as about the max. Other than that its like any other lead acid battery. Check your electrolite levels.

Make sure your not lugging around all the time below 3k rpm. Also make sure you are not leaving the tail light on when you remove the key. (you probably know that there are three positions on the switch but you never know. My wife leaves hers on all the time.)

[broken]

I probably have been going slow, guess I'll get the battery charged and find out. Should I be able to start the engine with the kick start dispite a dead battery?

[kghost]

Generally yes. unless its completely dead. E.I. all the acid leaked out.

If you have a old battery it may not charge regardless.

Check your voltage with a meter across the plus/minus with the bike running. Good charging system should provide 13.2 at 4000 RPM.

[kyre]

these old bikes charging systems aren't the best. if you do a lot of city riding or stop and go short distances then the batery with eventually die. I do mostly city riding and I have to charge the battery every once in a while if I dont get on the highway to let the battery charge. it's not that big a deal for me really. did you try to kickstart it? if you can bump start the bike then you should be able to kickstart it.

[broken]

I can't seem to kick start it, I put it in neutral, turn the ignition to on and the gas to on and hit the kick start, it turns over but doesn't start, the headlight and signals do not respond at all to the controls. The battery, unless a shop screwed me, should be new from Wednesday but I have been riding in the city so I wouldn't be surprised if it that's the cause, but I'm confused as to why it won't kick start. Could someone outline in detail the kick start proceadure? I'm green here, I don't think I'm missing anything but dunno. Thanks.

[kghost]

Sounds like my kick start proceedure.

If its cold I'll sometimes hit the kill switch (ignition off), push it through a couple times to prime the cylinders, then ignition on and kick it.

[kyre]

ignition on, killswitch to run, gas on, choke all the way up. you always need to choke a cold bike if your choke works. the choke is a little lever right under the fuel petcock (which turns the fuel on/off/reserve) I'm sure you know some of this but you did say you were a newbie. ok gotta go ride now.

[broken]

Yeah, that's what I'm doing to kick start it, the engine turns over but doesn't start, and things were going so well.

[78_SaltLick]

Hi from one newbie to another i was just asking the same questions as you last week. My battery went dead, it was only 2 weeks old. I found out a few things contributed to this.

1. I was riding around in 100 plus degree heat. This will kill your battery, and dry out the water in the battery.

2. I was riding around town, or in parking lots trying to get use to the clubman handlebars i just put on, never really even getting into 3rd gear. This will drain off the battery. You have to get it up in RPM's over 3000 ive heard before it starts to recharge the battery.

3. I was working on my bike alot, so about twice a day for 2 weeks i was starting it up, and idleing it for about 10 minutes a day. This was also draining my battery.

Basically, what i am going to do is buy a battery tender, or whatever they are called. Whenever i park my bike at home for the night, hook that up. It will keep the battery charged when im not riding it, but will not over charge it.

I thought that bikes were like cars, but i guess not. The batterys go dead easy, unless your riding it every day on the freeway, or at least most of your drive is over 40mph.

[Gordon]

If your battery charge is too low, it won't run at all even by kickstarting.  If that's really a new battery, then I would suspect either a short somewhere that's draining the battery, or a significant problem with the charging system.

[broken]

Okay, update, I picked up a Battery Tender and charged the battery, looking good at 12.45 Volts. I also checked the Ohms across the battery leads with the battery detached, it shows with the key in the OFF position everything's fine but in the ON position there's 0 resisitance, I assume the headlight should have some resistance, this seems to point to a fault no? Any very common faults I should start with? Also how do I remove the gas line? Do I just pull it off the little plastic cone past the valve?

bro`ken

[Bodi]

You're going to see 0 ohms load with most meters, the headlight and ignition take a lot of power. If the fuse doesn't blow and the headlight lights it's OK.
The best thing to start with is a good cleaning of all the bullet connections. There's a big wad of them under the tank beside the frame just behind the steering stem, lots in the headlight shell, and the alternator circuit has a set under the left engine cover. These get corroded and cause many electrical problems. If you do them one wire at a time you won't get mixed up, unplug the bullet and clean the male end with fine steel wool and the female end with a Q-tip and alcohol or contact cleaner. If the connection seems at all loose, tighten the female end by gently squeezing it with pliers. If the connection is severely burnt looking, you may need to replace it with new terminals or even sole\der and insulate the wires - a last resort for wires you may want to disconnect. The alternator connections under the engine cover don't really ever need to come apart as the engine plug can be disconnected to remove the engine or alternator. The 5 alternator wire bullets in there cause a lot of trouble, probably because they are as hot as the engine when riding and get some oil contamination and I usually solder them when I see signs of connector overheating.
After the wiring harness has bee serviced this way you can start looking for "real" problems with the alternator, regulator, and rectifier.
Most bikes with charging problems are OK after the connector cleaning though.

[broken]

Will do, thanks fot the info. Just for more symptoms, in about 1.5 hours of driving the battery will drain from 12.5v to 11.5v, when I rev over 2000 or 3000 RPM the voltage jumps but doesn't even reach 13v. I'll clean the connections tonight and hopefully that'll do her.

bro`ken