KZ 650 B batt overflowing

Hey guys I have had this prob. for some time now. The batttery seems to boil over and then the motor quits. Why is my batt. overflowing or boiling? It has new rect. and volt reg..

It's getting to much juice (volts)from the charging system.
With the engine at idle and a multimeter (on the 0-20 volts DC range) connected to each battery terminal you should be seeing maybe 12.5 or 13 volts. With the engine at 4000rpm you should not be seeing more than 14.5 volts. Any more than that and you have a bad regulater/rectifier or a broken or loose wire. Check all connection and wires associated with the charging system

Connect a volt meter to your battery terminals and measure the voltage on it with the engine at about 4000 RPM. The voltmeter should not read higher than 14.5 V or lower than 12.5. If it's outside that range, I can provide the troubleshooting advice from the FSM.

Typically, an overcharged battery boils out the electrolyte and an undercharged battery goes dead.

NONB; I just checked and at 4000 it is putting out close to 16V.. Thats too much but why is it doing this.

Sounds like regulator problem. Some are servicable, perhaps repairable. Sorry, I don't know more about your KZ650. Others here can offer better advice.

Here's a new combo unit available at Z1E that might fit.

reg/rec combo Z1E

Good luck with repairs.

According to the fsm"

If the reading is more than 16V, the regulator/rectifier is defective and should be replaced with a new one.

This is for a B2A through B4 models. The older 650s had a separate regulator and rectifier, as I understand it.

The manual is mum on the issue of whether a reading higher than 75V can be obtained. I don't know it it's possible that the dynamo output could be too low putting a strain on the regulator causing it to be overloaded.

The regulator rectifier on the B2A and later models is not repairable.

There is a test for the dynamo. Here is what the FSM says:

If your regulator and rectifier are new then it could be just a bad connection. There is a good electrical faultfinding chart for charging systems in the filebase. Click on KZ Information above, then on Filebase, then on not model specific, then select page 5.
Good luck.

To follow up on JR's comment, a poor ground connection may cause your symptom. Per the wiring diagram for a B2A, the negative connection from the regulator/rectifier to the battery goes through three connectors before it reaches the battery connection.

There is a molded plug right at the R/R unit and a bullet connector somewhere else. Then there is another bullet connector on the small wire leading from the battery's negative post. There may be more that aren't explicitly shown.

Suggest using dielectric grease on every electrical connection. Keeps out moisture and prevents corrosion.

On the 650 line, it's critical to know exactly what year you are talking about. There are several charging system configurations for the 650's.

If your bike is after 1977, and has a brown wire going to the regulator/rectifier, then you need to check the voltage on the brown wire at the regulator, using the battery ground as the reference for the black meter-lead. If the voltage there is around 14v, then your reg/rec is fine, and you have a bad connection somewhere... most likely at the fuses or ignition switch. Clean all the fuse holders and measure the voltage on the battery again.

If your bike is a 1977 (evidenced by 3 screws in a triangle pattern on the left-side engine cover), there is a brown wire on the regulator, which is seperate from the rectifier. But the test is the same, and the correction is the same.

If your bike is after 1977 and has no brown wire to the reg/rec, then it's most likely a faulty regulator, but there is a slight chance you have a bad connection from the white/red wire on the regulator back to the battery positive.

Post edited by: loudhvx, at: 2007/05/29 12:46

could have a bad cell in the battery also, making the reg. think it needs more when its the battery all along

thinking of taking the batt. out all together! Ive heard of the bat-pac; a capacitor that replaces battery but cannot use the elect starter anymore. what do you guys think??