QuestionHello Mark S.
My nickname is "GMAN". I am not a mechanic but give me a manual and I try anything.
I own a 1992 Yamaha SECA II.
The PROBLEM.
When the bike is turned "OFF" and ignition switch is at "OFF", there is a 2.5 VDC battery drain-checked by placing meter between the NEGATIVE battery post and the NEGATIVE battery cable.
Before replacing the Battery, the drain used to be about 5 VDC.
While diagnosing, by pulling out the fuses, the 30 amp fuse stops the battery drain.
I have checked the charging system and by my knowledge, it seems okay- voltage reading of 14.5 VDC to 15 something VDC (while revving motor the voltage reading goes up). The bike was brought into a shop and techs were unable to be found-stated that it was my riding style and that I should maintain an RPM of 5000 to have adequate voltage to charge the battery.
Please Help!
Any knowledgable response in the right direction will be a truly big help.
Right now, I use a trickle charger to maintain the battery, with the negative lead cable taken off.
Thank You!
GMAN.
AnswerHi G-Man,
My close frined, Gary, shares your nickname. He's a top cop in a small burg in Ohio.
Your question is the best written question I've seen. Very good detail and concise. Compliments and thanks.
The problem:
I suspect the problem exists within the starter solenoid or the start motor. Read below why I suspect these parts.
Inspection:
Current flows from Negative to Positive. Start with the battery and trace flow backwards. The next parts are the main fuse and starter solenoid/relay. You've already eliminated the main fuse. Check the solenoid.
Background intel on solenoids:
Starter solenoids are electromagnents. When the starter button is pressed, 12vdc is applied to the solenoid winding. The solenoid becomes an electromagnet and draws a "T" shaped metal conductor up via magentic field and bridges contacts. High current may now flow to the starter motor for starting the engine.
You will notice small wires and large wires on the solenoid. The small wires are 12vdc to the windings. The heavy wires go to the starter.
Solenoid repairs:
Normally, solenoids are not disassembled for inspection because disassembly requires skilful desoldering and soldering. I often find arcing has damaged solenoid contacts. Dressing up contacts usually restores the solenoid. They may or may not last as long as a replacement part. It is an alternative to buying parts, but your time is valuable, too. Sometimes buying the replacement is necessary anyways.
Back to the troubleshooting:
I would also inspect the starter motor.
Background on starter motors:
Starter motors have carbon brushes that wear with use. As brushes wear, the result is a carbon powder that accumulates in the filed or space inside the starter motor assembly. Excessive build-up of carbon powder can result in a slow or sluggish starter, a seized starter, and require excessive amounts of current to turn the starter motor to overcome resistance from the powder. Starter motors generate heat as a result of the high current flow to start the engine. Excessive carbon build-up insulates the starter motor and increases heat. Carbon is a great conductor and may cause shorting within the starter motor.
Not part of routine maintenance, but periodic cleaning of the starter motor may be necessary to ensure trouble free use. The most common starter is the "Lucas M-3" design. Others include Denso and Kokusan brands. The Lucas starter is easy to maintain and brushes are available for replacement.
Other things to investigate:
Connect your meter (VOM) in series between each solenoid 12vdc lead. Check for current bleeds.
Measure voltage at solenoid winding. Should be no voltage when ignition is off. Should have 12vdc with ignition in "on" position.
Consider ignition swith as problem if all checks out ok.
Keep me advised of your progress.
Respectfully,
Mark Shively
mcso429@netzero.com
(email addy will change to Roadrunner next Wednesday. Use AllExperts if necessary.)
