Electric start on 640 pulls dead

check battery most likely dead

bad ignition switch

Sounds like a flat battery. Just enough to power your lights but not enough to power the starter motor. Try recharging the battery.and check battery connections are good.

1. Need a new battery
2. starter solenoid is defective
3. starter needs rebuilding...

Does Solenoid click when trying the electric starter? CAREFULLY jump the two terminals on the solenoid (SPARKS WILL FLY).. IF the engine turns over or starts, THE SOLENOID IS BAD. just replace it.
If it clicks when you are trying to start it electrically, use a multimeter (voltmeter) to see if you are getting 12v to the starter connection while you are trying to electrically start it. (+) lead on starter bolt and (-) to a motor mount bolt. If you get 12v+, starter needs rebuilding!

Remove spark plug and observe condition. Fouled with oil, bad motor. With plug removed pull rope several times to blow out cylinder. Spray WD40 in spark plug hole, pull rope several times see if oil blows out. Spray a lot of starter fluid in spark plug hole, replace plug. Spray starter fluid in air cleaner area of carb, try to start. Replace spark plug, try to start. Ensure oil is full, all mowers have a low oil sensor now. 30w oil. Always use Stabile in gas.

You're most likely looking at a dead battery (try jump leads)

A bad starter relay (short out the terminals on top of the relay and see if it turns over)

Or a dead starter motor (service or replace or if it's sticking try rocking backwards and forwards in gear to unstick)

is the battery fully charged and has been tested for no dead cells?
check for voltage at soleniod with key on, if ok jump posts on solenoid to engage starter motor, if starter spins, the solenoid is bad. hope this helps

Assuming your battery is properly charged and has a good connection, it's your starter solenoid (relay) that has failed.

The starter solenoid receives a large electric current from the car battery and a small electric current from the ignition switch. When the ignition switch is turned on, a small electric current is sent to the starter solenoid. This causes the starter solenoid to close a pair of heavy contacts, thus relaying a large electric current to the starter motor, which in turn sets the engine in motion.

If a starter solenoid receives insufficient power from the battery, it will fail to start the motor, and may produce a rapid clicking or clacking sound. The lack of power can be caused by a low or dead battery, by corroded or loose connections in the battery cable, or by a damaged positive (red) cable from the battery. Any of these problems will result in some, but not enough, power being sent to the solenoid, which means that the solenoid will simply make a clicking sound, rather than setting the starter motor in motion.

If these items are all okay, it is likely you need to replace the solenoid.

Have you checked the battery voltage with a multimeter? It should read 12.2 volts or higher. It sounds like the battery is dead, or the charger is not charging.

It starts after it's run because the magneto is slightly charging the battery, plus a cold engine is more difficult to start -- more friciton when cold.

Charlie

does your motor turn over or is battery dead. think you have to pull brake lever to actuate starter. if it does turn over and doesn't start. try draining carb. and to get some fresh fuel in the carb and try again. if not you may need to clean carb.