Help starting

Pdivens

Forum Newbie
Joined
Apr 13, 2017
Threads
3
Messages
8
Cubcadet zero turn. Won t start. Cadet M48-HN (53AB5E6V150) - Cub Cadet Commercial Tank Zero-Turn Mower, 20 HP Honda (2003)?
Mower with GXV620K1 Honda engine will not start. It s been in the shop for 3 weeks without success. Brand new coils spark plugs and battery. Starter motor spins when bypassed doesn t engage when selnoid bypassed. Took out had tested told both were good.

Fly wheel Spins slow when trying to start then click due to battery drain and won t turn. Not getting spark I think because spinning too slowly. New Service tech thinks it s the starter (I don t) you can spin flywheel by hand so that s not the problem either. Doesn t spin while but for a few turn while plugs are out as well. We are both lost. Need help! All cables and electrical cleaned (ground positive safety switches) and checked.
 

cpurvis

Lawn Addict
Joined
Aug 25, 2015
Threads
21
Messages
2,256
How's the battery? New doesn't always equal 'good.' A good battery should spin the engine for a lot more than a few turns, especially with the plugs out.

Check the voltage across the battery terminals while cranking. There's a minimum value, like maybe 10.5 volts that must be maintained while cranking. Should be ~12.7 volts before cranking.
 

Pdivens

Forum Newbie
Joined
Apr 13, 2017
Threads
3
Messages
8
Tried a few different batteries with the same result. It has the proper voltage
 

Pdivens

Forum Newbie
Joined
Apr 13, 2017
Threads
3
Messages
8
Thanks. Easy but expensive if that's the case.
 

BlazNT

Lawn Pro
Joined
Apr 26, 2012
Threads
28
Messages
6,973
Jump the started directly with jumper cables from your car and your lawn mower battery. It is spins from jumping it then it is not bad.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Before you start, pull the spark plug & try to rotate the engine by hand.
No use checking the electrics if you have a hydraulic lock, seized engine or jambed belt overloading the stater motor.
Assuming the engine turns freely.

I like to start from the starter motor and go backwards .
Do the following 5 tests, regardless of the results from an or all of them as there can be more than one problem and you want to isolate where the problem lies.
Elimination of individual parts is important so you know by the end, the battery, solenoid & heavy power circuits are all in good order.

1) try to jump the starter motor directly from your car or truck.
Starter turns = starter good

2) do the same directly from the mowers battery
Starter turns = mower battery good
No turn = duff battery, recharge it & try again.

3) check for voltage ( + 12V ) at the solenoid trigger wire with the key in start position
3a) same with ground trigger wire ( 4 wire solenoid ) or body of solenoid ( 3 wire solenoid)
( I like to test V from the battery hot terminal to ground terminal rather than ohms as they give funny readings )

4) leave ground jumper in place ( from step 2 ) & try key start.
Starter turns = power connection good but ground connection suspect ( most common )
Confirm it by trying again, extra ground removed
I run a secondary grouBefore you start, pull the spark plug & try to rotate the engine by hand.
No use checking the electrics if you have a hydraulic lock, seized engine or jambed belt overloading the stater motor.
Assuming the engine turns freely.

I like to start from the starter motor and go backwards .
Do the following 5 tests, regardless of the results from an or all of them as there can be more than one problem and you want to isolate where the problem lies.
Elimination of individual parts is important so you know by the end, the battery, solenoid & heavy power circuits are all in good order.

1) try to jump the starter motor directly from your car or truck.
Starter turns = starter good

2) do the same directly from the mowers battery
Starter turns = mower battery good
No turn = duff battery, recharge it & try again.

3) check for voltage ( + 12V ) at the solenoid trigger wire with the key in start position
3a) same with ground trigger wire ( 4 wire solenoid ) or body of solenoid ( 3 wire solenoid)
( I like to test V from the battery hot terminal to ground terminal rather than ohms as they give funny readings )

4) leave ground jumper in place ( from step 2 ) & try key start.
Starter turns = power connection good but ground connection suspect ( most common )
Confirm it by trying again, extra ground removed
I run a secondary ground from the grounding bolt to one of the starter mounting bolts & paint over both with liquid electrical tape.

5) Remove the trigger ( thin ) wire / wires from the solenoid.
Ground one & bridge from the hot terminal to the other.
Starter cranks = solenoid good.
Solenoid is not polarity sensitive, BUT THE WIRING IS so make sure you remove the thin control wires.
Note a thinner wire on the hot terminal is not a control wire. It is the main power feed to the mower.


From here on things become very mower dependant as starting circuits are getting changed all the time.
Basically the power goes in a loop from the hot side of the solenoid ( saves wire, no other reason ) through the fuse to the B terminal on the key switch then to the PTO switch then to the parking brake switch then to the solenoid trigger switch , easy peasy after you grow the 3rd arm. Use a test lamp and follow the power.
However a lot of mowers with a 4 pole solenoid, run a secondary ground control circuit to the ground solenoid wire through the lap bars.
Then to stop this interfearing with the normal safety function of the ground kill, it goes to a relay with the ground as the switched connection.
These are a PIA as the + control wire to the relay comes from the power loop above and the ground side of the control comes via the normal cut out functions of the lap bars.
Be very careful because if you have a system like this and accidentally send 12V down the ground loop you can fry the magnetos on some circuits.nd from the grounding bolt to one of the starter mounting bolts & paint over both with liquid electrical tape.

5) Remove the trigger ( thin ) wire / wires from the solenoid.
Ground one & bridge from the hot terminal to the other.
Starter cranks = solenoid good.
Solenoid is not polarity sensitive, BUT THE WIRING IS so make sure you remove the thin control wires.
Note a thinner wire on the hot terminal is not a control wire. It is the main power feed to the mower.


From here on things become very mower dependant as starting circuits are getting changed all the time.
Basically the power goes in a loop from the hot side of the solenoid ( saves wire, no other reason ) through the fuse to the B terminal on the key switch then to the PTO switch then to the parking brake switch then to the solenoid trigger switch , easy peasy after you grow the 3rd arm. Use a test lamp and follow the power.
However a lot of mowers with a 4 pole solenoid, run a secondary ground control circuit to the ground solenoid wire through the lap bars.
Then to stop this interfearing with the normal safety function of the ground kill, it goes to a relay with the ground as the switched connection.
These are a PIA as the + control wire to the relay comes from the power loop above and the ground side of the control comes via the normal cut out functions of the lap bars.
Be very careful because if you have a system like this and accidentally send 12V down the ground loop you can fry the magnetos on some circuits.
 

Pdivens

Forum Newbie
Joined
Apr 13, 2017
Threads
3
Messages
8
Jump the started directly with jumper cables from your car and your lawn mower battery. It is spins from jumping it then it is not bad.

When I jump directly to starter I get the Sam results. When I bypass the selnoid I you can hear it spinning.
 

BlazNT

Lawn Pro
Joined
Apr 26, 2012
Threads
28
Messages
6,973
OK, I do not understand your last statement because jumping the starter is by passing the solenoid.
 

Pdivens

Forum Newbie
Joined
Apr 13, 2017
Threads
3
Messages
8
OK, I do not understand your last statement because jumping the starter is by passing the solenoid.

If I put a screw driver across the poles of the bottom of the starter where the solenoid is attached the starter spins but does not engage. Otherwise when you turn the key the starter will engage but only spin the flywheel a few spins before it kills the battery from cranking it.
 
Top