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Hey all. I'm new to the forum and in need of some help. I've inherited a Scott 17.5 42 from my parents. Model CV491S. Spec # 27509. SN 3126202963. They were having a lot of trouble with it and bought a new Kabota. At first the mower wouldn't crank so I started jumping safety switches and found that it needed a new clutch switch and seat switch. They had already replaced the starter. I checked the ignition coil with a voltmeter and it appears to be good. Also took the starter apart and checked brushes and coils. Nothing appears to be burnt. Now it's blowing the fuse between the battery post/solenoid and the starter. I had the battery checked and it was good. I also used another good battery to test and it started and blew a fuse. Then I hooked jumper cable to battery and bypassed solenoid to starter and it doesn't spin. I'm running out of ideas. The mower itself is in really good condition as well as the motor. Hate to trash it.

If the mower is in that good to shape you need to start by fixing the safety switches first you have jumped out, then continue your trouble shooting from there.
But from what you have stated safety switches and solenoid would be my first replacement parts and I would do this before you continue jump starting and burn everything else out.

Welcome to LawnWorld!

We moved your thread to the Small Engine & Mower Repair forum.

Nwatson99 said:

If the mower is in that good to shape you need to start by fixing the safety switches first you have jumped out, then continue your trouble shooting from there.
But from what you have stated safety switches and solenoid would be my first replacement parts and I would do this before you continue jump starting and burn everything else out.

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Thanks for the reply Nwatson99. I replaced the clutch and seat safety switches prior to bypassing starter. Motor wouldn't turn over until I did that.

A lot of red flags and questions come to mind while reading this thread. First, are you saying that all safety switches are now in place? Second, you cannot test today's ignition coil with a volt meter, as you will get inaccurate readings due to the built in capacitor. Third, did you say that you disassembled a new starter? Fourth, I don't know how you can bypass the solenoid with a jumper, unless you connect it directly to the starter? If that is what you did and the starter does not spin you have a bad starter. If you are blowing the fuse, you should be looking for a short in the starting circuit, which has nothing to do with the ignition circuit. Please explain, as I am very confused.

Rivets said:

A lot of red flags and questions come to mind while reading this thread. First, are you saying that all safety switches are now in place? Second, you cannot test today's ignition coil with a volt meter, as you will get inaccurate readings due to the built in capacitor. Third, did you say that you disassembled a new starter? Fourth, I don't know how you can bypass the solenoid with a jumper, unless you connect it directly to the starter? If that is what you did and the starter does not spin you have a bad starter. If you are blowing the fuse, you should be looking for a short in the starting circuit, which has nothing to do with the ignition circuit. Please explain, as I am very confused.

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All of the safety switches are in place.
Replaced positive battery cable.
Checked ignition switch per shop manual. Ok.
I tested the ignition coil (continuity) per the shop manual. Mower is 2002 vintage.
I did take the starter apart and tested it with battery cables. It works.
You can take a screw driver and lay it across both posts on the solenoid.
I've also checked the ground from the battery to the frame and replaced the solenoid yesterday. Motor started right up and when I mashed the gas it blew another fuse. I know it has to be a short or loss ground somewhere, but it isn't obvious.

treeninja said:

All of the safety switches are in place.
Replaced positive battery cable.
Checked ignition switch per shop manual. Ok.
I tested the ignition coil (continuity) per the shop manual. Mower is 2002 vintage.
I did take the starter apart and tested it with battery cables. It works.
You can take a screw driver and lay it across both posts on the solenoid.
I've also checked the ground from the battery to the frame and replaced the solenoid yesterday. Motor started right up and when I mashed the gas it blew another fuse. I know it has to be a short or loss ground somewhere, but it isn't obvious.

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It is a short if I was betting, I have never been able to get anything to start with a loss /dead ground.
So you step on the gas and blow a fuse, sounds like back feed which could be over charging of the alternator or do you have a voltage regulator on that machine that could be another culprit.
Try this but not for long just to check, most mowers have a 10 or 20 amp fuse, put a 30amp in that guy and let it idle, then just touch the wiring and see if any wiring starts to heat up or discolors.

Nwatson99 said:

It is a short if I was betting, I have never been able to get anything to start with a loss /dead ground.
So you step on the gas and blow a fuse, sounds like back feed which could be over charging of the alternator or do you have a voltage regulator on that machine that could be another culprit.
Try this but not for long just to check, most mowers have a 10 or 20 amp fuse, put a 30amp in that guy and let it idle, then just touch the wiring and see if any wiring starts to heat up or discolors.

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"Try this but not for long just to check, most mowers have a 10 or 20 amp fuse, put a 30amp in that guy and let it idle, then just touch the wiring and see if any wiring starts to heat up or discolors."


What the hell is this...?

Only put a 30 amp fuse in if you want to take a chance on replacing the entire wiring harness. I would start the engine and see if it will run properly with the voltage regulator disconnected. If it continues to run and not blow a 20 amp fuse, you know your problem is in the charging circuit.

Rivets said:

Only put a 30 amp fuse in if you want to take a chance on replacing the entire wiring harness. I would start the engine and see if it will run properly with the voltage regulator disconnected. If it continues to run and not blow a 20 amp fuse, you know your problem is in the charging circuit.

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Thanks Rivits. Do I need to remove all three wires (2 white, 1 black) from the voltage regulator? I had planed to check the stator this weekend. Has to be the regulator, ignition module or stator. All of the other connections are tight and I don't see any fried wires. One thing I did notice yesterday when I took the fan off to get to the fly wheel that it appears I'm missing a key where the fly wheel fits over the shaft. Fly wheel is on tight though. I noticed a painted mark on the shaft. Should this line up with the slot that holds key? Going by Harbor Freight and pick up a puller this afternoon.

There will be a key way in the flywheel and in the shaft. and its best to remove all the wires from the reg/rec.

EngineMan said:

"Try this but not for long just to check, most mowers have a 10 or 20 amp fuse, put a 30amp in that guy and let it idle, then just touch the wiring and see if any wiring starts to heat up or discolors."


What the hell is this...?

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Hey Engine Man. I appreciate any comments I get. That was not my response to your reply. Treeninja. And thanks for the advice.

treeninja said:

Hey Engine Man. I appreciate any comments I get. That was not my response to your reply. Treeninja. And thanks for the advice.

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I pulled the flywheel from the motor and did find a half moon key. I cleaned a rat nest from under the flywheel and around the magnets, checked the ignition module continuity and it checked out +/- 10200 ohm. Removed stator and no signs of over heating or bare wires. Battery voltage on black wire to voltage regulator with key on. Continuity between stator leads and ground. Cranked the motor with stator leads disconnected from regulator/rectifier and drove mower down driveway and back (1200 feet) with no problem. Hooked the stator leads back up and blew the fuse trying to crank it. I believe its a bad regulator/rectifier. Can't check voltage of stator lead with mower running because it blows fuse. Any thoughts before I buy a regulator/rectifier?

Before you buy a reg/rec check the stator assy, make sure that the coils are not grounding and defective in anyway.