Engine will not start but solenoid grinds

Click no start is typically a bad battery, bad starter, bad solenoid or loose dirty battery connections. But seems you have covered those items. Have you checked you negative battery cable where it attaches to the frame and motor? Use multi meter and check from positive of battery to the motor(block) for 12 volts. Also do this while turning key to start position. If voltage drops out when doing this double check battery voltage and all connections. If it does not drop then check the solenoid wire coming from ignition. When key in start position you should have a good twelve volts. If you you do then test the main leads hooked to solenoid for power. If solenoid wire from ignition has less than 12 volts double check connections at battery and also test the clutch pedal switch.

For a more specific answer post the following information: Make/Model/Year/Engine Model/Deck Size, and hours on meter if you have one. A short description of the events preceding the beginning of the problem is also helpful.

The following generic information applies to just about every riding mower out there.

When you turn your key many things happen. One of those happens only when you turn all the way to start. In this position current, from the battery, travels down a small wire to your "starting solenoid". You can find this solenoid by following the very large wire backwards from your starter motor on the side of the engine. This very large wire carries a lot of current from the solenoid. Follow the wire down and you will come to a small, somewhat cylindrical device. It's about the size of a large pill bottle; maybe a big bottle of aspirin.

This little device has a magnetically operated plunger inside. When you turn your key the current running down a small wire comes to this solenoid. As it passes through the solenoid it activates the electro-magnet inside. That magnet pushes two thick contacts together. Those contacts bridge the gap between the two large threaded posts that you see on the end of the solenoid.
One of the two large posts has a heavy, thick, wire coming from the battery. The other post has the wire that goes to the starter. While the (internal) contactor bridges the gap between these posts, lots of electrical current flows through the big wires. This causes the starter to turn.

When you release the key from the start position, back to the run position, the internal contactor is pushed away from the posts by a spring. That causes the starter motor to cease turning. It sounds like the spring is broke or the contacts are mildly welding themselves together. In other words the internal contactor is stuck in the "on" position and this keeps supplying current to the starter.

The first problem, broken spring, is the easiest to fix. Just replace the solenoid. There are no internal serviceable parts.

The second problem "internal welding". That might also be fixed by replacing the solenoid. However there is a chance that this is being caused by the starter drawing too many amps or too much current (that's basically the same thing). You will need to test the amperes being drawn by the starter with a clamp style amp-meter. You might have to replace or service the starter. If the starter is drawing too many amps, a new solenoid will likely solve the problem for a while, but then it too will start to weld. Additionally, a bad starter pulling too many amps will damage the battery in a short period of time. You may have to replace both the solenoid and the starter.

One test you should perform is a voltage measurement of the battery while the starter is cranking. Switch a volt meter to DC Volts and clip it across the battery. It should read between 12-13 volts. Leaving the meter connected to the battery, crank the engine. If battery voltage drops below 9 volts when cranking, or while the engine is running, the fuel solenoid will not function. That means the engine will not start or will die soon after starting. So check your battery voltage before, during, and after cranking. If the battery voltage is good (12.4 or greater volts) before, but drops near or below 9 volts while cranking, this is generally a sign the battery has one or more bad cells. Replace the battery. If the battery is in fact good and the voltage is still dropping you may have a bad starter motor which is drawing too much amperage.

Note: many systems have a fuel shut off solenoid. This is a small black cylinder on the bottom of the carburetor. It has two wires running to it. It should make an audible click when you turn the key on.

Another possibility is the Key Switch. The Key Switch may have broken up inside and the multiple terminals which provide current to multiple devices on the tractor have become misaligned. This could cause both of the symptoms you described. The engine won't start AND the starter won't quit. If the terminals are faulty other parts of the system may not be engaging and the engine will not have the proper electrical connections for running. Additionally, the starter solenoid may still be getting current while the key is in the run position.

TEST KEY SWITCH
Put meter in the DC volt position. Disconnect the small wire from the solenoid. Connect one meter lead (red) to this wire and connect the other meter lead (black) to the negative post on the battery. You should see the following:

1. Key off - No volts
2. Key in Run position - No volts
3. Turn and hold key in start position - you should read 12+ volts
4. Release key back to run position - it should go back to No volts.

If your readings are like this the Key switch is good. If there is voltage present in the Run position, your key switch is bad. Replacing it will fix the problem.

Sounds like the battery is weak. Yea 12 volts its good, but it needs it under the load also. Your local auto parts store Sb able to test it

with a volt meter set to DC, pull the wires off of the starter solenoid coil (the small wires) and check for 8 - 12 volts DC at the wires when the key is turned. A poor connection at the solenoid coil will cause slow turning engine cranking or none at all.
If you have 8 - 12 volts there check for voltage to ground on the large cable that goes from the solenoid to the starter motor, one probe on the cable and the other on ground or ( - ) at the battery. Turn the key to start, if you have voltage to the starter motor but it does not turn loosen and retighten the mounting bolts to the starter motor and if that does not help do the same for the engine to ensure you have a good ground. If none of that works your starter motor needs to be replaced, if you have no voltage to the motor the solenoid or battery connections are faulty.
You can also quickly test starter health by conecting a set of jumper cables to a good battery, clamp the neg. to the engine block anywhere and tap the pos. to the starter cable connection from the starter solenoid, if the engine spins over your starter is healthy and the issue is certainly between the key switch and the starter solenoid.

I'd use digital multimeter across battery posts, everything off, the generic spec for a full charge is 12.6 volts. Leave the meter leads touching the battery posts, have helper turn key to crank, what is the reading, It shouldn't drop below about 9 volts. If it drops down to almost zero, I'd have to test the battery. If it is open top battery, where you add battery water, you could use digital multimeter to check each cell, 2.1 volts.
You could do other checks? Maybe something is making the engine hard to turn over?

Check connection battery,could be starter.

your battery is in a weak state also the solenoid is shorting out replace the solenoid

make sure the car is out of gear then put a spanner on the crankshaft nut to try and turn the engine over. if it wont turn then the engine is most probabl siezed

Update....

Haven't had a chance to verify this for certain, but, I learned that if the starting system is in "interrupter mode" the engine will turn over, but not start. In my case, it will not turn over.....suggesting that my problem may lie elsewhere! This would prompt me to check my electrical circuits, cables,etc. Since I have lights, I would check my smaller lead running to the solenoid. With a volt meter...set on DC volts, closest to the voltage in question (in this case, 12 volts) ground the black lead of your volt meter to clean connection on engine or frame. Put the red lead on the solenoid terminal of the starter (the smaller of the two leads) Have an assistant turn key to starting mode. If you experience a voltage drop of 0.5 of a volt, but still dosnt activate solenoid, this would prompt me to check solenoid. To gain access to starter, remove heat shield. Before you procede with any procedure, disconnect the negative terminal of the battery. Make sure it does not come back into contact with terminal, as wire tends to have a "memory".

Its colder than hell right now...so havent had chance to follow up

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