Mower will not start

[Old Murray]

This is my first post on here so if I have left out pertinent info I apologize ahead of time. I'll do the best I can to describe the problem and hope someone has an answer.

I have a Murray riding mower model# 425007x92. It has a Briggs motor. When I try to start the mower I get 12 volts on the pole on the battery side of my 3 pole solenoid but only 3 to 5 volts on the starter side and the same voltage (3 to 5) on the pole attached to the ignition switch. When I turn the key the starter makes a half turn and then the solenoid starts clicking. When I remove the wire to the starter and turn the key I get 12 volts on all three poles. The solenoid is brand new (two days old) and the battery is fully charged. Also, when I remove the spark plug the starter turns with no problems but the voltage is still low on the starter side pole and the ignition switch pole. Clearly, something is wrong, but I don't know what it is. My guess is the starter, but it is just that; my guess. I disassembled the starter and the brushes appeared to be in good shape and, from what I could see, the windings looked good, but I know you can't see all of the windings so that's why I'm not sold the starter is good. My other guess is the spark plug. Any ideas? If you think I should test the starter can I do that with a multi-meter and, if so, how would I go about testing it? Thanks in advance.

 

[silver1]

This is my first post on here so if I have left out pertinent info I apologize ahead of time. I'll do the best I can to describe the problem and hope someone has an answer.

I have a Murray riding mower model# 425007x92. It has a Briggs motor. When I try to start the mower I get 12 volts on the pole on the battery side of my 3 pole solenoid but only 3 to 5 volts on the starter side and the same voltage (3 to 5) on the pole attached to the ignition switch. When I turn the key the starter makes a half turn and then the solenoid starts clicking. When I remove the wire to the starter and turn the key I get 12 volts on all three poles. The solenoid is brand new (two days old) and the battery is fully charged. Also, when I remove the spark plug the starter turns with no problems but the voltage is still low on the starter side pole and the ignition switch pole. Clearly, something is wrong, but I don't know what it is. My guess is the starter, but it is just that; my guess. I disassembled the starter and the brushes appeared to be in good shape and, from what I could see, the windings looked good, but I know you can't see all of the windings so that's why I'm not sold the starter is good. My other guess is the spark plug. Any ideas? If you think I should test the starter can I do that with a multi-meter and, if so, how would I go about testing it? Thanks in advance.

Welcome.

Make sure the GROUND is as good as the +12. If you have the starter off, ground it to the frame or neg. side of battery connect wire from solenoid and test it. You can go right from +12 to the starter also. Be careful of of sparks......if jumping to the starter.
There will not be a load on it, but it should spin free.

 

[Old Murray]

Thanks for the quick reply. I will try that. I forgot to add that I tested the ground on the ignition switch and on the solenoid to the ground on the battery and they were .04 & .05 ohms. I compared those to a bare metal spot on the mower to ground and it was .04 ohms, too. I didn't, however, test the starter to ground. I wasn't sure where to test it at. But, I will try the starter test to +12v like you suggested.

 

[silver1]

Thanks for the quick reply. I will try that. I forgot to add that I tested the ground on the ignition switch and on the solenoid to the ground on the battery and they were .04 & .05 ohms. I compared those to a bare metal spot on the mower to ground and it was .04 ohms, too. I didn't, however, test the starter to ground. I wasn't sure where to test it at. But, I will try the starter test to +12v like you suggested.

The starter is grounded to the engine, the engine to the frame as is the -neg. post of the battery.
If you turn the switch to "run" and jump +12 to the starter nut it should turn and if all else is good, start.
good luck

 

[Old Murray]

Thanks for your help. I put jumper cables from my truck to the battery on the mower just in case I was wrong and my battery wasn't fully charged. The starter would spin two or three times then quit. I tested my mower battery and I was over 13 volts because I did leave the truck running the whole time. I then removed the jumper cables from my mower battery and connected the ground to the frame and touched the positive directly to the starter. The starter would spin a couple times then stop. Of course I couldn't leave it on there because I would weld my jumper cable to the starter. Seems to me that the starter should continue to spin over and over again, not just a couple of times then stop. Am I wrong?

 

[silver1]

Thanks for your help. I put jumper cables from my truck to the battery on the mower just in case I was wrong and my battery wasn't fully charged. The starter would spin two or three times then quit. I tested my mower battery and I was over 13 volts because I did leave the truck running the whole time. I then removed the jumper cables from my mower battery and connected the ground to the frame and touched the positive directly to the starter. The starter would spin a couple times then stop. Of course I couldn't leave it on there because I would weld my jumper cable to the starter. Seems to me that the starter should continue to spin over and over again, not just a couple of times then stop. Am I wrong?

No, you are not wrong. It should spin the complete motor.
Did you say that if you took the spark plug out it would turn
over longer? There should be no difference!

If you shop ebay you get a starter there. Or Lawn Mower Parts.


Off to the 500.

 

[Old Murray]

Yeah, I thought I would definitely be able to find out if the starter was bad by decreasing the resistance of the motor turning thereby making it easier for the starter to spin the motor even with the low voltage (3 to 5 volts) the starter was getting. I did that by taking out the spark plug and removing the combustion from the motor. The starter did spin the motor over and over without stopping. When that happened it created a little confusion for me because I thought if a starter was bad then it wouldn't work correctly no matter what. After I put the spark plug back in the starter went back to only spinning the motor just a little bit before stopping and, of course, the voltage to the starter remains low (3 to 5 volts).

 

[AnthemBassMan]

If the engine turned over fine without the plugs in, and if your engine has overhead valves, it sounds like the the valves need adjusted. It's not a hard job to do. All you need is a set of feeler gauges that go down to .003", and you're on your way...

L8R,
Matt

 

[Old Murray]

Turns out that the valve adjustment was what it needed. I adjusted them and the mower started right up. Of course when it started the choke was stuck wide open so I turned the mower off and since I thought I had the problem resolved I went ahead and put sealant on the valve cover gasket, reinstalled the valve cover then fixed the choke. When I tried to start it back it was doing the same thing as before. I will have to wait to get more valve gasket sealant and since I had time I thought I would ask if .003" is the normal settings for both valves on this mower? I tried to find something online telling me what the correct settings are, but I haven't found anything yet. My mower has a 17.0 HP I/C OHC motor. I can't find a serial # or anything to it, though.

 

[AnthemBassMan]

-The intake valve should be set between .003"-.005", and the exhaust valve should be set at .005"-.007".

L8R,
Matt