How to troubleshoot and replace the starter on an MTD riding mower

     This post details how to troubleshoot and replace the starter on an MTD riding mower model 13AL667F118. This procedure would be similar on many other brands of riding mowers with Briggs and Stratton engines, such as John Deere, Cub Cadet, Toro and more. This is not a difficult job.

                                                    The job at a glance

• Tools: 1/4", 7/16" (or 11mm) and 1/2"  socket and ratchet or wrenches. 
• Materials: None 
• Parts: Starter   
• Cost of parts: $30 (aftermarket)- 73 (OEM) 
• Time: 45 minutes    

Disassembly

The starter is located on the right side of the Briggs and Stratton engine. 

1) Remove the plastic cover for the pinion gear. It is held on by two 1/4" hex head screws.

The pinion cover screws

2) With the cover off,  try to start the engine and watch for movement of the pinion gear and turning of the flywheel. If the gear moves upward but the flywheel doesn't turn,  there may be an engine problem, perhaps even a seized piston. If the starter turns the engine and it won't start, the starter is good. If the starter appears to be dead, move on to step 3.

3) Unwire the red power (B+) cable from the starter. This wire is not electrically hot until the ignition switch is turned to the start position. It is held on by a 7/16" (11mm will also fit) nut affixed to a stud on the side of the starter.

Unbolting the starter

Troubleshooting

     With the lug unwired, this is a good time to confirm that it is the starter that is faulty. There are other upstream possibilities for an engine that fails to start. Attach the positive of a voltmeter (or test lamp) to the lug. Attach the negative lead to an engine mounting bolt. Now try to start the engine and troubleshoot as follows:  

12V present at the lug: Unless the engine is seized, the starter is faulty and needs to be replaced.

12V is present at the end of wire: replace starter

12V not present at the lug: The problem is upstream. The starter solenoid and/or the control circuit will need to be tested. This will be considered in another blog:
http://www.originalmechanic.com/2017/01/how-to-troubleshoot-and-replace-starter.html

Back to removing the starter: 

4) Unbolt the starter. Use a 1/2" (or 13mm) socket to unbolt the starter from the engine. There is a bracket on the left side bolt that is used to as a wire guide. Note the routing of the wire before removing.

Remove two half inch bolts and it's out

5) Remove the starter. 

6) Find a replacement motor. See the end of the blog for possible replacements. 

Reassembly

1) Mount the new starter with the two 1/2" (or 13mm) mounting bolts. Be sure to place the bracket correctly on the under the left side bolt. Snug these bolts up good. They provide the starter ground connection

2) Mount the power wire to the starter with the 7/16 (or 11mm) socket. 

3) Test the starter. 

4) If all is well place the cover back over the pinion gear with the two 1/4" screws.

  

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