Model #917378491 CRAFTSMAN Walk Behind Lawnmower, Gas

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Mower won't start 917378491 Craftsman Gas, walk behind lawnmower


Thanks for the inquiry and for using
Sorry to hear of the issue your having getting the engine starter, I know how frustrating that can be to have occur. 
I would start by verifying that you have spark to the plug. To do that, you will need to pull the spark plug from the cylinder and once out reattach the plug wire/boot to it. With the plug connected, ground the base of the plug to the metal cylinder of the engine and have a helper pull the rewind starter. If you have spark coming from the base of the plug while grouding it out on the engine, the spark is good. If not, you will need to replace the spark module.
If spark checks out, I would obtain some starting fluid/ether and squirt a little into the throat of the carb. From there, pull the rewind starter to see if she will fire up. If so, the issue will be internal in the carburetor and will need a good thorough cleaning. I would pull the carb, open it up, and with a full can of carb cleaner, a wire brush, and a bread tie wire to poke through and clean the main jet; do a thorough cleaning and pay close attention to the needle/seat area of the carb. Once you wire brush it, douse it liberally with carb cleaner. An air compressor works well with carb cleanings as you can shoot compressed air into the crevices and air passageways, as well as the main jet. 
I would suspect your issue will be with one of the two suggestions above. Hope this helps and thanks for using We appreciate your business. 

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Jeff Wallace Sr -
Sears Technician
June 26, 2014

How do I replace the pull cord on Model #917 378491? 917378491 Craftsman Gas, walk behind lawnmower


Thank you for choosing Sears Parts Direct. I can certainly assist you in locating the instructions to replace the starter rope on your mower. I did look into the model number you have provided and I recommend double checking to make sure the parts are installed correctly.

NOTE: Please be careful with the springs as they can fly out and hit you. We recommend the whole assembly rather than repairing it. The starter spring will unwind violently if it gets free and can cut you or damage an eye.


1.  Disconnect the spark plug wire from the spark plug.

2.  Remove the three bolts holding the starter shroud to the engine. Lift the starter shroud off the engine and place it upside down on a work table
3.  Hold the  engine shroud with one hand and turn the center pulley inside the shroud clockwise with the other hand until the pulley won't turn any further. Clamp the pulley in position with the wide-jaw pliers.

4.  Grasp the knot in the knot hole with a pair of needle-nose pliers and pull out the broken section of rope.

5.  Insert the end of the replacement rope (with the handle installed on the other end of the rope) through the hole in the starter shroud and into the pulley. Pull the rope through the hole with the needle-nose pliers until about 12 inches of rope extends through the knot hole.

6.  Tie a tight knot in the exposed end of the rope. Singe the end of the rope with a lighter or match to keep it from fraying.

7.  Pull the rope from outside the starter shroud until the knot is tight in its hole.

8.  Release the wide-jaw pliers and allow the rope to recoil into the pulley.

9.  Place the starter shroud back on the engine and tighten the three bolts to secure the shroud in place. Reattach the spark plug wire on the spark plug.

You can also visit for parts, diagrams, and repair information.



If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website: Sears Home Services .

Thank you for your question. Have a great day. 

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Natasha12 -
Sears Technician
June 25, 2014

how do i replace the gear, 183499 in model number 917.378491

A: is a great place to find answers to replaceing parts on a lawn mower. The expert will be with you shortly with information on the part 183499 27 teeth gear. Thanks for your patience.

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Anna T -
March 25, 2012

To replace the belt you need to remove the drive cover from the top of the deck. Push down on the gearbox pulley and remove the belt from the pulley.

Turn the mower on the side with the carburetor down and remove the blade, blade adapter, and the debris shield that is covering the belt.

Remove the belt from the engine pulley and remove the belt.

To replace the gearbox, remove front tires, e-clips, pinion gears, and dust covers.

On the gearbox remove the drive cable from the gearbox cover. Remove the spring on the rear of the gearbox and rotate the gearbox so you can remove the spring underneath.

Slide the gearbox to the left far enough that the right axle will drop out of the opening in the wheel adjuster assembly.

Slide the gearbox to the right far enough that the left axle will drop out of the opening in the wheel adjuster assembly.

You can now remove the gearbox for repair.

Remove the 4 bolts holding the gearbox together. Separate the top of the gearbox from the bottom. You will have to drive a screwdriver between the 2 halves and pry them apart. The gearbox is sealed with RTV sealant.

Lift the axle out of the gearbox and slide the bushing, washer, and gear off the end of the axle. Clean all the old grease out of the gearbox and from the axle and gears.

Install the new gear on the axle with the bushing and washer. Slide the new gear over the 2 shaped wires on the shaft.

Coat the new gear, shaft, and the lower gear with a heavy coat of good quality axle grease.

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Jimmy K -
Sears Technician
March 27, 2012
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