The only ones that use the metal gears came w/ them . Model and code # could help locate the proper gear or drive. Yes, there is a correct way to install the gear. You will note the taper on gear goes up towards the ring gear. Other possible issues are damaged ring gear, worn starter or worn pinion. Use only the Briggs OEM drive parts for best results.

Could something have fallen into the spark plug hole, that would make the piston stop moving?

Valves adjusted too tight ?

Good news! I had the gear in backwards. I just put a new one in the correct way and it is engaging. Bad news: I forgot to put the "c" shaped washer on the starter. I have it apart now, but I am not sure which way the washer goes. Please help. Thanks!

Well I have broken two more plastic gears. Does anybody have the procedures for adjusting valves on a Intek 21 HP B&S engine Dual OHV? I've adjusting these thing at least three times over the years, but maybe I have forgotten how. Thanks!

I took the starter to a local business, and they said that the shaft had some resistance that should not be there. I purchased the pinion gear and took the starter home and started taking it apart. The brushes were good, so I started to pull the shaft out, when I found one of the four magnets attached to the shell had fallen off. Viola! I believe I have found the problem. I glued it back on with liquid nails and will give it a go this Friday. Wish me luck.

Luck!

Well, it still won't start. Could using liquid nails to hold the magnet on cause any issues with the magnetism? I tried to jump start the mower with my truck tonight, and after revving the truck engine up, the mower turned over better, but still not running. I'm trying my neighbors battery tomorrow, and if that doesn't work, I guess I'll pull the starter again. Any help appreciated! BTW, I re-re-rechecked the valves again tonight.

Well, it was already too late to mention that the magnets (as all magnets do) have a "North and South" pole.
The magnets are oriented in a specific manner on the field case to cause the armature (rotor) to spin in a certain direction.
The Liquid Nails product does not in itself affect the magnetism but the orientation of the magnetic pole of the magnet will certainly have a profound effect on how well (or poorly) an electric motor will operate.
OEM magnets often get damaged or knocked loose when people react to human instinct to beat on offensive components with hammers/tools if they are not working correctly. Recalcitrant starters seem to get the lion's share of this type of attention.

So. are you saying I may have glued it in 180 degrees opposite?

It is still not working. I borrowed my neighbors battery, and even tried jumping mine off with my truck. It will initially spin over, but quickly starts dragging. The magnet is holding in place, but do you think putting the liquid nails between the magnet and the cylinder wall has affected anything?

I purchased a new starter (# 497595) at my local repair shop, but I have not installed it yet. I do notice a slight less resistance when spinning the shaft on the new one. There is a noticeable difference when I twist the clutch drive.

Thanks!

I'm simply saying that IF.....the magnet was installed 180 degrees out of its original OEM orientation, that magnet would cause an opposing force to the efforts of the other 3 magnets.
Or, to put it another way...3 magnets want to spin the rotor clockwise while 1 magnet wants to make it go counterclockwise.
Or maybe this analogy: 3 magnets want to go, go, go while 1 magnet says no, no, no.

Hmm, B&S starter has 2 magnets.

Walt Conner

I put the new starter in and all is well. Is my old starter junk, or can it be repaired?

Thanks for all the help guys!

After all you have been through????
Pitch it in the scrap!

I guess so. I just hate not being able to repair it.