Small Engines (Lawn Mowers, etc.): Engine turnover issue, murray tractors, hp 40

Question
Hi David
This question may be an insult to your qualifications; seems a little petty based on your vast experience so I'll understand if you defer.
Have a Murray riding mower 12.5 hp/40” cut, model 40631A, purchased 2/92. B & S engine, model 286707, type 0115 01.
For past couple of years, when I start it, I have to release the clutch/brake pedal about ½ to 1 inch for engine to turnover and start. Always starts right up when I do this. But originally, I just pushed the clutch/brake pedal all the way down for it to start. Now, when I release the pedal slightly it always starts, I just have to push & release the pedal to FIND the “engage point”. But I figure one day it just won’t start so I want to be prepared as to how to fix it. I’ve looked in owners manual but it doesn’t address this problem. When it doesn’t engage, it doesn’t make any noises, no clicking sounds, etc. It’s like a dead battery until I hit the right spot and it starts right up. Do you know what might cause this and how to fix so I don’t’ have to “search” for the “engage point” when I turn the key? Also, how long can the engines on riding mowers last if you drain oil and empty the gas tank at end of every cutting season. Install new air filter, plug, gas filter, blades each season when ready to use again. I’ve replaced some parts over the years but no engine parts except spark plug.  Never been to a repair shop. Have always kept eye on oil level to make sure it’s good. I’ve been surprised it’s lasted this long so just wondering.  Thanks so much, Don

Answer
Don,

This is a common problem with the older Murray Tractors.  The Clutch/Brake safety switch simply needs to be adjusted.  Loosen the two screws that hold the switch to the tractor frame and move the switch forward until you achieve that "engage point"

If the holes are worn excessively which they sometimes do...simply replace the switch with a new switch.

Sometimes if you remove the switch and clean it good with an electric parts cleaner/spray this will temporarily help the problem too.

Thanks for the question...