7024 "bricktop" off switch (knob) not working right

[lawnboywillneverdie]

what i have noticed is that once i turn the knob to off it sputters but then keeps going. but if i slowly turn it back to on, there is a spot where it will turn off at. I have lightly sanded both the screw it touches and the metal "thing" that grounds it to turn it off. still hasn't had a "normal" shutoff. Any suggestions on what to clean as i know that its a matter of finding a corroded point or something but dont know where to start. Any suggestions?
if you want a pic of it i will get a close up of the (don't even know how to describe it without looking stupid ) metal point that turn it off.
Don't make fun of how i described the off switch as i dont know what to call it.:mur::ashamed:

 

[dewguy1999]

I'm not familiar with the particular switch that your Lawn-Boy has but I'd say that from the sound it, it's probably just worn out from being used for the last 30-40 years.

 

[Phototone]

The on-off switch is also part of the primer. Unless you have the "choke" style carb. On the "choke" style carb the flat body of the on-off rod presses against a spring when you turn the mower off, and it grounds out the coil. On the Primer type (push down to prime-style) there is a spring and a metal tab on the bottom of the primer rod, that the metal shroud of the mower holds in place. Spring pressure allows for grounding out against a screw that holds a shorting wire from the coil. Perhaps your spring is not "springy" enough to push down well.

LOOKED at your photo..you have the primer style, which is a plastic rod, spring and metal tab on bottom. Held in place by the shroud of the mower.

 

[robinb66]

What you need to do is pull the shroud off, look at the base of the primer rod/ kill switch rod and look at the little teardrop shaped piece of metal because it sounds to me like its got rust on it where the kill plate meets the screw with the grounding wire, witch is very common on these lawnmowers but an easy fix, just remove the rod and the metal piece and sand the rust off of it and the kill wire screw, because it sounds to me its not making good contact!!