Lawnmower Engine Starting Tips??

[Jay H 237]

Originally Posted by sanddrag

If I buy a new Briggs lawnmower spark plug, will it come already gapped or will I have to do that?

Most likely you will get a Champion or a competitor to Champion since Briggs doesn't make thier own spark plugs that I know of.

Some plugs do come pregapped but I would still check it. You never know if it got knocked around in shipping or what not but there's a possibility that the gap could've closed up or that it was never set correctly to begin with. You can get a good feeler gauge for under $10 and it's worth it.

If the gap is closed more than it should be the motor will still run but you won't have as much power. It will start up and run but it won't be making as much power and torque as it could, and at worst case, as soon as you start putting it under load it will stall out. It would be like trying to compete in a match with your robot while it has a half dead battery.

Of course if the gap is totally closed the engine will never start or run because there won't be any spark to ignite the compressed mixture. Same is true if it's too wide, since the spark won't be able to jump the wider gap.