Cracked spark plug

[tacklejunkie]

Changed the plugs in my riding lawnmower and it  was cracked, runs perfect now but any idea why it would crack?

[rundrave]

what color is the plug? can you tell if its running rich or lean?

 

Or maybe it was just bad and a defect? How did it run with the old cracked plug in?

[tacklejunkie]

28 minutes ago, rundrave said:

what color is the plug? can you tell if its running rich or lean?

 

Or maybe it was just bad and a defect? How did it run with the old cracked plug in?

 

 I just put non-oxygenated fuel in it but it was pretty dirty. 

 It started and ran OK it would just miss at idle.  It runs good now I’m just wondering if there’s something  underlying that could be causing the crack 

[Mike89]

it could just be a bad plug...  

[bobbymalone]

How long was the plug in?

 

If it was there for a long time, I wouldn't worry about it too much.

 

They can break if they get super hot.  Like something wrong with your engine super hot.  

 

You can also crack them with over torque, but that should happen not too long after putting them in.

Edited July 18, 2020 by bobbymalone

[tacklejunkie]

12 hours ago, bobbymalone said:

How long was the plug in?

 

If it was there for a long time, I wouldn't worry about it too much.

 

They can break if they get super hot.  Like something wrong with your engine super hot.  

 

You can also crack them with over torque, but that should happen not too long after putting them in.

 

 They were three years old

[bobbymalone]

I am guessing you mean the porcelain when you say it cracked.  Was it the part inside the cylinder at the electrode or the part where the boot slides over.

 

I'm thinking this is probably not something I would worry about unless it happens again.

[tacklejunkie]

On 7/18/2020 at 10:40 AM, bobbymalone said:

I am guessing you mean the porcelain when you say it cracked.  Was it the part inside the cylinder at the electrode or the part where the boot slides over.

 

I'm thinking this is probably not something I would worry about unless it happens again.

 

it was the porcelain