How often should I change spark plug on my mower
WELCOME to LMF....
Your title is Oil... but then you ask about changing spark plug??
So I'll guess you meant to ask about both...
If you use a good Synthetic oil you could change Once a Year, or every 100 hours, whatever comes first....
And the spark plug should be changed, when it
Needs changing... I have a Cub Cadet with a spark plug that has been in it for Over 30 years... I remove and check the gap every Other year...
I have other small engines with their Original plugs, and they are all over 5 years, most over 10 years old... if the electrodes are gaped correct, and they are still working, Why would you think about changing them?? :smile:KennyV