spark plug life

[Peter]

My lawnmower won't start again. It is a four stroke Honda, the fuel supply is OK, the spark looks OK when I take the plug out and rest it against the cylinder head and pull the cord. However, I know from experience, that as soon as I go down and buy a new spark plug, the mower will work again. The plug seems to need renewal, even though I have a small lawn, and it would have done no more than 10 hours work, maximum.

What life do others get out of their plugs? Could I be missing something? Ta Pete

[Anthony Diodati]

[Tony Hwang]

[Des Perado]

I have a LARGE lawn and live in the Pacific Northwest where the ample rain makes the grass grow like mad. I think I last replaced my lawnmower spark plug 3 years ago. I check it each Spring and clean it up a little. The mower starts first time, every time. Des

[TURTLE]

This is Turtle.

I have been down that road a bunch and the only thing that was told to me by a small engine repair fellow on this was : A small engine will flood out or get the spark plugs soaked in gas and or oil for a while and it does something to the white part , I guess ceramic stuff and it will not hold back the electricity and just not make it fire at the points. The gas will kill the insulating propertys and make it not fire right. So just change the plug every year and live long and prosper.

TURTLE

[George E. Cawthon]

[Peter]

Yes, Tony, plug clean and regapped. Pete

[Tony Hwang]

[Joe Bobst]

Turtle is absolutely correct, as all pro mechanics know. If the condition is endemic in any engine, the solution is to match the spark plug heat range to the engine operating conditions. First option, try a hotter plug (use the manufacturers charts). Next option, use better air filters. Cheap ones tend to make engines run too rich and foul the plugs. HTH

Joe

[zxcvbob]

You're supposed to change those things?

Best regards, Bob

[Iowa883]

I have a Rumely Oil Pull tractor that was made in 1927 . It is ran ever yera in 90+ degree temps. It is finally on it 2nd pair of plugs as of 2 years ago. So, either they don't make them like they used to (probably the case) or you have something else wrong. Iowa883

[Jerry G.]

If the lawnmower is sitting all winter without being used, the spark plug may gum up. You can try to clean its contacts with some crocus cloth of a medium find grade. I would prefer to change the plug every season, for reliability.

If the spark plug is getting gummed up during the times of use, then you have a problem with the motor. It is possible that it is not burning the fuel properly, due to bad rings or seals, or you are using low grad fuel in it. This means a motor rebuild.

[Tom Bach]

What colour is the tip area of the plug? If it's sooty then the mixture could be too rich. Is the exhaust smoky when it's running? Starting could be difficult if you are trying first thing in the morning when the mower is covered in dew. Do you have better luck if the mower sits in the sun until it's good and hot throughout?

[Bob]

I've used mowers for more than 10 years on large lawns without changing plugs.

Bob

[alt-hvac Moderated]

It's been my experience t hat Champion lawn mower plugs don't work well, and don't last very long. NGK and Autolite work well. Try a different brand.