G2460 fouling #3 plug

[TheOldHokie]

As the subject line says my G2460 mower started fouing #3 plug - looks like its oil, Replace the plug and it runs great for a few minutes then fouls again. Starts easily with or without the fouled plug. Anybody had this problem and was it as simple as a bad valve stem seal? I am not in a position to do any major engine work. May try some cylinder lube on the off chance its a stuck ring.

Dan

 

[RCW]

Dan - a new plug fouls in a few minutes’ run-time, but it otherwise starts and runs okay?

 

[TheOldHokie]

Dan - a new plug fouls in a few minutes’ run-time, but it otherwise starts and runs okay?

The new plug fouls after a few minutes of rum time. Once it fouls the engine runs rough and loses power but will start with a.few extra cranks.

Interestingly I just started it after it sat for 3 months with a fouled plug while I was recovering from surgery. It appeared the fouled plug cleared after a few seconds of rough running and it started running like a top. Did not have time to investigate further but it started me to thinking about stuck rings....

Dan

 

[RCW]

Got it. Certainly a little “mystery oil” of your choosing won’t hurt anything.

Nothing ventured nothing gained.

Maybe one of the more experienced guys will have some ideas.

 

[TheOldHokie]

Got it. Certainly a little “mystery oil” your choosing won’t hurt anything.

Nothing ventured nothing gained.

Maybe one of the more experienced guys will have some ideas.

I cant help but think about a 1965 Olds F85 I had in college (1973). It was oil fouling plugs and I assumed it was bad rings. I spent several weeks taking the engine apart on the street in front of my apartment. Turns out the rings were fine and the problem was nothing more than valve stem seals that had hardened and fallen apart. A local garage could have replaced them in a day and for less than I spent on DIY parts.....

Dan

 

[RCW]

I had the valve seals done on a 1967 Chevy Caprice…..

 

[North Idaho Wolfman]

I cant help but think about a 1965 Olds F85 I had in college (1973). It was oil fouling plugs and I assumed it was bad rings. I spent several weeks taking the engine apart on the street in front of my apartment. Turns out the rings were fine and the problem was nothing more than valve stem seals that had hardened and fallen apart. A local garage could have replaced them in a day and for less than I spent on DIY parts.....

Dan

When my 65 F85 cutlass started smoking I replaced the 330 and 2 speed powerglide, with a Hurst Olds 750hp 495 and 2500 stall Turbo 400.
The only thing that smoked after that were the tires.

On your plug issue have you checked spark quality while running?
A bad coil / wire will also randomly foul a plug.

 

[TheOldHokie]

When my 65 F85 cutlass started smoking I replaced the 330 and 2 speed powerglide, with a Hurst Olds 750hp 495 and 2500 stall Turbo 400.
The only thing that smoked after that were the tires.

On your plug issue have you checked spark quality while running?
A bad coil / wire will also randomly foul a plug.

I had not considered the coil. I will keep that in mind but the fouled plug(s) look pretty oily. Think I could stuff a 495 in the lawn tractor

Dan

 

[lugbolt]

a few minutes?

It takes a lot longer than that to foul a plug even if it's smoking and burning a quart an hour; or it "should" take a lot longer--assuming the spark plug is new, and the spark energy is sufficient. A plug wire will certainly cause your complaint; been through that on a 2.3 ford. Bad high tension lead, would foul only #2 plug because that plug wasn't getting enough energy to keep itself clean.

make sure to look at your valve clearance too. Probably ok but worth looking at.

 

[North Idaho Wolfman]

I had not considered the coil. I will keep that in mind but the fouled plug(s) look pretty oily. Think I could stuff a 495 in the lawn tractor

Dan

With a big enough pry bar anything is possible!

 

[Chanceywd]

When my 65 F85 cutlass started smoking I replaced the 330 and 2 speed powerglide, with a Hurst Olds 750hp 495 and 2500 stall Turbo 400.
The only thing that smoked after that were the tires.

On your plug issue have you checked spark quality while running?
A bad coil / wire will also randomly foul a plug.

Those F85's were a great looking/running car IMO! I remember my older brother having one with a 4 speed and probably that smaller v8. I was a year or 2 from having a license and wanted one of those but never had one.
I wound up with a 64 rambler American with a 196.6 straight 6 and 3 on the tree!
I would take one of them again in a heartbeat!

Bill

 

[GreensvilleJay]

A bad spark plug wire or distributor cap can foul a plug.

 

[lmichael]

I can't imagine a plug fouling that quickly. Maybe a compression test, without then with slightly wetted cylinder with a touch of oil to see if it changes. If it's really low and a touch of oil distributed in there brings it up then yeah I'd be thinking stuck or bad ring(s). If it's stable either way then maybe through the valve stem(s).
IDK what the ignition system is like on those. But it's another place I would be checking

 

[TheOldHokie]

I can't imagine a plug fouling that quickly.

I am not imagining. I am reportimg facts on the ground. A new plug will foul and engine will start running rough again in 15-20 minutes.

Dan