Small (Non boat) Engine Question

[dutchman2858]

Working on a 3 HP Craftsman Lawn Edger. When I removed the spark plug, I pulled the engine through and what I thought was the top of the piston didn't move. No problem pulling it through, but it occurred to me that I haven't looked down through the spark plug hole on a single cylinder 4 stroke engine in a LONG time, so don't have a clue whether I was looking at the piston or not. I DO know that if it's the piston, it should be moving!

So the question is: am I seeing the top of the piston, or is there some sort of baffle (?) blocking the view of the piston? Fall back position is to pull the head, but will avoid that step if possible. Thanks.

[Bodofish]

Looking through the plug hole you should only be seeing piston. If it's not moving, something is broken, in a major way.

[dutchman2858]

Thanks, Bodo....well got 2 yrs out of my CraigsList bargain(?) anyway! Time to pull the head just for the education...On second thought, I think I'll go fishing for now :-)

[Bodofish]

Thanks, Bodo....well got 2 yrs out of my CraigsList bargain(?) anyway! Time to pull the head just for the education...On second thought, I think I'll go fishing for now :-)

That's what I'd do! Sounds like a winning plan! Don't fix broken engines, just get a new predator from HF. Excellent running engines.
OR a new CL mower!

[dutchman2858]

OK, quick update. I pulled the plug again and peered in the hole with a flashlight. Off to one edge of the hole was a valve opening and closing, and far off to the other side I could see the piston doing its up and down routine. The design of the engine is such that it wasn't easy to observe the piston through the spark plug hole. Looks like I'm good to go with that issue!
But I'm still going fishing

[Bodofish]

OK, quick update. I pulled the plug again and peered in the hole with a flashlight. Off to one edge of the hole was a valve opening and closing, and far off to the other side I could see the piston doing its up and down routine. The design of the engine is such that it wasn't easy to observe the piston through the spark plug hole. Looks like I'm good to go with that issue!
But I'm still going fishing

Hahahaha! Perfect!!!!!

[Sideburns]

most small engines like that are still old flat head engines. The valves are upside down and the spark plug is offset from the piston. Sounds like you figured that out already though.