what should my pistons look like?

I asked this question in another thread, but it got lost in my other blabbering.

My 1988 Johnson 140 will not stay running, and while I've been trying a couple things, I had another question:

With brand new plugs, I ran it at idle for 5-10 seconds until is stalled twice. Then looked into the cylinders with a flashlight. The top two were wet looking and rough... almost like black wet sandpaper. The bottomw two though were dry and black/gray looking... almost like faded black matte powdercoating.

A friend of mine says they should not look dry, and I might be lacking oil in the bottom two and really screwing things up by trying to crank it. The thing is, the bottom starboard plug is the one that came out really oily after running for just a couple seconds... sure dosent look dry to me.

any thoughts? Should I not try and turn it over if two of them look dry? does anybody have a picture of what I piston should look like after runing for a couple seconds? I couldnt get a pic to come out.

Thanks,
Eric

Re: what should my pistons look like?

this is like trying to figure out whats wrong with your car by looking up the tail pipe.

Do this logically.
State the problem and list the things you have done.

I had a mechanic work my engine over at my house last yr, I didn't know squat about it, but I watched and learned, we did quite a bit of troubleshooting, decarb ,checked carbs ( I rebuilt them) and worked the ignition over ( replaced P/P) but never did he look at the pistons thru a tiny hole.

Anyway, if it will not stay running its either losing spark or fuel.
A cheapo timing light will help there.
If plugs are wet its probably dropping the spark.
Examine coils very closely ( remove and turn over in your hands) look for cracks.

Re: what should my pistons look like?

I understand... I was just trying to make sure I wasent hurting it by trying to start it with dry cylinders or whatever... so I dont need to worry?

I have decarbed, thouroughly cleaned carbs, replaced fuel line, replaced plugs, ran on external tank, checked spark by holding against block (will check gap today).

One question... how will a timing light help to see if its loosing spark? I'm not familiar with using one, and have only rudimentary knowledge of its purpose.

Re: what should my pistons look like?

You want an inductive type timing light.
Put the inductive lead on one spark plug wire at a time. Look for consistant flashing. If there is a problem the flashes will be inconsistant.