piston number 1

[highland morris]

I have taken the head off my 1098 cc engine and all the piston on top are clean except number1 it had a bit of what id describe as burnt thick oil on it what does this mean

[MarkyB]

It could mean several things, broken rings and knackered valve guides/seals are the first that spring to mind.
You might get something similar if that cylinder wasn't running properly for some other reason.
Why did you take the head off?

[highland morris]

basically the engine was running ok but I bought a rebuilt replacement as mine was bit smokey seiing as new engine is fitted and running sweet and the old one was lying in the shed I thought id check it and mabe . rebuild it for a good spare I suspect the head needs set of valves guides etc the bottom half is still in one piece . so was going to replace all gaskets repaint etc .but seeing as its not got head on . ill check everything before rebuild and spruce up hence clean every thing . that's when I noticed that number 1 piston was allitle sooted on top rest are clean just passing time lol. also must mention im no mechanic so just going by pics etc this will be my first engine ive done

[bmcecosse]

Most likely broken rings - or piston damage - may as well pull that piston out and inspect it.

[highland morris]

would u recommend replace all rings main shells how can I tell if the crank shaft is ok thanks for all help

[bmcecosse]

You need to open it up and inspect the crank journals....and the condition of the shells. Post up pics..... What was the reason for taking that engine out - was the oil pressure low? Bearings rattling? Burning oil? Down on power?