Mg midget 1275 engine no compression on cylinder 3

[bluegrass]

I recently bought a 1275 midget engine which was meant to come from a running car.
Today i tested the compressions out of the car using the starter motor, sparks out. (I did put a little oil down the spark plug holes and turned over by hand to make sure all was free before hand.)

I got the following:
Cylinder 1 :225
Cylinder 2: 175
Cylinder 3: nothing
Cylinder 4:170

I put some more oil down the cylinder 3 bore and got 150 or so.

After i took the head off, all the bores looked very good, and cylinder 3 held oil fine.

The head itself seemed very coked up around the valve seats, (as did the tops of the pistons)
The exhaust valve from cylinder 3 had some damage at the top (spring side) so i could not pull it through the valve guide, though it moved fine upto that point.

The other thing is that both the cylinder 3 valves looked dry compared to the others.

Any thoughts as to what could be the problem much appreciated. Pictures below.[frame][/frame][frame][/frame][frame][/frame][frame][/frame][frame][/frame]

[bmcecosse]

Since adding more oil 'fixed' it - either the rings were all stuck 'in' (which is a bit unlikely that they would ALL be like that) or perhaps that valve was stuck open - more likely I think. Anyway - it's going to need the pistons out for inspection (and a look at the big-ends and the centre Main shells ) - and a complete head overhaul.. At least you now have an 'old' valve....

[bluegrass]

Thanks for that, much appreciated.....especially the 'old valve ' comment..... . I should also have mentioned that i'm hoping to put this particular head onto my 1098, and the big valve head from my earlier post onto this 1275 engine provided it checks out ok. I might as well sink the exhaust valves on this 'standard' 940 midget head whilst servicing it ready for when it goes on the 1098. I'll report back on the pistons etc once I get them out.