Trouble starting

[banksy]

Hi guys having some trouble with my 2002 CBR 929
It has full service history including a 16000 miler about a year ago.

Basically it was running fine and then sunday morning I tried to start it and it just cranked over, didnt fire up. I didnt know what it was so just to try it I put my hand over the exhaust (to simulate a baffle?) leaving a small gap and it started. That worked times on sunday and yesterday although if it was still warm it didnt really need it.

Today I tried starting and still cranked over. I tried the hand thing and still it didnt work. I tried putting the real baffle on and that didnt work either. Now Im wondering what could cause this. I am quite technically minded and have tools so I dont mind checking things but not sure what I should check?

The battery is not great but I charge it every night and it generally works fine.

Please help as its my only transport.
____________________
banksy
-CG125 07- -GS500F 04- -CBR600 98- -FJ1200 86- -XT350 91- -CBR900RR 01-

[banksy]

ok thanks, will check this
just to confirm the head gasket is the rubber seal between the top section and the rest of the engine?

I took the plugs out the other day, cleaned them and put them back. There was a bit (not much) of oil on the sides of the plugs. The plug heads themselves were not oily.
The bike worked after this but now (after a couple of days) it's starting to do it again. Again no problem if its warm, mainly overnight it happens.

Also the oil level is above the sight glass, thats very bad, isnt it!?

If its not the head gasket, could it be loosing compression through the spark plug holes? Possibly they are not in tight enough or are being pushed out by the oil pressure too high??
____________________
banksy
-CG125 07- -GS500F 04- -CBR600 98- -FJ1200 86- -XT350 91- -CBR900RR 01-