whats caused this?

[roach3]

bought my lc2 2 years ago and after stripping down noticed the powervalves were sloppy with play in all directions

so picked up a decent set of valves and fitted new bushes castles and orings .

bushes were from legend and to be honest the were a very tight fit but got them in eventually.

after torqueing everything down I noticed the valves wouldn't spin freely and had tight spots, I put this down to me securing barrels first then head which slightly offset the valves.

so re did them by torqueing head first then barrels second, this cured the sticking valves on assembly.

or so I thought, after a few hundred miles or so I noticed oil leaking from the centre of the valves and the left hand side aswell.

so decided that seeing as I will be stripping the bike again for other jobs ill rebuild the top end with new gen yam valves bushes etc.

100 mil or so later the valves jammed stopping the bike from revving past 5500rpm I was 60 miles from home and rode back taking it easy.

parked bike up bout a month ago till today and stripped top end down and found to my horror this!!

the left hand piston has two small pieces missing that have welded themselves to the head.

could the 60 mile ride home with jammed valves have caused this?

im guessing ill need a rebore and new pistons etc also will I need a new head aswell

many thanks

Charlie

[muttsnuts]

that looks like that has been caused by a ring peg getting loose from the piston and hitting the piston and head, since you are taking the barrels off check the piston ring grooves to make sure both pins are intact, if they are then the foreign body has come from elsewhere.

Its possible whatever has caused that damage has jammed you PV as well, so check for it lodged in the PV's or barrel

With respect to the head and bores, the head will run again as is, just clean up any shape or protruding edges from those areas damaged, your bores will be fine unless there are grooves in them, take some piccies and post up if you aren't sure

[roach3]

thnx for reply mutts

although it looks like holes the damage to the head is actually the two bit of piston missing from the piston crown welded to the head

the bores look undamaged to my eyes at least but ill post pics

ive caught this early coz im fitting new p valves bushes seals etc

the bike was actually running ok apart from the sticking valves

so its a rebore , new pistons and I can pick out the pieces of the head and smooth it out?

cheerz

charlie