i checked the tapets on and they were all within spec so i decided to remove the cylinders and barrels to inspect them.

it turns out the previous owner has installed 1000cc barrels and pistons without any modifications. to make it worse he has filed down the tops of the pistons to prevent them hitting the heads.

it gets worse still, the pistons aren;t even the same. one has circlips which you take out using cirlclip pliers and the other has the ciclips you pry out with a screwdriver. the tops od the pistons also have a different shape.

i have decided to put the egine back to stock by buying some second hand 800cc pistons and barrels and then reset the carbs back to stock settings.

does anyone have any tips for checking the valve seats will i have the head off?

oil consumption was low and the bike blows no white smoke so i am guessing the valve guides are in good repair.

a friend suggested turning the heads upside down and filling them with petrol to see if they are sealing. if petrol leaks through them i need to regrind the seats. does this sound like a good tip?

while i am in there i am going to replace the rockers as they are showing signs of pitting, does any one know what year models have interchangable rockers with an 83 r80g/s to make buying a second hand set of rockers easier?