i dont visit here much but i thought this might be the best place to ask,ive searched through all the gentlemans express threads but im still left unclear as to what i have,,its a 550 barrel bored to 61mm,it was assembled by a chimpanzee at some point i think,the pistons wont make it into the bores under gravity,although it was forced together without rings,a few remnants in grooves and one or two half bits of ring in the bottom end,,and some frags embedded in the barrel and case gasket area!,i think ill be able to rescue this top end unit though,the 61mm piston is .65mm taller after the wristpin than a 550 piston,i can see the slightest valve touch on the crown marks,,whats the common method of using 750 pistons in this set up?do you buzz that .65mm off the top(too easy),the longer skirt hasnt fouled the crank,i think someone put this together and it was just bad or something???,there dosent seem to be much wear on the pistons but they had the brown from use look underneath.some photos.
piston on the left is brand new .25mm oversize 550,i get .65mm here.
even the smallest piston wont drop through
no marks show the front
bk in a circle
"cs" with the s inside the c