Hello, I am probally wrong but i havent seen or read about any silver engine 325 beamish bikes. The only 325s i have seen had the black engine which was supposed to have been made as a 325 .{ 250 black engines are fitted with an extra liner bringing them down to 250cc and some differance on cyl. heads to get correct compression ratio} I think several people have converted a black engine 250 to a 325 by removing the liner , new piston & altering compression with machining or extra gaskets.
The black & silver engine 250s have same bore & stroke 70x64 .The 325 is 80x64 so only differance is bore size wouldnt think crank or con rod are any differant.
Anyway i expect you allready know all this , i think there is a thread on this subject on the Trialscentral forum somewhere.
if i find any more info i will put it on here
dave
