I have the bike running again now, although i have only slowly ridden up the driveway to test etc. I have put a 320 main jet in and have read plenty of posts now of which a lot say to use a 320 ish main and a 40 pilot for a cr480 or similar capacity bike, however one i read recommended a 380-390 main, which is way over what most others say... I am also replacing the reeds with a Boyesen set, as somebody in the states has played with the limiting plates, underbending the top centre plate and overbending the opposite lower centre plate, i presume to direct the fuel air towards the base of the barrel. I re-bent the plates back to standard, but will replace the unit at any rate. I also decked the top of the cylinder as the new liner was about 0.2mm below the top of the barrel, making it near impossible to clamp the head gasket correctly around the cylinder. i doubt this would have helped the head gasket at all !! The head was also re-surfaced to ensure it will seal correctly and i lightly sanded the standard combustion chamber to remove a few casting dags etc. As the barrel has been faced i used 2 base gaskets when re-asembled, and the piston clearance seems to be around 1mm to the squish area in the head. I never measured the diameter of the head chamber, but this motor is a whole 5mm larger in bore over stock, and i also wonder if a cr480 has a cylinder head with a larger combustion chamber dia to suit, as mine still appears to have the stock 450 head which may also affect running. The piston kit i think is wiseco and is 90.0mm. there is a" w" in an oval circle cast into the base of the piston if that helps. I am also about to replace the crank seals as when putting the motor together i found gear oil on the crank weights when rotating the crank, so this also would not help matters, especially if the other side is leaking air into the crank... although all said, when i can actually manage to get it to kick over TDC ( i am only 65kgs and this beast has heaps of compression)it usually fires first kick and runs very sweet, and pulls very hard and clean. I was amazed really at how well it runs for an old bike, nothing like i was expecting from all the reports of the day, although it is a long way from a 431cc now! The bike looks like it has sat in a frozen barn for a good 20ish years, even the tyres have cold cracks and havent been in production since the 1980's so the local dealer says. I will look into posting some pics, i presume i have to host pics on a free site and link them back to this site. Thanks for your help, regards Pete.
