To -Mully - I do not have an answer for your question... ----- To -BSA - yes -- whenever possible (always) use a new head gaskets when putting a head back on. In the (very) old days -- sometimes my grandfather would reuse the same head gasket -- but, he also hardly had enough money to buy food.. Grandpa rode a BSA 500cc one lunger in those days -- nice old motorcycle.. Happy Riding from - Mountainman
just measure the thickness wit a pair of calipers, then check with sheet metal/roofing contractor .if they don't have the right gauge, they can steer you toward where to purchase it. but beware copper is bringing $4.00 per pound for scrap here. so get ready to dig deep if you buy it new. maybe you'll get lucky & find a peice or two from a contractor.
In what way is copper better than aluminum? Seems like the aluminum gasket works fine - IF you retorque it about 3 or 4 times from new.
Some this idiot (ME) forgot to do this yesterday before a long ride. After installing a new head gasket after lapping the head last week, I forgot to retorque it when it was cold. On the way home my bike was down on power, going all funky noise time at high RPM, generally just limping by the time I made it to me street - acorn nuts were just about LOOSE!!.
Does copper and or sealant help with this retorque regime?
I just made a new head gasket for mine. It was supposed to be .032 thick but they gave me a piece of .019 so i used that. when you take the head off get a dremel and smooth out the defects carefully. I also polished up the head chamber as it helps keep carbon down. The other things i did was to carefully grind a small chamfer where the chamber meets the gasket so as to create a simple squish band which forces the air fuel mixture in a concentrated area which helps with torque and power efficiency. It also is a bit of a safety margin to stay away from the piston as i was to lazy to plasticine the pistion and head for clearance. The stock thickness was .057. Just got back from a 45 km or 28 mile ride 3/4 throttle on a 44t with an 70 cc happytime as a test run and it made a noticeable difference on the hills and take off, definitely more bottom end. I use copper because it can be reannealed indefinitely and reused over and over.