1973 cb450 – Part 2
So… after taking the engine apart it was apparent that we couldn’t diagnose the cylinder head properly. The cb450 in the 70’s has a really weird cylinder head design. Instead of having valve springs, it has what are called “torsion bars” which hit the valve to open it, and also, hit the valve to shut it. Really weird…
Also, each piston has 3 rings on it… bottom is oil ring, and top 2 are compression rings. So… the middle ring on each piston was “stuck”. Meaning that it didn’t have any free play in it.
So… I took the cylinder head to a specialty engine machine shop here in the N.E. philly, and explained the rings. They told me that a ring should never be stuck like that, and that’s why oil is burning. Also, they told me not to fuck with the cylinder head. So, I took their advice, didn’t fuck with the head. Ordered new OEM pistons and rings.
We re-assembled the engine on a tuesday night. Then put the engine back into the frame on saturday.
After several kicks, it fired right up and runs awesome. No more smoking. Did the timing and points. Rode it around fairmount park for a bit on sunday. It runs awesome!!!
I’m psyched. Successfully did our first real engine work.
Published - Mar 17, 2016
Some of you might be surprised to know that Ed leads a second life pretending to be a younger man. This young man goes by the name ‘chin on the tank-ed’. Not all that original in my opinion. Anyway, in this life I imagine he rides an eco friendly scooter, obeys the speed limit, drinks […]