Over 1,000 Posts
I'm not familiar with the 650 engine. Is the head a bolt on or will it require machine work?Was never able to get the 650 to run full power. Replaced the clutch, ran several ignitions, never figured it out. I literally hate not having a kickstarter and I would much rather run a smaller battery, so the plan I have come up with is to run a 550 bottom end which has a kick start, 650 pistons, bored 550 cylinders for 650 pistons, and a 650 head and cam with a 550 cam sprocket.
It's a common swap to machine the crown of CB750 pistons and machine down the skirts to get your size piston on the CB550. Not sure you have to do that anymore, as you have done. I assume you've heard of or read the "Gentleman's Express" article which refers to that process. CrazyPJ has a few posts out there about this, as well. The CB650 piston is 59.8mm.That’s interesting Irk, i’ve taken my 550 out to 61.5mm=600cc
never seen a sohc 650 let alone worked on one !
Honda used the same tooling to build the 650 engines, so everything is pretty much the same as far as castings. The 650 head is the better head, since it has shorter runners and it's ported. Honda put the last of their SOHC tech genius into that head. The rocker covers are different, but they match up to by bolt pattern. People tend to like the look of the 550 engine better, but I like the rubber gasket design of the 650 covers.I'm not familiar with the 650 engine. Is the head a bolt on or will it require machine work?