[CB350NZ]

With 50 year old valve springs and 44 plus thousand miles on the clock I think I would be a little conservative concerning running at extra high rpms.

Engine has had full rebuild

 

[CB350NZ]

Most likely skinny cam. Full rebuild .... like in a blue printed engine? Hope you improved the oil pump and put in roller bearings for the cam if you want to live at max rpm's. Last 350 engine I saw that may be able to handle it had close to 6000 dollars invested in it. Basically the www.cappellinimoto.it catalogue.
Don't get me wrong I push the red line and ride my bike like I stole it quite often. Best place to play is around the intersection of the torque and hp curves as shown in the link.

Horsepower and Torque curve for 1968 Honda CB350 offered since April 1968

Engine horsepower and torque curve for Honda CB350 in 1968, the model with standard body and 325.6 cm3 / 19.9 cui, 26.5 kW / 36 PS / 36 hp (net) offered since April 1968..

www.motorbikecatalog.com

Maybe I’ll change the terminology to reconditioned rather than rebuilt then…

okay so based off those curves sit at the intersection of 7,000rpm? The thing is though is it pulls so much better past 7,000rpm. Based off those curves the redline would be 11,000rpm?

I’m not asking what the redline is so I can get to it and sit on it, I’m trying to figure out where I shouldn’t go.