Classic Bike Values

Nope, the TX 500 definitely had 4 valves per cylinder John. I had one and
it certainly had 4 per cyclider when I had to disassemble it to get some
metal welded back in between the exhaust valves.

Al

 

From http://www.yamaha-motor.com/sport/epic_mcy/1973_tx-500_small.aspx

TX-500
"Yamaha broke into new territory by creating a 4-valve per cylinder
engine in a production streetbike with the 500cc, 4-stroke, twin cylinder
TX500."

Al

 

Alan I was referring to the CB450, I was aware of the TX500's problem with
cracking heads, at the time I was working in a Brisbane Motorcycle
Dealership (Cycle World) and regularly had lunch with the workshop staff
discussing such matters.

Boxer

 

Beaudesert Rd or the gabba shop ?

 

The one on Logan Road at the Gabba. It was a Honda dealership at the time
owned by Fred Drake.

Boxer

 

I even bought one in 1973.

Theo

 

Nah, mine would rev to 11,500 before valve float set in.

Theo

 

I bought one second-hand in '75, and got one of the few that didn't have
a weeping head gasket problem.