350 Safe Running Tach RPM’s

[Stoneman]

I can’t find any info on safe RPMs on the 350, or any info on what the redish colored area of the tach represents. And the RPM readouts beyond this area of the tach go way beyond RPMs in the red area. I’ve run my 350 up to 6000 which is where the red area starts (if I remember correctly), but is it okay to push on beyond this? Maybe the colored area is simply the comfortable running RPM? Guidance here will be greatly appreciated.

Thanks,
Steve

[BRT-GTR]

       Taken from the manual, max torque is developed at 7000rpm and max power (37 or 40hp) is developed at 7500rpm, so yes it is safe to take the engine to 8000 rpm assuming she is fully run in.
            However, one adavntage of a disc valve engine is they provide good torque at lower rpms so unless you are having a bit of fun or want to reduce your engine life, I wouldn't recommend using max revs all the time, lol.
      The max power was originally quoted as 37hp but sometime later this was upped to 40hp with no changes to the engine that I am aware of ! Max power was everthing in the late 60s when it came to sales. Kawasaki had the contempory (67-71) 350, A7, Avenger which claimed 40hp and was later increased to 42hp with bigger carbs. Suzuki had the 315, Rebel in 1969 with claimed 39hp. So I guess Bridgetsone suddenly found the GTR could produce another 3hp !!, although I am sure a good GTR could produce 40hp+.  Even Richard Clarke commented once that some 350 stones were noticeably better than others.
     Why was this ?, anyone any thoughts. Piston clearances, crank seals, carb or ignition settings?

[Stoneman]

Thanks for that information; very helpful.  You mention manual— I have a copy of shop manual but did not see any reference, per se, although rpms could be determined in the torque curve diagrams. But it doesn’t give any indication as to whether those rpms are safe to run. With universal electric motors (as opposed to induction motors) the highest torque is achieved just before the motor destroys itself.

And is there an owners’ manual for the 350 available to download? Would like to have a copy.

Steve

[Stoneman]

Just dug a bit deeper and found the owners’ manual in the download section. Answered a number of questions I have had. Wish I’d found it earlier. Oh, well.

[Stoneman]

Just dug a bit deeper and found the owners’ manual in the download section. Answered a number of questions I have had. Wish I’d found it earlier. Oh, well.