Topic: 1974 cb750 whine from engine

[D DIAMOND]

my 1974 cb750 starts to whine loudly from about 2000rpm onwards through all gears when I shut off on over run it is gone it is okay when in neutral and on tick over and revving in neutral thanks DD

[D DIAMOND]

have tried it no stand in all gears no whining noise DD

[PeWe]

My bike has a wining around 4800 rpm. I think it is the 4-4 that sings due to resonance of the typical inline 4 vibrations around this rpm.
I found one loose bolt keeping the exhaust spigot for #3. Tightened it and much better. It sounded like no oil on cam or cam chain tensioner running dry.

Speedometer or tacho can make bad sound too. Possibe to remove it, upside down and spray some oil inside the cable connection to lube the gear. Let it rest for a few hours still upside down. This fixed my old screaming speedo.

[D DIAMOND]

thanks for your reply I have had this exhaust system on one of my other bikes and it made a similar sound more of a drone in my ears the exhausts are replica seconds will try a genuine set off one of the others DD