Author Topic: CB750 K3 - lack of power  (Read 1837 times)

Offline garyjpaterson

  • Newbie
  • Posts: 29
    • View Profile
Re: CB750 K3 - lack of power
« Reply #30 on: August 21, 2023, 09:37:57 AM »
Speedo cable is new, since the bike didn't come with one. And it does oscillate a little, but not much, about what I'd expect for this age. My CB350 is really wild, at speed it can swing around to quite the extreme! But tbh I'm not overly concerned about the speedo, just knowing its off and by how much is good enough for me for now.

Interestingly, cyl 4 compression is fine, at 150psi. But cyl 1 is a bit lower, at 130psi, yet that plug is in line with 2 and 3. I'll be testing compression on them all again once ive got more miles on it.
I'll probably end up with the carbs off again just to absolutely make sure the idle circuit is totally clear, floats are definitely correct etc
« Last Edit: August 21, 2023, 09:40:30 AM by garyjpaterson »
'73 Honda CB750 K3
'71 Honda CB350 K3 twin
'00 Honda ST1100 Pan Euro
'89 Yamaha XT225
'02 Suzuki GSXR600
2x '71 Suzuki T250's in pieces... maybe they'll make one eventually

Offline Spitfire

  • SOHC Master
  • Posts: 1777
    • View Profile
Re: CB750 K3 - lack of power
« Reply #31 on: August 21, 2023, 09:52:22 AM »
When I rebuilt my 750F1 I followed my wife in the car through Liverpool and was gobsmacked at the speeds she was doing through the camera infested areas, so I did some testing using the car as a pace maker, at 30, 40, 50 and 60 mph.
 The result was the speedo on the Honda was 7 mph fast at all speeds, no wonder I was having problems with 30 mph speed limits, so since then I just deduct 7 mph from whatever it tells me.

Cheers

Dennis
1976 CB750F

1977 CB750F2 In bits

1964 BSA A65R In bits

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal