Author Topic: '72 carbs on '78 engine?  (Read 614 times)

0 Members and 1 Guest are viewing this topic.

Offline ECinCLE

  • Full Member
  • *
  • Posts: 12
'72 carbs on '78 engine?
« on: March 01, 2017, 03:37:30 PM »
Hi guys,

I'm re-building a '78 CB750 engine for my hardtail.
See my other post in Projects (http://forums.sohc4.net/index.php/topic,164118.0.html)

Ive found a really good deal on a set of '72 carbs. Anyone ever put these on a '78? Will it work? I'm assuming different manifolds and jets......

Any help is great!

Thanks,

Offline BPellerine

  • Master
  • *****
  • Posts: 2,222
Re: '72 carbs on '78 engine?
« Reply #1 on: March 01, 2017, 05:36:44 PM »
yes they will fit ,you have to use the pre 77 carb rubbers,the 77/78 will not fit,use cables for the early carbs too.bill
1978 CB 750K ard and webers
another anfob

Offline ECinCLE

  • Full Member
  • *
  • Posts: 12
Re: '72 carbs on '78 engine?
« Reply #2 on: March 01, 2017, 11:20:50 PM »
yes they will fit ,you have to use the pre 77 carb rubbers,the 77/78 will not fit,use cables for the early carbs too.bill

Hey Bill,

Thanks for the quick reply. I'm sorry I'm not really a sure what you mean by 'cables' for the early carbs.

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: '72 carbs on '78 engine?
« Reply #3 on: March 02, 2017, 09:39:52 AM »
Push pull throttle cables.
Start with '72 carb jetting, and adjust from there based on your intake/exhaust.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mineā€¦"