« previous next »
Pages: [1]   Go Down

Author Topic: 1976 750F jet compatibility  (Read 1334 times)

0 Members and 1 Guest are viewing this topic.

Offline johans

  • Enthusiast
  • **
  • Posts: 193
    • corporate leather
1976 750F jet compatibility
« on: November 30, 2018, 10:43:04 AM »
I have a 76 750F SS w/ 064A carbs that were jetted to 118 mains by the previous owner. After a complete rebuild it is running rich ( blackish exhaust )  . I have the CognitoMoto airbox and a Delkevic 4 into 1 w/ a Supertrapp Stubby can.  I have not road tested it yet  ( in the basement , finishing up the wiring )  but  i want some advice about rejetting .  i have a box of new jets from a previous 750K build . I believe the stock jets were 110's on this bike. I took one of the 118's out and compared it w/ the 110's . The 110's appear to have a conical shape on the business end of the jet while the 118 is a straight tube .  Can i use these jets on this bike or are there specific year/model jets ?

I know i have to road test it to get a final answer on jetting but my question is the compatibility of the style of jets ( opinions on jetting are welcome ) .

thanks in advance !

Logged
1978 CB750K
1976 CB750F SS
1978 CB750F
1979 Honda 400T
1979 BMW R65
1979 Kawasaki KZ400
2003 Ducati Monster 800 SIE
1988 Suzuki GSXF
Kawasaki 200 KDX
Yamaha YZ 250F
1986 Kawasaki KZ 900

Kawasaki Lakota 300 ATV

Offline Bankerdanny

  • Eventually I will be old enough in reality to be
  • Really Old Timer ...
  • *******
  • Posts: 7,623
  • Endeavor to persevere
Re: 1976 750F jet compatibility
« Reply #1 on: November 30, 2018, 12:30:35 PM »
105 is stock for your bike. I believe the OEM Keihins I bought for my F have a beveled end where it screws into the holder and flat on the bowl end. JetsRus has pictures at their website. For some reason the '76 isn't listed, but jets from the 75 K are the same style.
Logged
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline david 750f

  • Expert
  • ****
  • Posts: 827
  • 1976 CB750F
Re: 1976 750F jet compatibility
« Reply #2 on: November 30, 2018, 01:10:55 PM »
Bankerdanny is correct. 105's are stock. Make sure the jets have the K (looks like a star) for Keihin stamped on them (hard to see sometimes). You may have aftermarket jets.
« Last Edit: November 30, 2018, 01:12:48 PM by david 750F »
Logged
1976 CB 750F

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,289
Re: 1976 750F jet compatibility
« Reply #3 on: November 30, 2018, 01:20:42 PM »
The external shape of the jet is irrelevant.  The thru-put hole size is where its at.   
how many turns out from seated are your IMS? What is your pilot jet size?
Logged
'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 mine…"

Offline Handlebar

  • Enthusiast
  • **
  • Posts: 191
Re: 1976 750F jet compatibility
« Reply #4 on: November 30, 2018, 03:12:25 PM »
Use your chock lever as a tuner,try a little chock thru the rpm range, and listen closely. you will find the lean areas.
Logged

Offline Don R

  • My Sandcast is a
  • Really Old Timer ...
  • *******
  • Posts: 21,624
  • Saver of unloved motorcycles.
Re: 1976 750F jet compatibility
« Reply #5 on: November 30, 2018, 03:39:04 PM »
 Flow on jets can be tuned by the bevel of the inlet. It does matter, stay with kiehen's you'll be ok.
Logged
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline Tracksnblades1

  • My Son was a collegiate competition Trap, Skeet, and sporting Clay
  • Master
  • *****
  • Posts: 2,101
Re: 1976 750F jet compatibility
« Reply #6 on: November 30, 2018, 03:48:14 PM »
+2    105main, 40 idle,  rod 3 notch (middle) all stock for 76f
I think they had their own emulsion tube no longer available.
Their needle seats had small screens on the original ones.

36 years ago added a Yoshimura 4-1 and oval smooth bore KN pods adapted to stock carbs. Main jet 112.5, rods 3 notch, idle 40. Sometimes you had squeeze the tank with knees in a hard crosswind. I'd probably keep the original air box today.
« Last Edit: November 30, 2018, 03:51:25 PM by Tracksnblades1 »
Logged
Age Quod Agis
Pages: [1]   Go Up
« previous next »