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Carb Information CB/CL/SL 350's and CB/CJ/CL 360's

LongDistanceRider

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Location
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Borrowed from an antique Chiltons manual and other sources
The information I have on the CL/CB 350 is:
Engine number 1000001 thru 1045164
Carb # 350-A

Venturi 28mm
Main Jet Primary #60, Secondary #115
Air Jet Primary #50 , Secondary #50
Pilot Air Jet #90
Pilot Jet #38
Pilot Screw 3/4 +/- 1/8 turns out
Float level 19mm or .75"

Engine number 1045165 thru 1065278
Carb # 3-C

Venturi 28mm
Main Jet Primary #70 , Secondary #110
Air Jet Primary #150 , Secondary #50
Pilot Air Jet #90
Pilot Jet #35
Pilot Screw 1 +/- 1/8 turns out
Float level 21mm or .83"

Engine number 1065279 and later
Carb # 3-D

Venturi 28mm
Main Jet Primary #70 , Secondary #105
Air Jet Primary #150 , Secondary #50
Pilot Air Jet #90
Pilot Jet #35
Pilot Screw 1 +/- 1/8 turns out
Float Level 26mm or 1.05"

Keihin 722A carbs used on the K4, K5 and G models
Main Jet Primary #68 , Secondary #105
2.2 Float needs and seat
Pilot Jet #35
Pilot Screw 1 & 1/8ths +/- 3/8 turns
Float Level 26mm

SL 350
Carb # A
Venturi Bore 24mm
Main Jet Primary #120
Air Jet Primary #150
Needle Jet 2.515mm
Slide Cutaway 2.5
Pilot Jet #40
Pilot Screw(turns out) 1 +/-1/8
Float Level 26mm or 1.05" except SL350 K1-K2 which is 25mm or .98"

CB/CJ 360 ​See post #5 for updated information
Carb # 745B
Venturi Bore 28mm
Main Jet Primary #68 Secondary #68
Air Jet Primary #150 Secondary #50
Pilot Air Jet #85
Pilot Jet #35
Pilot Screw (turns out) 1
Float Level 18.5mm or .73"

CL360
Carb # 747B
Venturi Bore 28mm
Main Jet Primary #68 Secondary #68
Air Jet Primary #150 Secondary #50
Pilot Air Jet #85
Pilot Jet #35
Pilot Screw (turns out) 1
Float Level 18.5mm or .73"

Keihin 754A, 759A
Jet Main Secondary : #110 99114-246-1100
Jet Main Primary : #68 99101-369-0680
Jet, Slow : #35 99124-286-0351



carbspecs-jpg.53298
 
Last edited:
Hey LongDistanceRider,

Looking at this chart it seems like there are a lot of CB350s that fall into the "later" section. Do those same settings apply for all of them? For instance my bike's engine number starts with a 3, should I be using the "later" settings?

Just wanted to double check since I've seen a lot of varying information out there on the web.
 
A 3 engine means you've got a K3 which should have the 3D carbs and yes they were all jetted the same regardless of year or model. So much easier than the SOHC VB carbs which changed every year and by model. 1973 K5 models used 722 carbs which are different for parts and jetting so check the stamped carb number.
 
The chart was copied from Honda manual and is WRONG.
Even Honda re-printed it multiple times, printers don't know or care what they are printing as long as it isn't smudged and can be sold to customer.
I think there was a Service Bulletin but I can't find it (can't find the set I got in 2006)
CB 360 specs are
Air jet, primary 150
Air jet secondary 50
Air jet slow (pilot) 80
Slow jet 35
Primary main jet 68
Secondary main jet #Varies by model but anywhere between 95 and 110, most are 100
Float height 19mm (use 21mm with E10 fuel)
I found out something I find interesting, the pilot jets are a very weird size.
I've worked on 250/360 carbs for over 40 years but never needed to know this before.
I'm modifying and repairing an incredibly nasty set and had to fit an insert for pilot jet.
It's a TAPER thread (like a pipe thread) BUT, #6x40 at small end and ? at large end. (UNF thread is the closest I've been able to find)
Aftermarket jets seem to be #6x40 and not tapered.
So, it may be some Kei-Hin special as I haven't been able to find out anything on a #6x40 taper thread
 
Dug out my Pitman Bike Book by John Thorpe 1976.,
Gives some weird and wonderful in formation!
250, venturi diameter, 13.4mmx27.4mm
Primary main jet, 55
Secondary main jet, 110
Pilot (slow) jet 35
Primary air jet, 50
Secondary air jet, 60
pilot air jet, 90
Bypass jets (these are drilled directly into carb body, PJ) 0.7mm, 0.8mm
Needle jet, 2.6mm
Needle, 2.395mm, 3 degrees, 30 minutes
Idle fuel screw, 1-1/8 turns out +/- 1/8 turn
Float height, 21mm +/- 0.5mm from flange
I suspect the information was pulled directly from Honda service manual so may have the same misprints and mistranslations?
The 350 spec gives larger venturi diameter, 14.5x28mm, primary main 60
secondary main 115
pilot 38
jet needle 2.595mm, 3 deg 30 min
float height 19mm (I think that is for the early 'square' brass float which is pretty rare, I've only ever seen one set with them)
 
Thanks crazypj !!!! .. I had that book in the late 70's by John Thorpe !

I have a couple of sets of those 2C carbs with the 'squared' floats
 
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