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Discussion Starter #1
Borrowed from an antique Chiltons manual
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"

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
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"


Hope this helps you out.
 

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Need to find the specs for the 754A Carb.

I have this:
Carburetor Keihin 754A, 759A

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

I have the Honda Factory Service Manual, have some 759 info, the older ones too, but nothing on the 754A....

I always seem to have odd equipment...
 

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Discussion Starter #3
Yeah, the 754's and 759's seem to be another mystery carb for 1976 only. I know Honda has records of what was used on what and when. Know a good hacker that can get into those? :lol:
 

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Sorry if this is not the best place to post this, but does anyone know the differences between the 360's "745" and "747" carbs? They seem to have the same specs and were used during the same years (I believe), but on different variants (CB/CJ vs CL). So I'm wondering just what is different between them?
 

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I think it's pressed in vs screw in air jets?
I haven't kept track, just modified them for K&N filters
There are also variations on idle adjustment cable
754A are press in, just took a look at a pair
My 1974/75 '754's' have either 98 or 100 secondary mains, 110 sounds like CJ numbers?
 

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Ya, I've noticed most of the manuals list the main secondary jets for these 360 carbs incorrectly (as seen in the first post of this thread). I just figured that started as a typo somewhere and all of the other books copied it. But I have seen slight variations in those secondaries, as you guys point out. I'm not sure if it has to do with different models' intended applications, or if the change goes along with some other difference on those engines (such as different style exhaust systems requiring different jetting, for example).

PJ, I had my 747A carbs apart not too long ago, and seem to remember they had press-in air jets as well (by never trust my memory...I don't). I do recall that they has 100 main secondary jets, because I changed them to go along with some other changes on that engine.
 

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I don't trust the Honda manual for 360's, they have the wrong numbers in several places, plus, if you want to run K&N filters you need to do quite a lot of work as bike will run lean with stock jetting and get stupidly rich when correct jetting is used for top end
I treat all of them as 745B carbs for modification
 

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PJ,
Please detail the modifications you make to these carbs to run low-restriction filters.
I'm guessing possible alteration to the slide and with the needle height, but it will be greatly appreciated if you can be specific. Photos would also be excellent if you can.
Thanks in advance for your help.
Jeff
 

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Jeff,
The mods Crazypj did included changing the air jets. If you look under the slide diaphragm you will see a few ports. These regulate air into the emulsifiers. I believe he adjusted or replaced them. Some are screw in, some are press in. He's not "crazy" pj for nothing.


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Picked up a set of my 1977 CJ250 carbs that have been sitting in a wet garage last 9+ yrs
I'm in Britain at present, roof has a hole rusted through, floor about 1"~2" deep in water most of spring, summer, autumn and winter :(
Looks like I also have an underground stream broken through behind garage? (maybe a leaky drain?)
They are still in better condition than a lot I've modified though, linkages work, inside float bowls is just about perfect
The oil blowing out breather vent has probably protected them real well
What really surprised me though, they are exactly the same carb as the 74~75 CB360 in USA
Dr.Jeff, sorry, I can't detail mods, it's my hobby income modifying 350 and 360 carbs which allows me to keep playing with old bikes
There is a lot more to it than just air corrector mods
 

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Since I don't see the specs anywhere else in this sticky thread, I'll add them here.

For those of you with 722A carbs, here are the details from my '72 CL350K4:
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

The best place to get a kit for these carbs appears to be from Sirius Consolidated, Inc:
http://www.siriusconinc.com/pro-detail. ... ct_id=2906

Their kit has a main primary of #70 instead of #68, but is otherwise correct. Other kits don't seem to have the right mix of parts for a 722a (I can attest to this having ordered from Dime City which didn't included a new #68 or #70 so I ended up being short an O-ring and used the original jet). SCI's Keyster kit also includes things like the rubber plug for the pilot jet, the two new nozzles, etc. It's a full kit, but not the cheapest at $45 each.

Here's a good write up of disassembling and rebuilding a 722a:
http://cb350.blogspot.ca/2007/05/carb-rebuild.html

(Note I'm not the one to discover these links, but thought I'd toss them into this sticky thread).
 

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phaetn said:
Since I don't see the specs anywhere else in this sticky thread, I'll add them here.

For those of you with 722A carbs, here are the details from my '72 CL350K4:
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

The best place to get a kit for these carbs appears to be from Sirius Consolidated, Inc:
http://www.siriusconinc.com/pro-detail. ... ct_id=2906

Their kit has a main primary of #70 instead of #68, but is otherwise correct. Other kits don't seem to have the right mix of parts for a 722a (I can attest to this having ordered from Dime City which didn't included a new #68 or #70 so I ended up being short an O-ring and used the original jet). SCI's Keyster kit also includes things like the rubber plug for the pilot jet, the two new nozzles, etc. It's a full kit, but not the cheapest at $45 each.

Here's a good write up of disassembling and rebuilding a 722a:
http://cb350.blogspot.ca/2007/05/carb-rebuild.html

(Note I'm not the one to discover these links, but thought I'd toss them into this sticky thread).
This post was super helpful! I went and checked, and I've got size #70s in my carb. This is either due to the P/O buying a kit like the one you listed or he found the #70s ran better. If I were to install the #68s, and it did cause an improvement, is it going to be a fairly big one? Or would it not be worth the money?
 

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I don't know if anyone is still watching this thread... My question is about the secondary jets I just got for my carbs. One opening is a bit bigger than the other - which side is supposed to be facing the float bowl?
 

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Discussion Starter #16
Yes, all threads are pretty well monitored. I don't know much about these carbs but someone should be along that can help out. If not let me know in a few hours.
 

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Dr.Jeff said:
PJ,
Please detail the modifications you make to these carbs to run low-restriction filters.
I'm guessing possible alteration to the slide and with the needle height, but it will be greatly appreciated if you can be specific. Photos would also be excellent if you can.
Thanks in advance for your help.
Jeff
Sorry, I spent several years working it out, the modifications I do even work with stock airbox which really surprised me as they are for K&N fitting
Mail me the carbs and I 'fix' them plus check/blueprint/repair pretty cheap
I won't recommend any cheap 'pod' only K&N RU (or RC) 1820
I can't afford to give away this information, it's one of the few things I can do to make money (see avatar, that's 'titanium race parts' ;) )
Here's some info/pics though
Repaired choke plate, spring was broken

broken mounting plate, carbs could not be synced properly, crack on left plate

What parts are where, people usually confuse primary and secondary main jets plus can't find pilot/slow/idle jet (same thing, different names)


side of carb this is left carb, right is 'reversed'

Fuel air ratio of partially modified 360 carb, 115 secondary main jet, stock pilot and primary main jet.RPM at start point is wrong, should be 2,100, it's the reason I no longer make or sell replacement air jets
You can see stock 68 primary main is just about perfect with K&N fitted
It's rich enough to cause a miss-fire though at higher rpm


Majority of people know by now I make vacuum adapters specifically for CB360, plus, I make the plugs for throttle shaft if yours are missing

CB350, common fault, the jet holding spring either rusts away or breaks


Someone on eBay is now making a stainless steel replacement
Bit expensive at $16.00 each but probably worth it if you intend to keep the bike
 

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Stock jetting on CB360 is 35 pilot, 68 primary main, 100 secondary main
CL and CJ are covered on page 1
CB350 has a rubber plug instead of screw in plug over pilot jet, it needs to be in place
 

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crazypj said:
Stock jetting on CB360 is 35 pilot, 68 primary main, 100 secondary main
CL and CJ are covered on page 1
CB350 has a rubber plug instead of screw in plug over pilot jet, it needs to be in place
My 76 has 35/68/110 on 754a carbs. 759 carbs are also that size.


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