Help set floats on CB350 carbs..

Im working on a set of CB350 carbs and I am having a hell of a time setting the float height. This isn't my first rodeo, im not sure why im having such issues. Here is a pic of how I am measuring. Carb tilted just until the float notch rests on the needle, before it starts to compress. Measured from the carb body to the top of the float.



According to the manual, floats should be at 19mm. However, I cant even get the float down to 19mm.. it bottoms out on the carb at 19.21



Here is where it looks more like a normal resting place.. comes out to almost 25mm



WTF am I doing wrong? I have a second set of 350 carbs, but I run into the same exact issue with them. (wifes hands, not mine)

Which carbs are you running? I'm running 3D (stamped on the side of the body) and I swear mine were 25mm. Different carbs for the cb350 have different float heights. Let me dig up the table I used.

Setting Mark | 350A | 3-C | 3-D | A | 745B | 747B |
--------------------|------------------------------------------------------|
Venturi Bore | 28 mm | 28 mm | 28 mm | 24 mm | 28 mm | 28 mm |
--------------------|------------------------------------------------------|
Main Jet Pri. | #60 | #70 | #70 | #120 | #68 | #68 |
--------------------|------------------------------------------------------|
Main Jet Sec. | #115 | #110 | #105 | --- | #68 | #68 |
--------------------|------------------------------------------------------|
Air Jet Pri. | #50 | #150 | #150 | #150 | #150 | #150 |
--------------------|------------------------------------------------------|
Air Jet Sec. | #50 | #50 | #50 | --- | #50 | #50 |
--------------------|------------------------------------------------------|
Pilot Air Jet | #90 | #90 | #90 | --- | #85 | #85 |
--------------------|------------------------------------------------------|
Needle Jet | --- | --- | --- |2.515mm | --- | --- |
--------------------|------------------------------------------------------|
Slide Cutaway | --- | --- | --- | 2.5 | --- | --- |
--------------------|------------------------------------------------------|
Pilot Jet | #38 | #35 | #35 | #40 | #35 | #35 |
--------------------|------------------------------------------------------|
Pilot Screw Turns | 3/4±1/8 | 1±1/8 | 1±1/8 | 1±1/8 | 1±1/8 | 1±1/8 |
--------------------|------------------------------------------------------|
Float Level (mm/in) | 19/0.75 | 21/.83 |26/1.05|26/1.05**|18.5/.73|18.5/.73|
============================================================================

I have two junk carbs that say 3D (original), I have 1 good carb that says 3D, and 1 good carb that says 722A KG (Purchased from member). I dont even see that one on your list below

there are slightly different molds, but everything looks to be the same about them. Left is the 3G right is the 722A



Now, here is a comparison of the original 3D left, and good 3D right. The difference being the jet you can see on the top of the pic.

Yep, you'll want 26mm. The 3D and the 722A both share a lot of the same jet sizes. I'd probably start with a 68 primary in both and see how it runs.

Carb model 3D, 722A, 726A, 728A
engine serial # 1065279 and subsequent
Float level 26mm
Standard main jet #68 primary (722A,726A) #70 primary (3D,728A)
Scondary #70 (3D,728A), #105 (3D, 722A, 726A)
Standard slow jet #35
Idle mixture screw initial setting:
3/4 turn from closed (3D)
1 1/8 turns from closed (722A, 726A, 728A)
Idle speed 1200rpm.

Dragonfish said:

Yep, you'll want 26mm. The 3D and the 722A both share the same jet sizes, bore size and float height.

Carb model 3D, 722A, 726A, 728A
engine serial # 1065279 and subsequent
Float level 26mm
Standard main jet #68 primary (722A,726A) #70 primary (3D,728A)
Scondary #70 (3D,728A), #105 (3D, 722A, 726A)
Standard slow jet #35
Idle mixture screw initial setting:
3/4 turn from closed (3D)
1 1/8 turns from closed (722A, 726A, 728A)
Idle speed 1200rpm.

Click to expand...

Thanks honda, for making the 350 crazy as shit to find the correct information.. Should just rip the carb pages out of my service manual so no one looks at it again. Thanks Dragon

This site has lots of good cb350 info.

http://benmiranda.com/my-honda-cb350/

Wow Jordan, you're nails look great.

Thanks, I try to take care of them

Interesting topic but I cannot see the photos, can you?

JOR