CB/CL 200 float height setting

[Jramos13]

Hi all. I've been trying to search for a clear answer regarding the float height setting for a 200. Some say it's from the lip, some from the gasket surface. There's an old pictures from a chillón manuals somewhere saying it's from the gasket surface. In the cb/cl200 manual just says to measure 21mm and the pictures appears that it's being taken from the lip.



In my experiences, when measuring 21mm from the gasket surface the plugs were fouling with gas. However, I was not running OE needle valves seats. So I put the needle clip one notch above center and measured 21mm from lip. Things did improve, got a more brownish color, but still rich at some point in the throttle range.




Today I re-rebuild the carbs with all OE parts, including floats and needle valves. I was thinking of using some clear tubing connected to the bowl drain bolt and see where the actual level is at 19 and 21mm.
Should the fuel reach the flat surface, the lip or be higher than that?

 

[stl360+450]

My interpretation of the instructions "distance between the carburetor body and the opposite edge of the float" would be the shortest distance, i.e., from the lip rather than the gasket surface. The picture seems to be doing this also.

Did you adjust the idle mixture using the mixture screw prior to noticing the gas fouled plugs?

As far as where the actual fuel level should be, that isn't really made clear by the instructions since those refer to the float and not the fuel. I would expect it to be somewhere between the bottom of the float and the top of the float and I guess you could get some idea by seeing how the float sits on gas outside the carburetor (in the correct orientation).

 

[Jramos13]

Yea. That's what I think to, from the lip, which is part of the carb body. After adjusting the air screw things got better. It's currently 1 turn out. The CL200 calls for 5/8, but it was still to rich at 5/8.

I saw some models do have a grove where you can put the gauge tool in the flat surface, however in the cb/cl200 model there's a grove in just one side. The thing with the level is that the position of the actual float could vary depending on the bend of the tang

 

[stl360+450]

After adjusting the air screw things got better. It's currently 1 turn out.

Good. Obviously, the idle mixture is affected by multiple variables, with the mixture screw being the easiest to change.

The thing with the level is that the position of the actual float could vary depending on the bend of the tang

Exactly. I do think the fuel level relative to the float height is more or less fixed, though, but it would require some float tests in gas to determine how high it sits on the fuel.

 

[ballbearian]

I'm rebuilding a set using all aftermarket brass, floats, valves, etc. There are just too many variables to assume float height can get you perfect. I think the clear tube method is the only way to conclusively verify the actual fuel level and that's what really matters.

 

[Jramos13]

Today I was able to test it out, this is at 21mm from the lip. I think if I got to 19mm (21 from the surface) I think it might be overflowing.

 

[Amannl]

I know this issue has been discussed to death in multiple forums but, at least according to the CB160 manual, the float height should be measured not from the lower lip but from the base of the gasket surface.

i have a Keihin float tool for my CB450 that fits in the grooves of the carb. I believe that whether a carb has the cutouts the float level should be measured from the gasket surface not the lip. But that’s just one man’s opinion.

 

[Jramos13]

The cl200 only has a cutout in one side, so it is not possible to measure it from the gasket surface directly, usually 3mm are subtracted from the 21mm

 

[ballbearian]

Great. Now I hope to hear comments from our more experienced members. If the bowl is not level then perhaps the centerline (the wire clip) should be the reference point.

 

[Jramos13]

Great. Now I hope to hear comments from our more experienced members. If the bowl is not level then perhaps the centerline (the wire clip) should be the reference point.

This was with the center stand. Looking fwd to others with more experience to chime in too! I'm going to run it during next week like this to see how it goes.

 

[Dmoh]

Having played around with carb settings for many years on my 1973 CB200, I've come to the conclusion that Honda's engine adjustment specifications were designed for a brand new bike.

Now that mine is over 50 years old, and probably still on its original pistons (I've never had the motor out!), I've set up things to cope with sub-optimal, but even, compression (145psi each side), and possibly other unknown wear factors.

As a result, I'm now running D7EA spark plugs with a lean float setting and the bike runs great for my current mild use. It'll comfortably cruise at 50mph (80kph), which is the speed limit on most roads I frequent.

Of course, were I to pin the throttle, I'm sure the bike would not last long in its current state. If I want to ride that way, I'd need to do a top-end rebuild, and I'm too lazy to contemplate that at the moment!

In summary then, if you know the health of your engine (compression test), you can compensate for that with adjustments that will make the bike rideable for you.

Good luck with your maintenance.

Dennis

 

[NeverEverJamToday]

It's 21mm, from the gasket seat (gasket removed) just as the tang meets the properly seated needle/valve, to the other float side.




recommend submerging floats in gas before installation, to make sure no pinholes are present.lightly shake them to listen for intruded fuel. I've had to replace all the original floats due to this issue.

 

[Jramos13]

I used new oe bowls. The thing with 21mm from gasket surface is that I was having a rich condition the first time I tried it a while backs when I went 21mm from the lip, the bike started to run betters that's why I used the clear tube in this case. Plus the manual is very vaguer regarding the point of measuring.