I have been working under the assumption that the float height on our carbs is set from the raised lip around the gasket surface of the float boat mounting flange. On the PW26 carbs, there is a notch in that flange on each side of the carb.
I have been using the top of the lip at my zero point for my scale. The manual is not 100% clear because it does not show the notch and is for the PW22 carb.
So, I did a search here and found the following.
1. A sticky that shows how to make a tool that measures the spec dimension from the base of the notch.
2. A post that says the dimension should be measured from the gasket surface with the gasket removed.
3. A reply to the post in #2 above that says the dimension should be measured from the top of the lip.
4. A post that references Loud Mouse's method which says set the floats to the top of the jet holder. I could not find LM's actual post that recommends this.
So, IMHO, I don't think such a basic point should have so many different recommendation on this site. Would someone who truly knows the CORRECT answer, tell me from which surface the 22.5mm float height should be measured for a PW26 carburetor.
Thanks,
Rob
How do you set the float height to specs?Interesting. I've always (well, for about five decades) believed #2 was correct, and followed that procedure. After your post, I resorted to looking at my genuine 1963 Honda Maintenance Manual, and it shows #3 as the proper method. So, now I get really desperate and find a set of the float level gauges that Honda offered (had them since the late 60's, but never used them), and they measure 22.5mm as based on version #1. The specified height in the manual is listed for the Pw26 is listed as 22.5mm, and 26.5mm for the Pw22, so that's consistent. Guess we'll see a bit of controversy on this one. Regards, Chase
Chase, you have given me the idea to check other Honda Manuals I have. I also have an old Clymer's that covers several model years. My goal was to see if there was a standard convention across various models.
For two other models, the diagram that shows how to measure it shows the notch in the rim/lip of the bowl mounting flange and the dimension is measure from the bottom of that notch. So that agree with #1. The models are the S90 and CB/CA 160. In both cases the top of the rim is shown as a dotted line. Other models in the Clymers show no lip or notch. My CL72 manual, which is much better than my CL/CB77 manual, shows no notch. It also shows the float below the level of the top of the jet holder. But diagrams like this are not intended to be portray a true view. So, the gauge and standard convention shown for those other two models lead me to believe it is measured from the notch. By any chance does the PW22 used on the CL72 NOT have a notch? That might explain why the diagram conflicts with the tool on the PW26. regards, Rob The factory manual I have does not show a notch, just the outer lip. I was shown the #2 carb gasket surface method by a mechanic at the local Honda dealership in the early 60's, but that certainly doesn't mean it's correct. The #1 bottom of the notch version makes sense as it is a machined reference surface (not required for gasket sealing, and no other obvious reason for it to be there), and the gauge uses the bottom of the notch to locate on. With the Pw26 carbs, lm's line of sight method to the jet holder may well agree, I'll check later. Unfortunately, I don't have any other size carbs to compare to see if that holds true in all cases. Regards, Chase
Made a gauge to set the floats to 22.5mm using the notch. Just came in from setting both floats.
When I got done, both floats hit the back of the float bowl before running out of spring travel in the float needle. I don't like that. It also puts them about 1.5 mm below the top of the jet holder. I think that tomorrow I will raise the gauge to about 24mm from the notch. I think that will put the floats close to 22.5mm from the top of the lip. And obviously closer to the top of the jet holder. I'm leaning towards using the top of the lip. You said your gauge measured 22.5mm. Did you actually measure it, or is it stamped on the gauge? I ask because if the top of the lip is correct, then the gauge could be slightly longer to accommodate the notch, but be stamped with the spec dimension. I'm probably splitting hairs here and a few mm's too high is nothing unless you are running wide open all the time. I'm waiting for LM to weigh in here since I have a lot of respect for his experience. I knew a guy who was a top Honda mechanic when before he came to work for my old company. I'm going to try and find him and see if he remembers. regards, Rob
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