adjust carb floats question (with pictures)

[MN_Scoot]

In the below service manual for a Kymco Agility 50, they show adjusting a carb float holding the carb upside down. They take a measurement with the float valve facing you with your measurement device "parallel with the main jet."


However, when I do that, I'm not even close (the service manual's 17mm is marked with marker on the ruler):


After talking to other people and reading tons of forum posts, I see that a lot of people flip the carb over and hold at an angle where the metal tang just makes contact with the float valve pin. However, when I do that, the tang already "just makes contact" when the float is extended its very furthest (part of the float has a built in tab to prevent it from going further). Still though, while being extended the furthest possible, it still falls short of the 17mm the Kymco service manual says it needs to be adjusted to. As you can see, I'm taking my measurement parallel to the main jet.


I tried measuring from the end of the float as well, but still doesn't seem to add up.


I talked to a mechanic at my local shop who said it could be a typo in the manual. If so, the 17mm is repeated more than once. He also noticed that the bolt pattern on the bowl in some of the pics didn't exactly match mine, so maybe those measurements are erroneously for a different carb.  Any ideas on if I am doing something wrong? I've also read in different places that plastic floats aren't adjustable. Would appreciate any advice to help me feel confident I got the measurement correct before I put the bike all back together. Would prefer to get it right now since there is a foot of snow on the ground vs. tearing into again when the weather's nice!

Thanks!

[wordslinger]

MN_Scoot, that looks very normal to me..the positioning of the float in your pics...the key is that it holds the valve open when buoyancy of the fuel holds it up, very much at all...

..I just measured an old, yet functional a50 carb float... @ 8mm...

..and I have never seen a faulty float in any scoot's carb...ever..

[ophelia]

Perhaps there may have been a different carburetor specified sometime during the Agility's production run. Luckily wordslinger has a spare carb to check for the relevant measurement.

I agree a faulty float probably isn't very common, but for what it's worth I fixed up an old high mileage Yamaha BWs 50 a month or two ago. The owners complained about awful fuel consumption, but it turned out gas was discreetly coming out the overflow tube and trickling down the back side of the swing arm. Either the float, the float arm, the float needle or the seat was out of spec, since the float height was way out of range.

[wordslinger]

..yeah, could overflow...

..how old is this carb, anyway?

..been smelling fuel?

[MN_Scoot]

It's the stock carb on an '07 Agility.

I didn't really smell gas, but since it has been getting really low power off the line (I had to give quick throttle twists at stop signs to keep it from killing until it got past 5-10mph), I thought I'd try to clean and readjust as much as I can to hopefully solve.

I just had the body panels painted and want to get everything in the best mechanical order before putting back together.

[wordslinger]

..any mods ?

..other than new paint??

..I stared and compared oem carbs, and I think the float is fine....not sure whats going on in the service manual...Mines says the same thing...

[CROSSBOLT]

MN-scoot, look at the manual picture you posted: the kymco picture shows about 12 mm! Regard the 17 mm as a typo. Regard the "angle technique" as purposely misleading. Hold carb upside down & level. This compresses the tiny spring in the float needle LIKE IT WOULD BE TO SHUT OFF THE GAS! The float "height" will be when the float is level or parallel to the carb flange. Or the seam in the float is parallel to the flange.

Karl

[wordslinger]

..very good explanation, Karl!


               

[MN_Scoot]

Yeah, I noticed their picture being around 12mm, too. Again, the guy at the moto store I go to noticed the bolt pattern on the float bowl being slightly different as well.

The second photo in my image was actually the level upside carb. Though the seam in the float is just slightly below the carb flange, it is equally below on front and back -therefor the seam and the flange are level. To further confuse things, the measurement in that second image is just 8mm.

Given the feedback here, I'm kind of operating under the assumption that both that photo and 17mm they list are errors in their service manual and that my float level appears to be fine. Let me know if anyone thinks otherwise, though. Some of the pages even say "Philly" then jump back to "agility." I don't get the impression a lot of care was take on that service manual.

Thanks again for all the feedback!

[MN_Scoot]

Couple follow-up ?'s:

A couple of the rubbers gaskets are looking a little rough. Is this the best place to get those types of parts?
http://www.kymcopartsmonster.com/p/Kymco-Scooter-Parts#/Kymco_USA/KG10SA_AGILITY_50/E05_-_Carburetor/04%7c%7e40%7c%7e0005/04%7c%7e40%7c%7e0011
-I'd like to find some of the little O-rings at a hardware store, but I read they have to be gas resistant which is harder to find.

If worst comes to worst, would this slightly different carb be easy to pop in and adjust? They talk about it being 19mm and an improvement over the stock 17mm.
http://www.monsterscooterparts.com/kymco-agility-50-19-mm-carburetor-with-electric-choke.html

[wordslinger]

..a 19mm carb alone, will only cause headaches trying to get the fuel mix right...

..Unless you're upgrading with a free-flow filter, and possibly a pipe, then don't bother with a 19mm carb...

..that might be a good sight, I don't know, as I buy all my oem kymco parts at
"www.stadiumyamaha.com" ...

[wordslinger]

..there's a cpl links below that I posted waaay back in the day...

                         


..float looks th same...



http://www.kymcoforum.com/index.php?topic=1923.msg12992#msg12992


http://www.kymcoforum.com/index.php?topic=1924.msg12993#msg12993


http://www.kymcoforum.com/index.php?topic=1925.msg12994#msg12994

[CROSSBOLT]

Tank you, Word! Tank you, tank you! Or tanx if it works better! O-rings at auto parts stores are pretty reliable for fuel since that is the customer base preference. Lotsa sources for o-rings including the airplane suppliers. The books are really a joke but it will improve with time just like Honda in the '60s: they were terrible with the Japanese to English syntax and translations. But they got way better.....with time.

Karl

[wordslinger]

..woop-woop!!


..dang, glad I could help!!


               

..generally, Viton O-rings are available in any size.. just google a location in your zip code...

..they hold up well in contact with fuel...