Carbs - Setting Float Bowl Height (some questions)

[Chuckster]

I found a carb rebuild thread in which Steve posted a very good response and picture (see below) regarding setting float bowl height.

I need to know the following if anyone can help:

1) What do I use to measure the height and where do I get one?

2) If I need to make an adjustment, what do I "bend" :shock: (for lack of a better term)?

3) What do the numbers below mean for mine regarding float height and what type of measurement is this?

The specs for my bike are:

GS550 (80-82) the specs are for the CV's

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 47160 (us) 47170 (can)
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-0.5 (0.20 +/-0.04)
main jet #92.5
main air jet 1.6
jet needle (4bel2 us model) (5f42-3rd notch canadian adjusable needle)
needle jet x-6
pilot jet #40
throttle valve #135
by pass (0.9, 0.7, 0.7 us model) (1.0,0.8,0.8 canadian)
pilot outlet 0.7
valve seat 2.0
starter jet #35
pilot screw 3.5 turns back (mixture screw)
pilot air jet (us model #150) (#120 canadian)

 

[Nessism]

Search for BassCliff and go to his website. The info is there.

 

[Guest]

1. best use caliper/vernier, you can likely buy it at any tool store. you can use a small ruller too, if you're good with taking measures
2. yes, you do BEND, it's the float bracket, you'll figure it once you have an open carb in front of you
3. not sure what you're asking here

 

[BassCliff]

A little more info

A little more info

Mr. Chuckster,

As Mr. Nessism has pointed out, I am collecting pertinent GS information on my little BassCliff website. There are some pictures of the measurement process here. Thanks again to Mr. Steve for the pictures. The measurment device of choice, like Mr. psyguy says, is a digital caliper. Note that the measurements are metric (millimeters or 'mm') along with the equivalent American inches. The inches measurements are the ones in (parentheses).

Float height is 22.4mm plus or minus 1mm OR 0.88 inches plus or minus 0.04 inches.

<<Use this end to measure float height.


Thank you for your indulgence,

BassCliff

 

[Steve]

Just to give you a better idea how it's measured:

and then a close-up of the end:

Next question? :-s

You know that if I don't have a picture to answer it, I'll just get the camera out and take one. 8-[


.

 

[Chuckster]

Thanks y'all. You guys are great. Pictures speak volumes. The digital caliper looks expensive! :shock: Can you give me any idea how much they are and the best place to get one? Also, if it is rather expensive, is there a lesser expensive caliper I can use to get it done? -Chuck

 

[Steve]

Thanks y'all. You guys are great.

Of course we are. :-\"

Pictures speak volumes.

Yes, they do.

The digital caliper looks expensive!

Is $16 too much for you? 6" caliper from Harbor Freight. The picture that BassCliff posted appears to have been lifted from the HF catalog.

... is there a lesser expensive caliper I can use to get it done?

They also have a model for $6, but it does not have the little tang that comes out the end that makes it so handy for measuring float height. Resoultion on that model is only .01", so its value is limited for our purposes. Probably a fine unit for many other things, just not the right tool for what we want.

BONUS TIME...these same calipers are invaluable at valve adjust time for double-checking the thickness of your shims.

.

 

[Chuckster]

Steve, thanks for the info on Harbor Freight. I have one somewhat near me. I figured it was a lot more than $16! I can do that. :-D

 

[chuckycheese]

Every time I've rebuilt my carbs, I've always just cut out a piece of thin cardboard and marked the correct height on it and then used it to see if any adjustment was necessary.

I've never needed to adjust them and I've always wondered why you'd ever need to, once they're correct. The only way it would ever change would be if your needle valve was 'out of whack', in which case, you'd replace that.8-[

 

[bwringer]

Every time I've rebuilt my carbs, I've always just cut out a piece of thin cardboard and marked the correct height on it and then used it to see if any adjustment was necessary.

I've never needed to adjust them and I've always wondered why you'd ever need to, once they're correct. The only way it would ever change would be if your needle valve was 'out of whack', in which case, you'd replace that.8-[

Correct -- once you get the float heights right, they should stay that way.

However, it's depressingly common to find float heights set haphazardly or incorrectly, even on carbs that have supposedly been rebuilt by a pro, so you do have to check them with your own eyes and set them with your own hands at least once.

You will also need to re-check and re-set float heights if you replace the needles and/or seats or if you replace the floats.

 

[robertbarr]

I figured it was a lot more than $16! I can do that. :-D

They sure used to be! Look up 'Mitutoyo' or 'Starrett digital' on ebay, but the price of these has dropped a lot in the past six years or so too. No more vernier scales.

These things became extremely affordable just about the time I started using trifocals. Talk about timing!

They are highly useful.

 

[bwringer]

I posted this in the other carb thread going on right now, but it might also be useful here.

 

[Texas]

bent floats

bent floats

The PO bent the float arms (where the X is on the pic) instead of bending the tab. I straighted. As close as possible. As long as I adjust hight as prev described will I be ok? Floats good other than that .

 

[Suzuki_Don]

The PO bent the float arms (where the X is on the pic) instead of bending the tab. I straighted. As close as possible. As long as I adjust hight as prev described will I be ok? Floats good other than that .

It would be best for you to check the actual float level with the plastic tube from drain plug procedure as explained in the Suzuki manual for that particular carb.

 

[Steve]

The PO bent the float arms (where the X is on the pic) instead of bending the tab. I straighted. As close as possible. As long as I adjust hight as prev described will I be ok? Floats good other than that .

Since you know that the floats have been tweaked, be sure to measure both floats, make sure that they are very close to the same reading.

.

 

[Texas]

float arms

float arms

Thanks guys, just glad I don't have to trash them.

 

[donimo]

It would be best for you to check the actual float level with the plastic tube from drain plug procedure as explained in the Suzuki manual for that particular carb.

anyone know what this means to help out a guy without a manual?

 

[Nessism]

anyone know what this means to help out a guy without a manual?

How can anyone own a 27 year old motorcycle and not have a manual?

You need to make a tool that has a threaded rod that screws in place of the floatbowl drain screw and a piece of clear tubing. Shouldn't be too hard to fabricate by drilling a screw.

 

[waterman]

Do you check fuel height with engine idling or can it be measured statically with carbs held in a vice? I have measured mine statically since I figured it would be a pain to install carbs, measure, adjust, reinstall, measure again, etc.

Nice post with pics, should be made sticky.

 

[Larry D]

anyone know what this means to help out a guy without a manual?

Read this...the search feature works wonders !!


http://www.thegsresources.com/_forum/showthread.php?t=116329&highlight=bowls