How-To: Adjust FLOAT Height & Clear Tube Method

[@anthonyfriedrichs8782]

G'day Matt, after struggling for about 3 months trying to set the float level on my 1992 Suzuki GN250 I used your clear tube method and my bike is running great. This was after installing a new carb kit . Thanks a ton for the excellent explanation. Ant.

[@djlancer88]

3 months? Im ready to give up after a day lol. Thanks to this comment I shall not give up. Doesnt help my ebay kit has wrong size pieces and the bike is 38 years old

[@Marco-qe5zw]

that seems to be the best method in my opinion.

[@joshduff8989]

Thank you! The clear tube method is the way to go. This helped me confirm a too-high fuel level and fix a rich running condition in the low range. 👍👍

[@choppergirl]

I put a brand new plastic non-adjustable float in my Honda Rebel. It idles fine with choke all the way on, but as soon as I twist the throttle it stumbles, and my float bowl is leaking. If I get well past the stumbling, it will run just fine. I'm guessing my fuel bowl height is wrong, but I have no idea what to do at this point. I rebuilt the whole thing with a new kit and cleaned it and everything and made sure it was all put together properly according to videos. And now I find out about.. THIS. I didn't even know it was a think, I thought the float bowl operation was an ldl0t proof system. Just a float on a hinge with a needle. Brilliant, I'm going to try this.

[@henrysmith8012]

Been doing the clear tube method for 20 years. Simple.

[@donovanlucibello379]

My kids and I have been following you for years, Matt. (Another) solid video!

[@HTMR]

Awesome thanks!

[@stevenrandall9601]

Thanks for the great instructional video! Very helpful. I found out my floats needed a twist to be balanced.

[@domarabadal9991]

Thank you, excellent explanation and great work. Keep it up my friend. From Toronto, Canada

[@battler544]

Great video, just to add to your advise, the T pieces on the carburettor fuel rail should be carefully inspected for leaks prior to installation.

[@TrailBoundco]

aren’t you supposed to take the measurement with the carb at an angle not completely upside down?

[@01thomasss]

Hi. The non-adjustable plastic floats can be adjusted a bit by shimming the float valve seat.

[@adamsyfqqq]

thank you for the useful tips Talita!!

[@oomrah9748]

How?

[@01thomasss]

@@oomrah9748 Unscrew the seat from the carb body and place a shim under it then screw it back again.

[@edwarddorado1763]

First of all most excelent instructor i looked at a lot of vedioes (sorry bout spelling fat fingers) got a guick guestion i got a go kart with a predetor motor i put a munki carb it acts like its runs out of gas but it dont every carb i put on same thing what can i adjust to fix i flushed tank cleaned every thing 2 or 3 times but im missing some thing im about to try the float thanks keep up the good work

[@bc-mr1si]

great video. my carb has a bowl drain outlet.fuel flows out when drain screw is slackened. can i connect a clear peace of tube to it 🤔

[@lexbrusb.1821]

INCORRECT!!! you have to measure the float height while holding the carb at a certain angle where the the plunger is barely touching (resting on) the tang on the float.

[@nokia26300]

thanks for the tip. my carb pukes gas when i twist the throttle a lil bit fast. now its fixed! i found out that i have gas up to the brim of the float bowl

[@RicardoTeixeiraCarromeu]

Good day Matthew for the pwk 24mm what is the correct float settings when I remove the bottom cover the float goes to way down that the valve even come out from the orifice. Thank you

[@daveco1270]

Thanks for the video. I've been struggling a little with my CB750 float height measuring but I think I finally got it right. I'm a perfectionist and want it be exact using my digital caliper. Most of the floats weren't even, one side would measure perfectly and the other side would be off by a millimeter or 2. I was able to bend them a bit to get them even. I can't get my clear tube to stick in the bowl drain hole like you did. It kept leaking. I ended up taking an old float bowl drain screw, drilling a hole in it and sticking a small piece of brass tube in the hole....then I glued the rubber tube to that....so it's basically a float bowl drain screw with a hole in it and a tube glued to the screw end. I'm going to measure gas level on my bench which is inside the house. Do I have to use gas or can I use water (or even alcohol) in the bowl for measuring purposes? I'm a little worried about my basement smelling like gas for the next year.

[@HTMR]

You can use alcohol, just dry it out aftrer test. Here is the fuel tank I use: amzn.to/3cdgUov

[@bc-mr1si]

with the height correctly adjusted. when you turn the carb to its upright position. how much should the needle be out its housing, half way,two thirds etc .

[@stevechristiansen9037]

Thanks for the video this will save me some time

[@rjantorno]

Hello ! all good ? My name is Raimundo, I'm from Brazil, I have a R6 2000 and I had already dismantled the carburetors before. The first time I took it apart, cleaned it and put it back together again. All very well. The second time my wife mixed up the pieces to get the plastic divider for herself. The bike is tuned, I guess it still is, as I didn't change the air intake adjustment. Now I know it has a pilot screw 152 and 148 (inside and outside) but I must have installed it wrong. can you help me ?

[@SheDevilsGarage]

Thank u sir appreciate the video my float valve has little play in it while hooked up to the floats and it leaks fuel threw drain hole a little bit when im trail riding but not on the flat ground shes a 1969 honda ct70 carburetor

[@napadaanlng69]

Some tutorials recommend adjusting the float height by holding the carb in 45 degree position? Or should i just lay out the carb in a flat surface to adjuat the height?

[@HTMR]

I forgot to mention that in the video. Reason for that is to not let the little "tit" get depressed. So, don't let it get depressed during the reading.

[@Aciecarter238]

Hey how come you dont hook the hose to the drain on bottom instead of where the drain screw is. My ninja 250 has a drain an it isnt the over flow drain. Can i uae that or do i need to use the drain screw

[@dex1257]

I broke my float when i was cleaning the jets.And now the carburator is working only on one float.Is that good because the carb isnt overflowing and is working fine

[@charleshooper9123]

What kind of ruler it's at that I need to use to measure my float levels

[@hrenken779]

Thanks Mathew! Just the information I needed.

[@mandarkumthekar8565]

If all plastic float you can rap tang by plastic piece to touch the plunger

[@pocket83squared]

This was helpful. Thanks.

[@joshsutcliffe6099]

Should I go a bit lower than factory when adding a 2.5 psi fuel pump to my bike?

[@Сава1389]

Hi! How to check float height with tube if carb is not set horizontaly on the bike,but with some angle?

[@oomrah9748]

Good question.Noone would respond because they also don't know.Your question exactly the problem I'm sitting with

[@MrJoller10]

thanks for very good showing how to make adjustment for the float :)

[@sthildas4857]

Thanks Matthew very simple plus informative. 🇬🇧🏍️

[@anonimous2451]

Gotta love those high quality Amazon Fuel bottles with leaky valves......I replaced mine.

[@JM-sb4nb]

I wish the manual would say what the fuel level should be instead of the float height. 1-2mm seems too vague. Thank you for your video. It was the best to describe the fuel level.

[@willcountypowersports6338]

Great video I also got a good laugh out of this one I hate when things go wrong when you’re filming

[@cb400fhonda6]

Just like a pro Awesome video

[@jaime7890]

Hey matthew!. Awesome video. I have a quick question. For a FCR 39 MX carb, the fuel level would also be in the same spot? (1-2 mm below bowl gasket) ?

[@burt1758]

Some carburetor measurements are with the gasket on the carb.

[@RobertMcInally]

brilliant video thanks

[@FRANZOLLI144]

Vídeo maravilhoso

[@Tamas-Ulrich]

Imma try this out with my carburetor. Before adjusting air screw. My engine won't rev up under load, unless going down from hill. It's under 8000 rpm.

[@dmo848]

Pilot screw in the carb is plugged im guessing

[@deliverance3767]

I was going to attempt adjusting my float level height but its plastic.Thanks man.I will rather replace.i have learned a few things on your channel Michael Douglous

[@HTMR]

LOL Michael Douglas

[@TN_HondaDad]

Good video, but after all of that, whey didn't you measure with a straight edge from the fuel line to the indented gasket base, per the manual it was 1-2 MM with your measuring device instead of eyeing it?

[@lk6912]

Because this isn't an exact science, it just has to be within a desired range to work properly.

[@markmckell8817]

Another great video Matthew.

[@mrfenderguy1]

That's a good trick.. Thanks for the tip!

[@napadaanlng69]

What if the carburetor is fixed in the manifold diagonally?

[@MattulaTaylor]

Good job... I get the idea. Cheers!

[@stephenfurr8769]

My Yamaha book has me adjusting my Mikuni Carb Float at a tilt, as opposed to upright like you did. I did your way the first time, then my uncle said no. Book also said no. So, I’m confused.

[@HTMR]

Yes, then tilt it so plunger does not get depressed.

[@jackpoell1673]

Thanks, great tip.

[@Andrew_From_NB]

Thanks for doing a video on this topic, I have a similar issue with my Kawasaki brute force 650i that I’m looking to review float heights on as well, cheers!

[@goneridingparts]

great video !

[@dougjones4987]

Great video

[@christsideurbanstreetminis2183]

What do you do for a carb that is at an angle like what is on the 1985 vt700c

[@chrisfischl8702]

What would be the float height on a 750 ace 2000 model

[@michaelcalderon4401]

I need to adjust mine it keeps leaking. So how does it go. If the floats are too high what happens and if they are too low what happens?

[@HTMR]

Too high of float will have a low fuel level in bowl. "Should" run leaner in that scenario.

[@michaelcalderon4401]

@HTMR I went through and rebuilt my Carburator, including the mid body gaskets. My Carburator was leaking from the float bowl vent tube where the drain screw is. Put it all back together and its still leaks from there. I have a Kehin FCR Carburator

[@DonziGT230]

1:25 "Always to the gasket mating surface." Not true. One of my bikes calls for measuring from the end of the main jet tube instead of from the gasket surface.

[@paulaskill3660]

Cracking informative video as usual Matt. Cheers

[@nynafoster1475]

what wrong with my bike the needle isnt shutting off the fuel and what i think is wrong the seat is dirty or i need a new one

[@daleerickson520]

Would this be correct for Two stroke carbs as well? I have a 1979 PE250N and I am having problems with the manuals version of the float adjustment, just pukes gas. And yes BTW the needle and seat check out but the floats may be sub par, new ones on order. BUT I was able to set as per this video... Just concerned the fuel level being 0.5 -1.0mm below the gasket surface may be wrong for this bike...

[@HTMR]

Test the float needle first: kzbin.info/www/bejne/Z3qciq1-gLtlrMU

[@nomdeguerre13]

how does this apply when carb float checks are at an angle? Really good video by the way!

[@HTMR]

Same. That is done to prevent depression of the "tit", which I totally forgot to mention in the video.

[@nomdeguerre13]

@@HTMR Thanks, appreciate the reply!

[@bradrussell624]

Hahaha...that was the funniest float level adjustment ever...LOL, thanks for sharing, freakin needed a good laugh

[@roger_roger_that]

Question: what size tube did y’all use for this?

[@henrysmith8012]

Does not matter.

[@MrGerloc]

Is it possible to use water for the clear tube method ? then clean the carb afterwards ? i dont want to spill fuel all over the place. or will it be incorrect since water and fuel don't have the same properties ?

[@lk6912]

I'd say any free flowing liquid would work especially since your going to clean it anyways lol. And I feel ya I reek like gas every time I go to mess with a carb 🤣

[@sheetalpawan9948]

Bro, good information thanks

[@allanhmelnitski978]

Im fing confused with my carb! when float height is in specs (22mm) then fuel level is bloody low, like 12mm from the gap surface - not 3-5mm.

[@anythinggarage]

Just got a new carb for the gokart and it keeps leaking fuel from the air filter side. Float to high. Never stops leaking till out gas. Ima need to try this but have no info o. These chinese carbs

[@user.256z]

yeah these chinese carbs most of the time need to be adjusted from factory, i purchased one and a vent tube was blocked off causing a leak from the air filter side, the leak was not constant but rather filled with air bubbles, check valve seat/needle and gasket from bowel make sure screws are snug

[@TMCmakes]

thanks for that first call out on plastic floats. i just encountered my first fully plastic assembly and could not for the life of me figure out how to adjust it. turns out the answer is: you don't!

[@1divemaster1]

Great explanation. Thank u much.

[@greaserleo]

The carb needs to be on its side not upside down to get accurate level of float

[@HTMR]

I forgot to mention that the "tit" should not be depressed. That is why some say it should be tipped on an angle.

[@oomrah9748]

Tipped on an angle how?

[@tofgof2917]

​@@oomrah9748you tilt the carburetor on its side, where the air filter side is pointing up. Then tilt the carburetor till the float starts touching the needle. And that's when you measure.

[@sPi711]

and the precise way​ to find the point where the float touches the needle is to blow into a tube attached to the inlet ; and the point at which you can no longer hear air is where you begin to measure the factory spec for float height. Then use the method shown above to verify.

[@mrfenderguy1]

How does a float on a 1970 ct70 or 74 z50 compare as far as float adjustment goes? Can same method be used.

[@HTMR]

Yes, it will be outlined in manual.

[@kiesuki1385]

this way can fix leaking fuel for any carburetors

[@joshsutcliffe6099]

And does the 1-2mm apply to all carbs?

[@HTMR]

General rule of thumb if you don't have the spec.

[@GAWRONTUNING]

nice thanks !

[@plusblood5101]

That is awesome video less0n

[@Ridendrty]

Nice.. thanks

[@brianconway2820]

The day I take advice from a lefty is the day I die.

[@olddanb1]

Loving the permanentand imbalanced twist you put into the float stop by bending in with a screwdriver on one side only, and REALLY loving how you used the delicate floats themselves to bend the stiff brass float hinge, instean of using two pliers on the brass itself. Tragic.

Thanks! Regards!

[@blackstephill1882]

Question my motorcycle would go around the block but just as I am about to get back to the house the bike just dies

[@blackstephill1882]

Help please

[@Nelis1992]

@@blackstephill1882 Okay and what do you do to get it running again? Or can you start it again right after it dies?

[@yallhatebaadddyoung7356]

Heck yeah

[@alangoodwin8423]

We need to refloat my carb float

[@RobCreswick]

Using too small a tube could show the height as higher than it really is, thanks to capillary action.

[@malexder0082]

I don't understand why you put the tube into the drain screw hole instead on the overflow tube on the underside of the float bowl. Seems easier and less chance of making a mess.

[@ogri48]

the overflow pipe is way too high on the inside mate

[@alangoodwin8423]

I am 12 and I am trying to fix me and my mum dirt bike

[@jayryan7473]

So just totally ignore the spring and plunger the tang sits on? I'm not big on leaving out an important part of necessary procedure. It's okay to learn how to do something before showing the world.

[@HTMR]

I forgot to mention that in the video.

[@etnica678]

👏👏👏

[@kylevanslyke6235]

I thought you weren’t supposed to adjust float while all the way down. Only on side barely touching

[@HTMR]

I did forget to mention that in the video. The "tit" should not be depressed.

[@choppergirl]

My float height is not right, and it's not adjustable. I did the clear tube test and the fill level is over the gasket. Do you have any idea. My idea is that the 1985 float is different from the all the rest. kzbin.info/www/bejne/r3-UiKOjbsSLqZY kzbin.info/www/bejne/nWfcZGV9rJp7gZY My bike will idle on full choke, then if I twist throttle it will stumble, then if blast past that it will run fine.. on choke of course. But it's next to impossible to get past the stumble. The fuel level is definitely over the gasket height because it's leaking even with a new float bowl gasket on it.

[@vicamaral]

wrong wrong carb should never be level should be in an angle so there's no pressure on the needle spring plunger

[@TerrenceLP]

Get your carburetor cleaned up and back to stock specs. If you're not easily intimidated, tune away for power gains 🤌💪

[@peterschott1500]

If float is too high, you would bend the tab down not up.

[@yamahapraveen7878]

Pls tell tamil I can't understand your language