Float height adjustment for Mikuni BST36SS Carburettor Suzuki GSX Katana

Simple motorcycle float adjustment. How to set the carburettor float heights on a SUZUKI GSX750F Katana Carby 89-97. Also for other Mikuni carbs with, flat type, black slides. May suit 88-89 SUZUKI GSXR750. How to for Mikuni BST36SS, Mikuni BST33SS, Mikuni BST40SS.

[@95Jester]

Thank you! I just did a rebuild, and had struggle with the float adjustment. My GSF400 now starts and runs just fine! 😀

[@commiebobo]

This works for the GS500E as well. I set it your way and checked the height, it was right on spec. Thanks, bike is running super well now.

[@MikMech]

Glad to hear. Thanks for the heads up .👍

[@ghostdog662]

Nearly identical setup to a 2000 Suzuki bandit 1200. Thanks for the video

[@msmmagnum]

Don't hear the phrase Tickady Boo enough these days, thanks for the simple and easy explanation cheers

[@MikMech]

Cheers Mate

[@terenceokeeffesmotorcyclestuff]

In the middle of doing mine on a '95 Daytona 1200, thanks, really helpful.

[@chrnielsen3025]

Great input. I think you have swopped the bowl lid of 1 and as the drain screws should point outwards for easy carb emptying

[@MFDOOMgr]

Same for Dr800, thanks

[@govnor1495]

Thank you, works on GSXR 1100 oil cooled

[@4g63tpowered]

Might get back to the ole gsxf750 now thanks mate

[@4g63tpowered]

What year is your bike? I'm thinking about a oil temp sensor but cannot find good location mines an 89

[@maximilianpaech1944]

Good Explanation thx! Similar to Mikuni BST 33

[@MikMech]

Cheers

[@chomper4x4]

Thank you MikMech.

[@anabelbecerra3056]

ok thanks for your help I'm gonna go try it out c if stays on

[@as-603]

Thank you👍

[@stephenharding7689]

brillian mate :)

[@joshsutcliffe6099]

Other than leaking what Will a wrong height cause as far as performance

[@MikMech]

It could run rich if it overflows. Or starve if it's too low and begin to run lean.

[@mhdi4024]

اكو ترجمه بالعربي شكرا لك

[@shineyboots]

First if all you wer doing a reading with the carrier not firmly in position then later the reading was 17mm. at the bottom of the float. Question is, Where is this reading of 14.5 supposed to be?

[@MikMech]

From the bottom of the carby to the bottom of the float. Should be between 13.6 and 15.6mm. 14.5mm is nicely in the middle. 👍

[@rasoulsadeghi8635]

This Carb is a real nightmare if starts overflowing petrol

[@brayseville8468]

thank you

[@MikMech]

You're Welcome.....

[@josiahgovender1855]

Howsit I really need to know how to remove the main jet

[@josiahgovender1855]

The one that you find under the big flat head in the float bowl

[@brianm9035]

That bowl is off the other side notice how your drain screw is not accessible

[@jeffpaxton9172]

You say the float is supposed to be parallel or 15 mm but doesn't the float angle change as you rotate the carby? So its suppose to be parallel with the carby at what angle?

[@MikMech]

The seam, or 'flat centre line' on the float is supposed to be parallel with the bottom face on the carb. To do that, you need to hold the carby upside down or at an angle so the float is fully seated under it's own weight. 👍

[@DarkIzo]

manual for the bst33ss says to set the carb upside down and measure from gasket surface to top point of float (protip, the highest point is marked by a little imprinted dot)

[@francoisbrand7464]

set buddies 92 750 up just like this at 15mm.. it still runs pig rich, fouling plugs - choke def not stuck / air filter removed. mix screws 2 turns out - what could it be? Pulling our hair out! I even went from 14-15mm to see if it was possibly a tad to high.. we are at sea level, new plugs -

[@MikMech]

Did you raise the main needle jet? Some are fixed height and some are adjustable due to emission controls. Sometimes cleaning the jet will remove part of it it making it run rich as well. Try it with your mixture screws at 1.5 turns out and slowly wind them out until you get snappy throttle response. If there is any lag in throttle response the idle mixture is off. Have you changed the exhaust or had head work done?

[@MikMech]

The float heights are fairly rough allowing a 2mm variation. 13.6 to 15.6mm (0.53--0.61 in) Being a US model, you will have 2 different sized main jets. cylinder 1,2 and 4 have a 105 jet, and cylinder 3 has a 110 jet (for cooling I presume). More fiddle information can be found at katriders.com a good forum for any Kat. Cheers.

[@francoisbrand7464]

hey tx for getting back - the bike is a friends in South Africa.. no work done, clock is on 8k miles! cleaned carbs, sure no head work was done. Spoke to him earlier and one chap said if the orings arent exactly the right size they can shear and leak fuel into bowls i guess. Ive done many carbs - never had sth run so ridiculously rich after a good cleaning / etc. Hes fiddling with it today - Ill prob hear back 2moro and update u.. those early 90s bikes are the bomb!

[@joshsutcliffe6099]

@@MikMech I've never seen different size jets in any the bikes I've worked on.

[@MikMech]

@@joshsutcliffe6099 G'Day Josh. Depending on where the bike was shipped, they had different sized jets. Also the year models varied in size. Same 36mm Mikuni Carb but different jets. IE: California models ran leaner for emissions. Probably because the needles are fixed position type. Here is a good link. www.cmsnl.com/suzuki-gsx750f-1995-s-e02-e04-e18-e22-e24-e25-e34-e37_model13711/partslist/FIG-12.html. Cheers

[@123lenny135]

Nice!

[@jeffmee763]

Hi would it be the same for a cvk carb thanks. Jeff

[@MikMech]

G'Day Jeff I checked them out, and they look very similar. I would start with parallel to the case and then use this method. kzbin.info/www/bejne/r3qckIF4mNWtpZY Let me know if it works. Cheers

[@miroslavpatche2705]

The rubber plug on the pilot jet needs to be loose or needs to be tight ?

[@laurieh]

Im doing this on a 97 1200 bandit and the floats aren't sprung...is this normal?

[@MikMech]

So the float needle has no slide inside of it? If that's the case then they should still work fine. They will still shut off the fuel when the bowl is at the correct height. It just means that if you travel a VERY bumpy road, it may flood or starve when the fuel is slushing around inside the bowl. The spring is really just a cushion. Imagine your bowls are full of fuel. You park on a steep driveway and the fuel collects at the back of the bowl and pushes harder against the the floats. The spring stops the floats from applying too much pressure and damaging the rubber tip of the inlet needle. : )

[@laurieh]

@@MikMech ah cool...appears to make it a bit harder to do the heights as i need to tilt carb at exact angle when needles are closed...will manage

[@Ricardoisaaac]

Excuse me, I know what model the carb is?

[@enoz.j3506]

Those float bowl drain screws are gonna be impossible to use,you have the wrong bowl on!

[@carlosagua1666]

If the line off the float bowl and the line of the carby are parralel, it will always be 14.5/15.5 mm? Or am I missing something?

[@MikMech]

You got it ! Works for this carby. Not so sure of other models though.. Cheers from Sydney Australia

[@carlosagua1666]

@@MikMech Hi Mik, it was no question. What I was try to say... the bowl is 1 piece (non adjustable) and the carby body (non adjustable) so without or with adjussting the needle if the floatbowl line is parralel with the line of the carbbody its always 14.5/15.5 mm. I like you video a lot, watched it already 20 times. Cause fuel is leaking in my engine of my 250 gsf bandit, oil has fuel in it. So i thought i should adjust the hight of the needle and bump in your video, appreciate your vids, Greetings from Brissi.

[@rhumphress]

Did you forget to put the brass needle seat in before setting the cage.

[@MikMech]

No it's in there. You can see the floats bounce on it. lol

[@russellclark1118]

I have a question about the float assembly Primarily the pick up should it be clear to blow through cheers in advance

[@MikMech]

Yes. it lets fuel into the float bowl. This is usually gravity feed from the tank with no pump. If there is a blockage of any type you may starve for fuel at full throttle.

[@anabelbecerra3056]

I got a question about my bike its 94 750 katana I had the carbs rebuilt on my bike but still seems like its not getting fuel cranks turns on then quickly dies got any ideas

[@MikMech]

Sounds like it's starving for something. Either air of fuel. No blockages in the air system? Remove air filter and try again. Have you taken off the fuel hose from the tank and ran it to see how fast it flows? Could be restricted. Look inside the fuel tank an see if there is rust or crap in there. Could be the fuel tank filter is blocked. If your bike has been on it's side stand for a while the floats may have stuck. A few taps with a screwdriver handle might fix that. It's a long shot that all four would be stuck. (Last resort) Hope this helps Cheers

[@MikMech]

Here is a good resource for the fuel filter diagram. katriders.com/wiki/index.php?title=File:Petcock_explanation.gif

[@anabelbecerra3056]

one more question I took off the pilot (fuel/idle air adjustment) screw, is it supposed to have a spring in it cause mine don't? two of them just have o-ring, and the other two have o-ring and little washer

[@MikMech]

No Springs in your model. Should be a snug fit. I think the 88 and 89 did, but definitely not 1990 onward. (1990-1996)

[@anabelbecerra3056]

ok so ill be good just with oring in it

[@MikMech]

Yes. 👍

[@anabelbecerra3056]

ok the adjustment is 1.5 turns to start with right

[@MikMech]

You are correct. :)

[@jameswan670]

Hi. Do you know size of diaphram?

[@MikMech]

? Are you talking about the top diaphragm? Try Here www.manualslib.com/manual/384803/Suzuki-Gsx-F-750.html