Float height - So what REALLY is the stock equivalent?

[fzrbrandon]

Hi all,

I posted this up over on the Archives but want to get y'all's opinion also.

I've been looking all over for this and can't seem to find a clear answer. What is the stock float height supposed to be? I know the Clymer manual states 3.8mm - 4.8mm which if I understand correctly is a measurement of the fuel level (NOT float height). So the question is what would be the equivalent float height range (using 3.8mm - 4.8mm on one end of the equal sign). I've actually seen both 22mm and 24mm quoted as the stock float height. They can't both be right unless of course one is referring to 49-state and the other CA.

Thanks guys,
Brandon

[DEMORAL1ZE]

I have the same question...and can you post a link to your question on the archives

[fzrbrandon]

I have the same question...and can you post a link to your question on the archives

Absolutely. Here you go man:

http://www.fzrarchives.com/ipb/index.ph ... opic=44256

Brandon

[slayermd]

Well, I don't know if there is an exact number but the range is 20-24mm for the float hight depending on how rich/lean you need it to be.

[fzrbrandon]

Well, I don't know if there is an exact number but the range is 20-24mm for the float hight depending on how rich/lean you need it to be.

Yea, it appears that most guys seem to run either 22mm or 24mm. If I could just get whatever the equivalent is to the fuel level (3.8mm - 4.8mm) I think I'd be in good shape. As it is, it seems like I'm just flipping a coin. That sucks...

Thanks man!
Brandon

[slayermd]

Well, not gonna lie, Ive never even heard about measuring the actual fuel level.

[fzrbrandon]

Well, not gonna lie, Ive never even heard about measuring the actual fuel level.

There's some kind of funky tool that actually sits in the float bowl I believe. Not real sure though. But judging by the Clymer manual's low 3.8mm - 4.8mm figure I would say that it (the manual) is actually referring to the depth of the fuel in the bowl (aside from the fact that it actually says "Fuel Level" ). It's really odd that this isn't a common tidbit of info! Oh well, we'll figure it out...

[megaloxana]

24mm is recommended for a jet kit.

[fzrbrandon]

24mm is recommended for a jet kit.

Okay, but that still doesn't answer the original question which is what is the STOCK float height (as opposed to fuel level which is known to be 3.8mm to 4.8mm)? As far as 24mm being recommended for a jet kit goes, where does this come from? I've seen a pretty even split of 22mm and 24mm with a couple 23mms and even a 26mm thrown in for good measure. This is with a pretty wide variety of jet sizes, clip positions, pilot screw adjustment, airbox / no airbox, stock / aftermarket exhaust, etc. So obviously there are MANY variables to deal with here but it begs the question even more: Why would 24mm be THE recommended float height with a jet kit? Is it the same whether you're running 110s OR 130s? Hell, one of my bike's POs had 135s in the bike until I yanked those suckers out yesterday!!! That and the pilot screws being 5.5 turns out!!! Oh, and the float height seems to be about 19mm! What the hell? That's another rant though.

And yes, I did have a look at this (and it really doesn't help):

http://www.factorypro.com/Prod_Pages/prody02.html

Believe me, I spent the better part of my day at work trying to sort all this out (along with another few hours or so in the last few days) so I HAVE been trying to do my homework. I'm planning on going ahead and setting them to 24mm but I still would like to know what stock is.

Thanks,
Brandon

[modkingfzr600]

well there is no actual float height setting in mm from yamaha that i know of, however i can tell you exactly how to find out what the stock float height was pre-set to.

you need a short piece of 6mm " I.D" clear line, and the rest is elbow grease.

there is a line across all of the bowls of the carbs that is part of the casting.

factory fuel level is 3.8 - 4.8 mm above that line.

take the peice of hose and attach it to the drain nipple of one bowl, bend the tubing upwards so it is setting right beside the line on the bottom of the bowl.

open the drain screw a couple turns and this will show you exactly how much fuel you have in your bowls, in reference to the line on the bowls. start the engine and let it run for about 30 seconds , wait for the fuel in the tubing to settle.

then measure in mm how far the fuel in the tubing is above the line on the bowls, adjust the float needle "tang" to acheive the factory fuel level ( 3.8 - 4.8mm ) "above the line" and then at that point you can measure the float height in mm to get the factory float height. you're done.

[fzrbrandon]

well there is no actual float height setting in mm from yamaha that i know of, however i can tell you exactly how to find out what the stock float height was pre-set to.

you need a short piece of 6mm " I.D" clear line, and the rest is elbow grease.

there is a line across all of the bowls of the carbs that is part of the casting.

factory fuel level is 3.8 - 4.8 mm above that line.

take the peice of hose and attach it to the drain nipple of one bowl, bend the tubing upwards so it is setting right beside the line on the bottom of the bowl.

open the drain screw a couple turns and this will show you exactly how much fuel you have in your bowls, in reference to the line on the bowls. start the engine and let it run for about 30 seconds , wait for the fuel in the tubing to settle.

then measure in mm how far the fuel in the tubing is above the line on the bowls, adjust the float needle "tang" to acheive the factory fuel level ( 3.8 - 4.8mm ) "above the line" and then at that point you can measure the float height in mm to get the factory float height. you're done.

Hey Modking,

Thanks very much for the detailed response. I appreciate it. Based on what you're saying then, the Factory Pro page DOES actually make a bit of sense now. If Yamaha's stock level is 3.8mm - 4.8mm ABOVE the line, the middle-of-the-road would be about 4mm which equals 22mm on FP's chart. Close enough for me...

Thanks again!
Brandon

[slayermd]

Phhew. Glad that was settled.

Wiki anyone?

[fzrbrandon]

Phhew. Glad that was settled.

Wiki anyone?

Yeah, this would be a great addition to the carburetor Wiki. Speaking of which, it looks like it's off to a great start but still needs lots of stuff to be added. Slightly off topic, but I wonder what the protocol is for gathering information to add to it? I'd be more than happy to try and pull some stuff together.

Yamaha George,

What do you think?

Brandon

[jruponen]

Hi !

Your advise seems to be in accordance with Haynes´s and Clymers´s manuals.

I wonder how this 24 mm is measured. Is it a gap/distance between some levels in the floating chamber ? I found on my fzr the carbs up side it is 19 mm between washer level of the body and the bottom of the float. This bike jerks at 1000-2500 rpm especially on rough surfaces.

Does it get too much gasoline or is it starving ?

Regards, jarkko

[jruponen]

Sorry, for miss spelling !

Float level mesurement from bottom of the flot to carb joint level is 19 mm is valid the Carb up side down. Should this measurement be 24 mm ?

jarkko