wet float vs dry float levels

[onspeed]

I've noticed that setting my dry float with the 1.125" gap does not result in a 17mm wet float level. Any reason this would happen other than a bad caliper? I assume I should adjust based on wet float measurements rather than dry?

 

[maleko89]

Do you cycle key on and off to make sure bowl is full and no bubbles in your fuel level tool? How did you measure dry level? I measure with caliper as far out as possible away from hinge pin.

 

[onspeed]

Yes, cycled the key off/on. Measured as far out from the pin as well. I'm currently at ~17-19mm wet float, and my dry float measurement is much smaller than 1.125".

Only thing I can think is that my caliper is not accurate...

 

[MaxMidnight]

Only thing I can think is that my caliper is not accurate...

Unlikely - try measuring a metric drill bit which will be slightly smaller than the nominal size.

 

[onspeed]

So caliper is accurate. Rechecked wet levels, just in case my bike wasn't level yesterday or something but same results. My left side carbs are set to about 1.01" dry float measurement to get a 16-17mm wet float. My right side carbs are around 1.10"-1.11" dry float for the same wet float.

Qualitatively, my left side floats are just about horizontal when looking at them with the carb inverted. Right side have a slight angle upwards. I find it strange that both left side is off... but I'm certain I made no errors in my wet float measurement this time.

Thoughts?

 

[dannymax]

Are the seats pressed into the chambers the same distance?

Are all four needles the same length?

 

[wildweasel_pt]

Aren't the floats hinges bent or something?

 

[sdt354]

I spend minimum time setting dry levels. I line the circle in the casting up to the float. Wet check on a level table with the carbs split in two's, works best for me. Easy adjustment access. Time saved, accurate float heights.
+1 to seat heights being different sometimes. And, making dry setting just a quick starting point.

 

[95spfldmax]

Are the seats pressed into the chambers the same distance?

Are all four needles the same length?

unk:

you da man!!

 

[onspeed]

Seat heights might be different, but I don't see why that would affect anything since the dry measurement is taken using the float and the carb casting as a reference point. Different seat height just means the bend in the float tang will vary from carb to carb, but the relative position of the float in relation to the carb body should be the same.

 

[[email protected]]

Seat heights might be different, but I don't see why that would affect anything since the dry measurement is taken using the float and the carb casting as a reference point. Different seat height just means the bend in the float tang will vary from carb to carb, but the relative position of the float in relation to the carb body should be the same.

If the bend in the float tang is different then, you are going to have a different dry measurement.

Think of it as you are reaching for the ceiling. Your ceiling is the seat, your hand is the needle. If you have 8'-6" ceilings, you may just barely touch it with your fingers. If the ceiling is dropped lower (if the seat is not installed as deep into the carb body as others) it will be much easier for you to touch the ceiling (or close the seat with the needle)

Dry level measurement is a ball park reference. A wet level check is reality.

 

[onspeed]

I think a more accurate analogy would be that you're reaching towards the ceiling, standing on a ladder, trying to maintain a constant gap between your hand to the ceiling. If you go up a rung on the ladder, you will have to bend your elbow to keep that constant gap. That's essentially what the float is doing in the carb? Fuel level needs to be ~16mm below the mark at the middle, so when the fuel is about 16mm below the mark, the float should float and close the needle. The float should always be floating at that 16mm point, regardless of seat height. The way I see it, if the gap from the top of the carb to the float is smaller than normal, then my float won't float until the gas fills the carb more which should result in a higher wet level? Why is this not happening? In my ladder analogy, the dry measurement we take is that gap to the ceiling, the rungs are the seat height, and the bend in the elbow is the float tang.

Am I thinking of this the wrong way?

 

[[email protected]]

I see how your analogy makes sense but that is not the reality here.

If you set the floats dry at the typical 16-17mm and the seat protrudes into the float bowl more than normal, your wet level will be low. You would need to lower the dry setting to increase the wet level. Vise versa for a seat that is installed deeper than normal.

Sent from my SM-G900V using Tapatalk

 

[onspeed]

The only thing I can think of is that the seat is so far out, the range of motion the float needs to close the needle is very small, so that by the time it starts to float at the 1.125" setting, the needle closes before the float bowl has a chance to fill to it's capacity. So the float doesn't completely "float" before the needle gets shut due to the longer seat height?

 

[Ryansmith]

The only thing I can think of is that the seat is so far out, the range of motion the float needs to close the needle is very small, so that by the time it starts to float at the 1.125" setting, the needle closes before the float bowl has a chance to fill to it's capacity. So the float doesn't completely "float" before the needle gets shut due to the longer seat height?

I've have the same problem, with my carbs. Did you come up with what is the problem. I noticed this post was along time ago.

 

[Vinmax]

Could it be.......... that the floats may 'float' a bit differently. Going by dry measurements, the floats all look the same and measure the same. But once wet and floating, if one float, floats a bit higher (because of being a bit more buoyant), then it will be at a different level than the dry measurement would suggest.
Vinnie

 

[Traumahawk]

I have a question, I wonder if a pump could be rigged up to the carbs, that way the wet float level could be checked and set on a level bench......instead of having the carbs sitting on the bike?

 

[Vinmax]

Probably don't even need a pump. I made up something my self a long time ago when I was testing/tuning my ZX9R. I used a hanging bowl like this (I just used some makeshift parts but it same out just like this) to keep fuel flowing to the carbs while I had the tank off the bike;
https://www.wemoto.com/parts/picture/sq-ms029

 

[maleko89]

Probably don't even need a pump. I made up something my self a long time ago when I was testing/tuning my ZX9R. I used a hanging bowl like this (I just used some makeshift parts but it same out just like this) to keep fuel flowing to the carbs while I had the tank off the bike;
https://www.wemoto.com/parts/picture/sq-ms029

I have pretty much the same thing, works great! Mine's from Motion Pro.

Mark