float level

[bowtie4511]

u stand the carbs on end to adjust float level. once that is done & u lay them down flat, upside down, is the top of float supose to contact the carb?

 

[dan filipi]

That's a very good question and ya know, I never paid attention to whether they contact or not.
Maybe someone has a rack apart can take a look see?

 

[bowtie4511]

i have them off still cause i am needing 1 more oring. i set them just like u said in ur posting. once i get the other oring i can turn them upright & fill them with fuel & see if they shut off.

 

[slabghost]

If memory serves I think the float needles have a spring pin on the end that contacts the float allowing them to compress a little with the weight of the floats on them. I'm guessing this is for two reasons. 1 limit the amount of force that the float can apply to the needle seat. And 2 to limit the possibility of changing the float setting when cleaning the carbs.

 

[flash2002]

I always thought the spring in the float needle was to absorb the vibration so not to damage the needle point.

 

[Bobo]

u stand the carbs on end to adjust float level. once that is done & u lay them down flat, upside down, is the top of float supose to contact the carb?

The top of the float should not contact the carb body, if that's what you mean. Other than the swivel pin that holds it in place, the only other point of contact should be where the adjustment tang of the floats presses against the bottom of the fuel inlet needle, I believe.

 

[bowtie4511]

i adjusted the carbs when standing on end to 15.5mm. but when laid upside down th top of the float contacted the top of the bowl. i finally got a acc pump oring so i could procede again. when that carb's float bowl was on i flipped right side up & filled fuel lie with fuel. no leaks. i put on and have synced the carbs & it is running better & smoother than it has ever had. so far so good. i am on my first tank of gas to check milage.

 

[bowtie4511]

ps i think the floats might be contacting the top of the bowl cause of them being spring loaded needle seats.

 

[dan filipi]

ps i think the floats might be contacting the top of the bowl cause of them being spring loaded needle seats.

I agree.
Afterall, something needs to be a stop for the floats.

 

[Bobo]

ps i think the floats might be contacting the top of the bowl cause of them being spring loaded needle seats.

I agree.
Afterall, something needs to be a stop for the floats.

With all due respect, Gents, I'm quite sure that just the adjustment tang's contact with the inlet needle's bottom is that stop.

 

[slabghost]

I always thought the spring in the float needle was to absorb the vibration so not to damage the needle point.

have you ever tried to vibrate something in liquid. Many other carbs do not have the spring pin or suffer any damage from vibration.

 

[bowtie4511]

i have the carbs back together & had running. ran great but found a leak at the acc pump. have them off again to fix that. only thing wrong was that the gas milage dropped from37 to 33. i am wanting to lower the float level some cause i know that will lean it out some & be better on gas millage. how far can i lower it? i set it at 15.0mm standing carbs upright. i thought it was to high from the begening because of the float hitting the top of the bowl when turned upside down. thanks ernie

 

[dan filipi]

I'm thinkin you have bad float needles, maybe inferior aftermarket ones.
If you can wait, I have a untouched set at home I'll pull the float bowls tonight and check on the float height when upside down.

 

[bowtie4511]

kool, thank u.

 

[Bobo]

i have the carbs back together & had running. ran great but found a leak at the acc pump. have them off again to fix that. only thing wrong was that the gas milage dropped from37 to 33. i am wanting to lower the float level some cause i know that will lean it out some & be better on gas millage. how far can i lower it? i set it at 15.0mm standing carbs upright. i thought it was to high from the begening because of the float hitting the top of the bowl when turned upside down. thanks ernie

Float height does not affect the lean/rich mix of fuel and air, just when fuel is allowed into the carb bowl. If all your jets are clean, you'll want to adjust the pilot screws first to the factory/manual spec and then synchronize your carbs. That'll give you a baseline performance to tweek from.

 

[bowtie4511]

i have already done the idle jets adj. & synced the carbs. & it is to my belief that float level does affect rich oa lean some. not as much as changing jets.

 

[bowtie4511]

p.s. the float level idle jets & sync was the only adj that i did. 2 carbs were 2 turns out & the othe other 2 were3 1/2 turns out. the carbs were synced before i did this & then after i did this. when i set the float level after replacing the needle seat, i had to adj quite a bit to a higher float level according to the flotr measurement. so that is the biggest adj i made that in my book would be to the richer side cause of having a higher float level it is easier to suck the fuel out of.

 

[dan filipi]

I hope this will help answer some questions.

This is what the float looks like in relation to the carb body when adjusted to spec, the float sits even with the carb body and the spring pressure of the needle's center pin will keep the float at this height even if the carb is layed upside down.

When depressing the float against the spring loaded needle valve, the float will contact the carb body before (what appears to be) the center spring loaded pin inside the needle valve is fully depressed.

This tells me it's important for the needle seat to make a good seal and in the case of questionable seats even more important to bench test and verify gas level actually in the bowl.

As a side note here,
This carb rack is very gummed up with old fuel.
When I first opened it the center needle pin was stuck out.
I could totally see how the pin could get stuck IN the same way.
After shooting the pin with PB Blaster it freed up but it's still a bit lazy.
Could this be the problem your having or something similar?

You are right btw. If float height is too high it will indeed run too rich, same if float is too low, too lean.
Float height is fairly critical to the right mixture though not the last word.

 

[joedrum]

dan when i tried to make pic big it gave me a little slit window to look at.... wide but only 1/2" tall

 

[dan filipi]

dan when i tried to make pic big it gave me a little slit window to look at.... wide but only 1/2" tall

Yeah, the zoom feature doesn't play nice with full size gallery images, only works to zoom attachments.
I can't imagine needing the image larger than it is anyway.