Float height/weight?

Paddy said:
I wonder how important float hight really is ? Its going to alter with lean angle, acceleration and deceleration. In my world of bevel ducati's the float hight is given as an exact but TBH the front carb is angled at about 45 degrees and leaning on its side while the rear is horizontal and level.
what is really important is the fuel level in the emulsion tube which being in the centre of the float bowl (ish) will remain pretty constant, for this reason some sort of manometer would be the answer, some Dellorto's do have a drain plug that can be used to attach a manometer tube.
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Why don't you drop it by 2mm and see how quickly you can hole a piston at WOT? :D

Fuel level in the emulsion tube is directly connected to float height.  Float height is the easiest thing to check half-accurately while the carb is off the engine, so gives a close-to-ideal setting for the ensuing fuel level.  Having all carbs in the same plane is a definite advantage, having them at different angles opens a new can of worms... perhaps it may be an advantage to use manometer tubes in that case.

Ideally, the fuel level should stay constant at all times and there should be no sloshing around in the float bowl while cornering or accellerating.  The main reason fuel injection is so much better more precise than carbs!

piet
 
I was tuning a set of Carbs with a O2 meter and out of interest I changed the float height from the min to max and read at each setting.
Made a considerable difference, enough that on seeing the O2 reading in isolation you would have changed the pilot jets at a minimum. In the same teas I also disabled the pump jets and compared with and with out. Big variation with peak over in riching when in and large lean out when disabled. I have now bought a range of pump jets and and will test smaller pump volumes 2.5-3 ml with smaller jet sizes to give the same duration. should be interesting for those not going to Muki's 
 
There are hundreds of pages,net wise and mods around to adjust the timing strength volume of FCR accelerator pumps.Even down to videoing them to calibrate via frames per second on the camera.Helped 100% on my Husky,std had a squirt time way to much.Reduced by drilling a bleed jet in the carb from 0.35mm to 0.75mm.And then no more cough and stall.Be a productive thing to do Will.The FCRs tend to be very big in there application 37mm on my 250,41mm on the 450s.
 
Agree piet. I was just thinking the question was about float height/weight and of course one dictates the other  so straight away you have variable float heights but the level in the emulsion tube is not a variable ie: the float height should be adjusted to suit it..Therefore you manometer is a lot more accurate than setting a float height and finding the height is wrong for the weight. we should be talking setting fuel level not float height really.
 
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