Mikumi 18mm carb float adjustment - 2006 Diamo Cruiser VTwin 250

remove the carb, take off the bottom float bowl on the carb. Then while holding the carb upside down, you want to set the floats level. You will have to bend the little tab on the float needle to do so.

Carbs off and upside down measure the distance between the top of the float and the part of the carb where the float bowl gasket goes ,with the gasket off.there will be measurement in the manual and it will be plus or minus a millimetre.you adjust it by bending the metal tag that pushes on the float needle that's joined to the float , unless it's made of plastic then it can't be adjusted.

Float height is not related to time. This is a very technical area (carb adjustment) best left to the pros who have the skills, knowledge and equally important, the measurement tools to properly adjust a carb. Time is an entirely different thing.

The Float adjustment usually involves carefully bending a tab against the needle valve where the fuel enters the float bowl. Since the float, "floats", there is no external adjustment. The float should close the valve at a specific height, and open as the fuel level drops, thus controling the level of fuel in the bowl, which in turn controls the amount of fuel being ingested by the carb. As for cleaning, any over the counter fuel system cleaning additive will help with that, from any auto parts store.

float level is usually per bike. you can try to start at 16mm give or take 1mm this is the setting for a 1989 kdx 200/220. it is measured from the bottom of float to the mating surface just touching needle. the best way is a service manual or owners manual should tell you. You can play with them a little by changing the measurements you can richen or lean the fuel a little, example 18mm would be leaner, and 14 would be richer.

is the 22 mm carb new or used? sounds like the needle is stickingor the float is bad?

it may be due to a few things like:
1. The needle valve or its seat is worn. You have to change it as a set. This involves opening up the carb.
2. There may be some debris or varnish between the mating surface of the needle valve and seat which also requires opening up the carb and cleaning with carb cleaner.
3. You carb float level setting may be incorrect. You have to know the float height from the manual and then have it adjusted. There is usually a small metal under the float which is used for float height adjustment.
4. Your carb float may be stuck and this usually happens when the bike is on its side stand and not used for a long time.

With the float bowl off and the float assembled in the carb, hold the carb on it's side with the needle and seat hinge upwards.

Set the float height to 0.630" to 0.670" (16-17mm) from the "bottom" of the float to the gasket surface where the float bowl gasket seal is.

These carbs are notorious for leaking past the needle and seat even when the float level is set correctly. They make a tool for refurbishing the seat in the carb as it is not replacable but the tool is very expensive for what it is and the amount of use will get out of it ($100). Sometimes I've set the float level an additional 1mm low (18mm) to put more pressure on the needle if it does leak. Good Luck!

adjust the tab upwards just a tad should be 19mm from the surface off the carb to the top off the float with the float just touching the inlet fuel valve basically with carb at an angle

You describe a problem with either the float or the float-needle and seat. If the needle is not seating then the gas flows past it. If the float has a pin-hole leak, then it will fill with gas and sink.
On some bikes you can remove the carb bowl without removing the carbs. If so, slide the hinge pin holding the float to one side and remove. The float will drop straight down. Catch the needle since it is now loose. Unscrew the needle seat with a socket.
Clean all metal parts in carburator cleaner...do not get carb cleaner on any rubber part. Shake the float and listen for gas inside or see if it floats in water.
Test the needle seal in the seat by blowing gently thru seat. Needle must seat completly with very little pressure holding the needle in the seat.
Re-assemble with new bowl gasket if damaged. A carb rebuild kit ($35) might be available for 1973 carb and contains all new parts instead of cleaning. Kit might even contain new float and float adjust guide.
Avoid adjusting float level if re-using the old float. If using new float, temporarily install old and measure distance to carb body. Install new and match this measuremnt. Bend tang to adjust.

Good luck,
Techjoel