What does each s***w on a carburetor do and what is the best way to adjust for a bogged down motorcycle?

Question

I have and older Honda Motorcycle and it isnt running right, I broke down and cleaned the carb but now I need to adjust it so it runs right?

Answer 1

if the s***w is on the air cleaner side its air adjustment if its on the other side its fuel adjustment. idle speed is a rather large thumbscrew cant miss it. since you removed the carbs and cleaned them they now need to be synchronised. the tool is about 100 dollars to purchace. I prefer murcury gauges they are more acurite. you can use dial gauges though,which are safer for an inexperiebced person like yourself.basic rule of thumb turn s***w in till lightly seated turn out 1 and a quarter to one and a half turns. adjust idle to about 1000 to 1100 r.p.m.  good luck!!!! easyer to show ya than tell ya. could tell ya better on the phone live.602 718 2429  oh yeas if ita a multi carb bike gona need a long angled screwdriver to reach the synch s***w.

Answer 2

If you haven't messed with the screws on that carb, then it should still be set to where your bike was running right.

If the bike wasn't running right, and you cleaned the carb and it still isn't running right and you didn't mess with the mixture s***w, then you have something else going on.

Change the plug (s), check the rubber boot that runs from the carb to the air filter box, make sure it isn't dry rotted and cracked, check to ensure the pitcock isn't partially clogged with rust or other junk from inside the gas tank (Pitcock is the on/off dial coming out of the tank into the fuel line)

Change the air filter.

Seat the mixture s***w.. it will normally be the bigger of the two screws. (the idle adjustment s***w is normally the smaller of the two, and has a spring on it)  Seat it by turning it until it is all the way in, now back it out 2 1/2 turns... this will normally get it in a position that the bike will start and run and is a little to the rich side...you would rather it be a little rich than lean, rich isn't as hard on a motor as lean is. If the bike starts up and runs clean...ride it up and down the road for a little while...then go home and pull the plug. If it is white richin the mixture, if it is black lean it out a bit...you only want to adjust 1/8th to 1/4 turn at a time.

If the bike doesn't start up and run clean...lean it out a little until it throttles crisp with no bog.. then test ride it and check the plug.

Clean the plug, then ride the bike again... check the plug again and repeat this process until the plug comes out and is not white or black, but more of a brownish color.

You said "Carb" so I assume you mean it only has one? This should be an easy set for you only adjusting one carb, if it has 4, or 2...more than one, you may want to take the bike to Honda and let them do it, you have to sync those carbs, and they all have to be perfect or you will feel it surge and lag between cyclinders at low speeds. Unless you have a vaccum gauge... then you can sync them with no problem, although for your bike I don't know what the readings should be.

Answer 3

You have a fuel/air mixture s***w and an idle adjustment s***w.  If it is bogging down check the spark plug and see if it is black.  If it is black change it and adjust your fuel air mixture s***w out a 1/4 turn at a time.  s******g it in raises the needle and allows more gas to flow to the motor, s******g it out lowers the needle allowing less fuel to flow to the motor.  This is only true at low to mid throttle.  Keep adjusting and checking your spark plug till it is a nice golden brown color.  If it starts turning white it means you need more fuel.

Answer 4

one s***w is for air the other is for fuel. Get your hands on a cylmer manual it will tell you the optim turns for each. If its bogging down you may have a reed , jet or float problem.