53 ford jubilee carburator diagram i need to know if a 1953 ford jubilee has a main jet or if you just adjust til it is not too rich or lean

Hey Errol, Proper carburetor jetting can ONLY be obtained by reading the spark plug..This is NOT something an amateur can do..You need to know how to tell if the timing is too advanced, if the timing is to retarded, (two stroke - how to tell if your oil/fuel ratio, is correct -how to tell if it is too lean, how to tell if its too rich)... how to tell if the fuel/air ratio is too lean or too rich...when the spark plug is black, you have to be able to tell the difference between "oil black" and "rich fuel black"...
...now, if you can do this.. tell me what motorcycle this is about.. why do you need to know about jetting.. PLEASE give me more details... reply on here...

if the carb is fairly old the vibration makes the needle bang aroun the hole of the jet, thus making it larger and richer over time.
Ill try for that height about 3-4 numbers leaner... but be carefull!, if youre rich (gasoline term!)and go higher (altitude i.e. to a mountain) the only problem is that the engine will waste fuel, and a little black smoke... BUT if you are lean (or close to lean-of-peak) and go lower (altitude i.e. close to the sea) you can go dangerously lean and can make a hole in one piston or destroy the engine due to detonation and preignition.
just go 2 numbers, and if going to the beach, re jet the carb.

Ok most likely cause for this is jetting (Carbi) and or the air / fuel mix screw set to rich - Well done for noticing though as no where near enough people read their spark plugs and make adjustments - they normally wait til bike don't work before researching?
Simplest and first option would be turn in your air/fuel mix screw quarter to half a turn in (clock wise) this leans the fuel mix slightly
Second option if still not helping from just screw adjustment is put the mix screw back to where it was before and change the pilot jet to a smaller size - the pilot jets have number stamped on them so once you have yours out look for the number and just buy new 1 or 2 sizes smaller (they only about $5 each) then of course go back to fine adjustments on your air/fuel mix screw to find the correct balance
You will very quickly know if your setting is to lean as result of adjustments as you will get back firing when rolling of the throttle if becomes to lean
jetting and air fuel mix adjustments can be annoying sometimes as you may need to go up a bit then down a bit then up again but take your time do very minor adjustments then check results and my tip is only ever change one thing at a time then record the change then test and record the result if you dont you will very quickly forget what you did, not know what to reverse if result was poor and if result was good you won't know exactly what made the improvement.
good luck mate regards Jamie

Tough question as you need to read the plugs after riding to determine to lean or to rich but normally two sizes up on the pilot jet and 1 size up on main would be good place to start if you get heaps of popping or back fire when deceleration your to lean so bigger pilot jet required
personally I would just fit the system and see where its at before you change jetting and realistically it would only be the pilot jet if adjustment needed - the main jet is pretty much wide open anyway

You have a mikuni carb. there are curcuits to the carb. the first that works from idle to 1/4 throttle is the pilot cicuit, from there you transition to the needle jet/and jet needle. That controls the 1/4 to 3/4 throttle and then the main' jet which controls WOT. you may have a air screw that would be before the throttle plate if it is after it is a fuel screw find the factory specs for the jet sizes and make sure all is correct. if not you isolate where the problem is and correct in a rich or lean adjustment' I race yamaha 2 stroke road racing bikes, it is not an easy task sorry to complicate you so much

Your Sportster is an air cooled engine. If it's overheating, you got some serious problems.

First, check your oil level and make sure you've got plenty of oil in the bike. With the engine running and on the side stand, pull the oil fill plug and look into the tank. Shine a flashlight in there and make sure your oil is flowing. You should see the oil flowing back into the tank.

If that's alright, your carburator or fuel injection is running too lean. A too lean mixture will cause the engine spit back through the intake and run too hot.

If it's a carburated bike, you need to go up on step on the slow speed jet and raise the needle about 0.020" to richen the low speed and mid-range mixture. You may even need to richen the main jet up one step.

If the bike is fuel injected, you need to take it to a dealer and have them make the adjustments on the fuel system. The fuel to air ratio should be no higher than 14 to 1, preferrably 13.5:1. Anyone with a exhaust gas analyzer can check this for you. A dyno tune would be a good investment.

Good Luck
Steve

Usually an adjustment by itself will not do the job, the sise of the main jets must be increased. Normally 2 sizes larger is a good place to start. Install the jets, ride the bike, look at the spark plugs, white plugs is too lean the jet needs to be bigger, black sooty plug too rich jet is too big, medium to dark brown plugs is good mix. Pay attention to how the bike runs, this is more important than plug color, if it revs up good and runs good it is alright, too lean will make the pipes turn red( glowing red) right at the junction with the head, do not ride with a too lean condition it will overheat the engine, and can burn the pistons.

Looking at the front of the carburator, at the base of the carburator you will see 2 screws with a spring on each. 1 on one side, 1 one the other.

a four stroke will pop and backfire under decelleration when it is lean, or not enough fuel. (Jetting too small in the carburator) But, look at the spark plug for color, white is too lean, black is too rich, and chocolate is just right. Make sure the air filter is good and clean. And lastly... have the valves been adjusted?

use the air and gas flow adjustments on the side of the carburator to adjust the rich/lean flow of gas. there is a srew on each side of the carb to adjust one is for air the other for fuel. the one on the driversside is for the fuel and the one on the passenger side is for air. you have to turn them slowly til you get the desired results