Brand new carb broken? By curiousgeorge (Read 1,000 times)

[curiousgeorge]

So i just got my new carb, i opened it up and put a new size 80 main jet in it, closed it. Then i installed need fuel and vac lines to my scooter, i took the old carb off, put the new one in and tried cranking it.....it wouldn't start up, i kept trying but it wouldn't start. I took out the new carb put the old one back i. And it worked fine.....can anyone help with this problem?

[richardthescooter2]

What size jet was in the old carb?

[curiousgeorge]

Not sure, it was the standard, size small jet that comes in stock 50cc carbs, could it be a problem if the fuel bowl O ring os not seated properly?

[Alleyoop]

If the bowl cover is not sealing it would be leaking gas from around the bowl. Did you connect the Fuel Line and Vacuum hose correctly. If so then turn the Fuel Ratio Screw CLOCKWISE until it stops and then turn it Counter Clockwise 2 1/2 turns that should be enough for it to start and run pretty good.
Can you take a picture of the Carb Area with the hoses so I can see if everything is Okey .
Alleyoop

[curiousgeorge]

Alleyoop this is a picture of the new lines in and the old carb put back in. The scooter works with the old carb but not the new new one. Maybe i didnt crank it enough when i put the new one on?

[Alleyoop]

Well if you connected everything the same on the new carb then it should work. But remember it takes a bit to fill the bowl up with gas because it is empty. What you can do is like I said about the Fuel Ratio Screw and it also may be that the IDLE SPEED screw is either to open or to closed. Take a picture of the new carb by the butterfly like this:
Alleyoop

[curiousgeorge]

Alleyoop i tried putting it back on and messed with the idle speed and cranked it more and it started! Thatnk you sooo much for all your help. I am about to adjust the air fuel ratio now

[Alleyoop]

Great, sometimes the IDLE SPEED screwed in to much which opens the BUTTERFLY to much and to much air gets in and not enough fuel. Or the IDLE SPEED is NOT SCREWED down enough and and the BUTTERFLY is completely closed and in that CASE NOT ENOUGH FUEL can get sucked in.
Alleyoop

[curiousgeorge]

Just wondering, i followed the instructions of your adjusting the air fuel ratio but my rpms take forever to go back down fter i snap the throttle.

[Alleyoop]

It is TO LEAN, richen it up a little more, REMEMBER ONLY 1/4 turns on the screw and WAIT about 10 second so the motor adjusts to the new FUEL RATIO mixture.
Alleyoop

[curiousgeorge]

Got it tried some more and it still doesnt come back down promptly.

[Alleyoop]

HUMM, did you change the main jet or is it the stock jet. If you changed the MAIN JET to the bigger one THEN try LEANING it because now it is getting a lot more fuel in the mid-range than before. So turn it CLOCKWISE 1/4 at a time and after each 1/4 turn Hit the throttle and see if it acts better.
Alleyoop

[curiousgeorge]

Ok will try that, but just so you know i took it for a spin and accelerating it was pretty jerky and wouldnt go past 27 on the speedometer :/

[Alleyoop]

Well did you change the MAIN JET?
Alleyoop

[curiousgeorge]

Yes i installed the new 80 main jet for when the uni filter gets here.