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Brass Air/Fuel Screw Cap

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I am about to pull off the brass cap to get to the air/fuel screw on the carb.  I am going to drill into it and use a screw to pull it.  Does anyone know where I can get another one if I mess it up?  They don't come with the carb kits.

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Generally, you cannot buy a brass plug/cap.

Some bikes, you can remove the float bowl, and pop it out from behind with a punch and a light tap. Others, you first drill a tiny indentation, then use about a 3/32" drill bit (new, nice and sharp) and carefully dril in to where it just pierces the plug. Then a sheet metal screw in it just until it 'bites', then grab the head of the screw with pliers and it will pop right out.

If.. we knew make/model/year, we could point you to where you could buy an extended fuel screw to make adjustments a snap.

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1 minute ago, molloyjp said:

1981 Yamaha XT250.  Do they make extended fuel screws for this bike?

No, but it is easy to get to on your bike.

I've read your other threads. You need to get teh carb properly cleaneed. You cannot adjust away a gunked up carb. Pilot jets are very precision parts and cleaning rarely works. Replace with a new one once the carb is 'as new' clean.

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I cleaned the whole carb and replaced everything with a kit but did not remove the fuel screw.  That is the only thing I did not replace and clean.  I will pull the cap and clean/replace the fuel screw tonight.

Should I use regular gas or premium?

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BEFORE you remove the old screw, note EXACTLY where it is set. That mean look at the slot and write down EXACTLY how much you have to turn it to GENTLY close it. It might be exactly 2 turns. It might be 1 and 1/32 of a turn. You may want to make a drawing of it to get that last bit of a turn just right.

Are the parts you used OEM or aftermarket? I find the aftermarket parts (especially when it comes to jets) have widely varying quality control. some are good, some have been utter junk. I only use OEM jets.

Be sure to use the new oring and any other fuel screw parts you got. When the bike is back together, ride it for at least fifteen minutes. If the idle is not perfect, turn the fuel screw one direction a/8 of a turn and ride for a few minutes, if it idles better, try another 1/8 of a turn. If it gets worse, return the screw to the ORIGINAL position and try it the other way. You should not have to turn it more than 1/2 a turn (if at all) for a perfect idle.

Your bike is fine with regular gas though if you go to a good station with name brand fuel, often the premium has detergents that help keep the fuel system. E10 or non-ethanol. No E85. If the bike is going to sit more than a few weeks, add Stabil or other fuel stabilizer and ride fiove minutes to ensure it is distributed throughout the fuel system.

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