Jetting Basic’s good bad and ugly

[GregMember]

1. IDLE: Set idle speed to correct r.p.m. by adjusting the IDLE SPEED SCREW. Turn The AIR SCREW to achieve the highest idle speed and best response. After this adjustment has been made adjust the IDLE SPEED again back to the correct r.p.m.

2. OFF IDLE to 1/4 THROTTLE: The SLOW JET and the AIR SCREW are most effective in this range. When you want a richer mixture use a larger SLOW JET or turn the AIR SCREW in. The opposite holds true for a leaner Mixture.

3. 1/4 to 3/4 THROTTLE: The JET NEEDLE is the most effective component in this range. Raising the needle by lowering the clip position at the top of the needle will richen the mixture. Lowering the needle will lean the mixture.

4. WIDE OPEN THROTTLE (W.O.T.): Changing the MAIN JET effects this range. Select the size which offers the best W.O.T. performance, then install one size larger MAIN JET for ideal engine durability.

NOTE: Not all Carbs have AIR SCREWS. Some have FUEL SCREWS, it is important to differentiate as to which one you have. This depends on the location of the screw on the carb. (looking at the center of the carb) If the screw is in between the cylinder and the carb body , it’s a FUEL SCREW, turn it OUT to get more fuel (richer) if the screw is in between the carb body and the air box, it’s an AIR SCREW, turn IN to richen it. As far as I know this rule of thumb is correct. Check with your dealer or manual if at all unsure. Note: most air/fuel screws should be set somewhere between 0.5 to 3.0 turns from seated, if it is outside this range you should look towards your slow jet.

Thanks to justXR.com

[Scott BattyeMember]

I can’t believe you thank XR.com for the info.
What about the hour I spent on the phone to you explaining how to jet your bike.

Bloody Diesel Mechanics!

[Mick DMember]

Rip it into him Batman!! He dishes out his fair share. Good work old son.(Don’t tell TB but your Karma just went up 1)

[GregMember]

Batman666 wrote:

Quote:

I can’t believe you thank XR.com for the info.
What about the hour I spent on the phone to you explaining how to jet your bike.

Bloody Diesel Mechanics!

Fathead you Butthead, what you told me was right, but it was hard to transfer all that dribble in to something other people could understand, I am used to working with you others are not, hence the picture

[StuartMember]

this will help sorting the IT now! thanks.

[Author]

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