Washers for carb needles

For shimming your carb needles you need to look for #4 washers. These have the following dimensions, listed in decimal, fractional, and metric sizes:

• ID = 0.1250" , 1/8" , 3.175mm
• OD = 0.3750" , 3/8" , 9.525mm
• thickness = 0.0400" , 1.016mm

If you can't find #4 washers, try to get an assortment that is close in dimension. Those with 2.5 - 3mm inside diameter, and not being too much larger than 3/8"/9.5mm should be fine. As always, it's better to get a few more than you need, rather than having to keep going back to the store.