Drilling out jets | 356 Speedster, 550 Spyder, Replica, Automotive Community

I'm in the process of fine tuning my carbs by trying out different jet sizes/combinations.
A friend of mine gave me a box of assorted jets and some drill bits.

The table below lists the more common size micro drill bits available.
Most micro drill bits come in either mm or wire size

Main Jet Wire Size/"s Idle Jet Wire Size
1.35 n/a .50 n/a
1.379 54 .508 76
1.40 n/a .52 n/a
1.45 n/a .53 75
1.50 n/a .55 n/a
1.5113 53 .5715 74
1.55 n/a .60 n/a
1.5875 1/16" .6096 73
1.60 n/a .635 72
1.6129 52 .65 n/a
1.65 n/a
1.70 n/a
1.7018 51
1.75 n/a
1.778 50
1.80 n/a

9/17/0312:13 AM

Original Post

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I'm in the process of fine tuning my carbs by trying out different jet sizes/combinations.
A friend of mine gave me a box of assorted jets and some drill bits.

The table below lists the more common size micro drill bits available.
Most micro drill bits come in either mm or wire size

Main Jet Wire Size/"s Idle Jet Wire Size
1.35 n/a .50 n/a
1.379 54 .508 76
1.40 n/a .52 n/a
1.45 n/a .53 75
1.50 n/a .55 n/a
1.5113 53 .5715 74
1.55 n/a .60 n/a
1.5875 1/16" .6096 73
1.60 n/a .635 72
1.6129 52 .65 n/a
1.65 n/a
1.70 n/a
1.7018 51
1.75 n/a
1.778 50
1.80 n/a

9/17/0312:13 AM

Hmm...that table didn't migrate over very well.

Anyway, I hope you get the idea.

Dave

9/17/0312:18 AM

Former Member

Weber marks factory jets for FLOW, that is, a 150 main will always flow almost exactly sthe same amount. If you drill jets you may not even get the same flow on two of them. If you want to enlarge Weber jets, get Weber jet reamers or a set of oil furnace jet reamers.

9/17/0311:13 AM

Former Member

A jet reamer is great because you can get just the right size and they

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