Jetting Amal Mk1 Concentrics for Vincent Twins, and Singles

(These specifications are for 32mm 932 carbs)

I will show jetting specs here that I have used for 1,000cc Vincent Rapides, and Black Shadows using Mk1 standard cams, and low compression. Then for those with hotter motors, I will include the jetting I use on my 1,164cc Big Bore motor using Mk2 "Lightening" cams, and 10:1 compression. These numbers might not be absolutely correct for all Vincents, but it will offer a very close base line for you to fine-tune by.

Jetting for Standard Rapide, and Shadows:

Slide=3.0

Needle Jet=107

Needle=(2) Bands, Top clip for Hi-Elev., and Middle clip for Lo-Elev.

Main Jet=220 (Hi Elev), and 230 (Lo Elev)

Pilot Jet=#30

Mixture Screw=Between 1 and 1 1/4 turns out for fastest idle speed

Float Level=.080" below edge of bowl

Feed Nozzle=Cut away the entire back half (downstream)

Timing=34 Degrees Full Advance

Spark Plugs=NGK B8EGV Gold Paladium Racing Plugs @ .020" Gap

Jetting for My 1,164cc Big Bore Hi Compression motor:

Slide=3.0

Needle Jet=107

Needle=(4) Bands, Middle clip for Hi-Elev., and Middle clip for Lo-Elev.

Main Jet=250 (Hi Elev), and 260 (Lo Elev)

Pilot Jet=#35

Mixture Screw=Between 1 and 1 1/4 turns out for fastest idle speed

Float Level=.080" below edge of bowl

Feed Nozzle=Cut away the entire back half (downstream)

Timing=34 Degrees Full Advance

Spark Plugs=NGK B8EGV Gold Paladium Racing Plugs @.020" Gap

CONTACT INFORMATION:

James R. Mosher

(505) 466-7870

(505) 466-6066 fax