News

UPDATED KA100 CARBY SETTINGS FOR TILLOTSON HW-33A

Updated 20/06/2019
Tillotson Logo

TILLOTSON HW-33A

KA4 RESTRICTED
- Inlet Spring: 31 gram (8-9psi pop off)
- Lever Height: Top of lever flush with metering body 
JET SETTING
Low Jet: 1 hour & 10-15 mins
High Jet: 45-50 mins

KA3 UNRESTRICTED
- Inlet Spring: 31-37 gram (8-11psi pop off depending on spring)
- Lever Height: Top of lever flush with metering body 
JET SETTING
- Low Jet: 1 hour - 1 hour 10 mins
- High Jet: 1 hour - 1 hour 5 mins

TIP: A higher pop off pressure will generally require a richer setting on the low jet to give the engine enough fuel off the turn. As a result, due to the efficiency of the low jet circuit, this richer setting will deliver too much fuel in the mid range RPM causing the engine to feel sluggish. Therefore it is recommended to avoid using a very high pop off pressure.

Tillotson Logo

TILLOTSON HL-398A

KA4 RESTRICTED
Low Jet: 1 hour & 45 minutes (1 & 3/4 turn out)
High Jet: 45 minutes (3/4 turn out)

KA3 UNRESTRICTED
Low Jet: 1 hour & 45 to 55 minutes (Just under 2 turns out)
High Jet: 45 minutes (3/4 turn out)

Idle Screw
Screw in until the engine idles at 2,000 to 2,500 RPM, this makes starting the engine very easy.

Pop-Off Pressure
8 to 10 PSI

Metering Lever Height
Top of the lever should be dead-level with the Carby body.