Autolite 1100 Jetting change

[Anonymous]

I just picked up a low mileage ( 1,000 miles on it, so I'm told) '69 200 and plan to use most of the parts off my 170 for now, including the '68 distributor, larger volume fuel pump/filter assembly, and an early model small- bore 1100. I'll eventually look for a bigger carb to match the 1.75 intake opening, but plan to use this carb for now as it work's well.

When going to a bigger engine, do I increase jet size or decrease? My senses say go bigger, but I thought I recall somebody saying to go to bigger jets (and I did) when I put my motorcraft 2bbl on the 170. About how many sizes up or down should I start out with? I've been running a 64, and have several others to choose from including a 59 and 67, I believe. Thanks!

S-man

 

[MustangSix]

If the carb is working well now, leave jetting alone.

Carbs are just dumb mixers. They don't know what size engine they are on. They only react to pressure differentials. They will pass the same air/fuel ratio no matter if its used on a 170 or a 250, up to the capacity of the carb to handle the airflow.

 

[Anonymous]

Thanks!