[Sunny]

EDIT: I've found another link that shows it might be a Mechanical Secondary Speed Demon. I found a 7 stamped under all the dirt which means it's either a 700 or 750 depending on the booster.. but I'm not sure the difference between annular and Downleg

I had this on my car before but it started leaking fuel. I want to buy a rebuild kit, but I have no idea what it is. Demon's website wasn't very helpful because the number isin't stamped on the rim.

It's stamped 169 on all four barrels on the bottom. One side has a P stamped. The other has an S, which I assume is Primary/Secondary

[cobalt327]

Unfortunately the links to all the pages and pdf's that used to make this easy are dead. I guess BG wants everyone to get frustrated and buy one of his new carbs. As if.

It is a mechanical secondary as you suspect, also called a double pumper. In Holley terms it would be a double pumper 4150 series. You can take a look here for more info, but if the BG site didn't help this might not either unless you were looking in the wrong place for the ID.

There should be a stamping on the rim of the airhorn (I don't see anything on yours) or an etched ID number somewhere on the carb.

In any event, you have the downleg booster (see below). Makes it a 750.

Annular boosters:


Downleg boosters:


Straight leg left, annular right (both upside down):


Hope this helps.

[gearheadslife]

Originally Posted by cobalt327

Unfortunately the links to all the pages and pdf's that used to make this easy are dead. I guess BG wants everyone to get frustrated and buy one of his new carbs. As if.

It is a mechanical secondary as you suspect, also called a double pumper. In Holley terms it would be a double pumper 4150 series. You can take a look here for more info, but if the BG site didn't help this might not either unless you were looking in the wrong place for the ID.

There should be a stamping on the rim of the airhorn (I don't see anything on yours) or an etched ID number somewhere on the carb.

In any event, you have the downleg booster (see below). Makes it a 750.

Annular boosters:


Downleg boosters:


Straight leg left, annular right (both upside down):


Hope this helps.

I think to get info now you have to go to the parent company that owns them now.. holley