73 F motor CARB jetting question

[cruiserbrett]

Trying to make sense out of a used carb I bought and am going to make work for the time being to send my 73 FJ55 original carb off to Jim C for a rebuild. Truck is at sea level, stock F engine.

Someone, at one point put a carb kit in it, but the jets were not legible, scraped with screwdrivers, etc. and the 180 jet was in the primary side and the 120 in the secondary side. power valve jet had no number legible, etc. So to get a good baseline:

So, this is what I have so far:

Main Jet: 120

Secondary Jet: 180

Power valve: 60, but I have a 55 and a 90 as well.

Now my question is this: there are the two long idle correction jets. No legible numbers on these. One is longer than the other, and they have two different sized holes. Is it safe to assume that the larger hole one goes on the secondary side since the manifold vaccum would be lesser, and this would allow more air emulsion?

Large hole air correction jet: Secondary????

Small hole air correction jet: Primary?????


Anyone with some insight? I did rear the 73/74 thing in the tech, but some of my jet numbers dont match, so I am trying to figure out what will work.

If there are some tuning changes, let me know...

 

[peterb]

Brett
You may know this but SOR has a page on jets. If you get the date off the top of the carb you might be able to figure out what jets the carb should have.
Can't help you with the slow/correction jet info. Will the long one fit in both holes?
At Jim C's recommendation, I recently got a kit for an F carb from Kurt at Cruiser Outfitters. It came with the slow jets, regular jets, including the power valve jet and the high altitude jets.
Good luck
Peter

 

[Degnol]

I just went out and pulled the air horn off an April '73 carb and checked the emulsion jets? (the long skinny ones) and they are equal length and both marked "50". HTH


Ed

 

[cruiserbrett]

I just went out and pulled the air horn off an April '73 carb and checked the emulsion jets? (the long skinny ones) and they are equal length and both marked "50". HTH


Ed

Ugh. Now I have to find another 50...(assuming I have a 50 and an 80-per the 73/74 carb tech writeup)

 

[Degnol]

Ugh. Now I have to find another 50...(assuming I have a 50 and an 80-per the 73/74 carb tech writeup)

You can have mine, if you want(free, of course). Did they have Federal/Cali carbs in '73? That may be the difference?

And I think my main primary is 1.14

Ed