Need for vacuum retard?

[fj40nc]

It's a de-smogged 11/74' fj40 that I've got with original F 1.5 motor and factory carb. While reading through every thread that I could, trying to find the proper vacuum setup, I've come to a dead end. Questions being...

Can I just cap all vacuum lines?

Or

Do I need at least one from dizzy to intake?

Or

Do I need just one from base of carb to diaphragm at top of carb?

Or

Questions 2 and 3 in combination?

 

[Fast Eddy]

If you have a retard dizzy, you should cap all the lines and rely on mechanical advance.

Ideally, you would find an advance dizzy and get your carb ported. Check out the @Trollhole products. Not sure if that carb is ported or not. Maybe he'll chime in.

 

[pedwards]

I have the same F155 in my '69. stock carb, stock dizzy.
Everything is capped and it runs well.

I've experimented by hooking up the vacuum advance on the dizzy to various vacuum sources ( carb, air intake) and i dont have any noticeable difference. I might get some better mileage, but i dont notice any more HP.

My advice to you would be to cap everything, and if you really want to play with your vaccum lines, get the proper VSV hardware.

best of luck.

 

[Howard705]

Vac advance is for more fuel mileage under lighter loads.

 

[fj40nc]

I appreciate the feedback, always loved the forum, just now starting to post.

 

[skidplate]

I have a '75 2F with a vac pot that has both an advance and a retard connection. The retard side has been bad for years and I've tried hooking up the hose to both sides and I can't tell any difference in performance. I finally just capped off vac line from carb with nothing attached to the dizzy. The truck runs great with excellent throttle response. Just recently I pulled the dizzy to clean and inspect and make sure the mech. advance was clean and working. My .02

 

[Fast Eddy]

I have a '75 2F with a vac pot that has both an advance and a retard connection. The retard side has been bad for years and I've tried hooking up the hose to both sides and I can't tell any difference in performance. I finally just capped off vac line from carb with nothing attached to the dizzy. The truck runs great with excellent throttle response. Just recently I pulled the dizzy to clean and inspect and make sure the mech. advance was clean and working. My .02

It's not advance and retard. It's advance, and advance more.

 

[Downey]

Dear Mr. Eddy, how can that be with a hose on each side of the diaphragm, must pull into opposite directions- - - what am I missing?????

 

[skidplate]

For clarity this is a pic of my dist. FSM says back connection is for retard and the front for advance. If i put vac. on the back it won't hold it, but will advance if vac is applied to the front. Makes no difference in performance.( Pic is for another thread about timing.)