Mmm Carbs...

[MrFancypants]

Ok so I finally brought my 260Z home and started cleaning/rebuilding the intake side of things. All the plugs were totally fouled so things are way out of whack. I had no experience with carburators before this, so it was quite the learning experience. Most of it makes sense after a little online research and getting your feet wet taking it all apart.

 

First, the good news. Whoever had this car before installed a header and the intake off an earlier 240Z. Round tops baby, yeah!

 

I cleaned and rebuilt the carbs, cut new gaskets, checked for damage and made sure everything moves smoothly and without binding. Ztherapy.com was down all last week so I had to wing most of it. Thankfully it's up now and it looks like everything I guessed on was correct. Things went well and nothing broke Here are my questions:

 

1. I had to use some new 3/16" fuel hose between the float bowls and the bodies. Ztherapy says this is a no-no. Anyone think otherwise? At $8 per hose it seems a little steep. They also say the stock hoses contain silicone, but I thought silicone hoses werent suitable for fuel.

 

2. The pistons move smooth and easy up and down before I add oil and install the dampers. After adding oil, one piston takes significantly more pressure to lift than the other. Is that a problem? They both move smoothly and with more pressure than no oil/damper and lower at the same speed, but the rear carb is easier to push up.

 

3. Do I really need a Unisyn to match these things or can I get it "close enough"?

 

4. I read on here somewhere that the starting point is -1.5 turns on the jets, but Ztherapy says -2.5 turns. Who's right?

 

5. There is a lock nut that seems to hold down the jet adjuster. Do I just tighten it down after adjusting the jet and all is good?

 

6. Im fuzzy on how a sight glass works on the float bowls... or if it's really necessary. Anyone care to explain?

 

7. Is it worth removing the carbs again so I can remove the balance tube for cleaning? Does it get gummed up inside?

 

 

I dont have a VCR, so dont suggest getting the Ztherapy video, please

 

 

 

- Greg -

[MatMan]

1) Yes, bite the bullet and get the ZT hoses. These lines are pliable compared to regular fuel hose, and will let the nozzle seat all the way up like they are supposed to, while the thicker hose will actually make the nozzle stick open (way rich).

 

2) IIRC, as long as the pistons drop at the same rate, everything will be ok.

 

3) It is safe to say that the minor investment in a vacuum unisync is a wise investment when you have carbs.

 

4) 2 1/2 turns down from full up is correct for a "starting point."

 

5-6) Not sure. The ZT video explains all the minor details with great clarity, although it is as boring and mind numbing as a catholic wedding. (VCRs are really cheap at the local Salvation Army/Goodwill)

 

7) I haven't had an experience of the balance tube gummed up.

 

You may wish to visit an other Z site (CZC) for more info. on stock carb specs.

[WEBEZEEed]

Take a piece of the fuel hose to N.A.P.A. they mathced mine up for 30 something cents a foot still pliable and right o.d. so the stock clamps still fit, 2 1/2 turns is a good starting point.