Made a new Z friend only 45mi away in Pa. Had a very nice drive through beautiful Pa. and lunch. Spent the day talking carbs and geek stuff... a blast! Learned a lot.

Also planning research collaborations too. Stay tuned to this channel.

P.S. How many of you have ever seen this item that rarely sees the light of day except through a window?

Tony D you are not allowed to comment

Edited September 6, 201113 yr by Blue

Looks like the power valve?

Sir: Strike 1

Well, the name of the file is jet. Would you be so obvious?

I missed the fact the this forum does not convert file names to numbers... you hit it out of the park

Yup it is a flat top jet that is normally well secured deep inside a flat top SU. It only sees light through the fuel bowl window. My new Z friend showed me a great deal of flat-top details today including a cool tool he made to safely remove the jet,

Blue,

I see the score marks on the "nut part" of the jet holder...I had that too. They seem to be "glued" in and have to be forced out. The jet either gets clogged up with carbon (soak in Brasso does the trick), or the needle wears a slot in the jet holder. Did your new Z friend have any tips for removing the needle from the bottom of the piston? Some I have come across have been soo difficult to remove without bending the needle (as new needles are NLA as far as I am aware).

Good to see some in depth on the "boat anchor" flat tops

RIP260Z

Blue,

I see the score marks on the "nut part" of the jet holder...I had that too. They seem to be "glued" in and have to be forced out. The jet either gets clogged up with carbon (soak in Brasso does the trick), or the needle wears a slot in the jet holder. Did your new Z friend have any tips for removing the needle from the bottom of the piston? Some I have come across have been soo difficult to remove without bending the needle (as new needles are NLA as far as I am aware).

Good to see some in depth on the "boat anchor" flat tops

Thanks! my friend "Cptn Obvious" on this forum, is a superb investigator and data gatherer with great attention to detail. Plus "he has a lathe" (in joke). I know he addressed removing the jet by making a special tool, and also returning the jet to correct depth by another special tool but I do not know if he addressed the dreaded stuck needle. I would guess he would make a custom clamping tool like the one he made for removing the nozzle (in photo below) that grabbed the needle at the shoulder (in the groove). Some threaded holes in the clamp could be used to turn bolts that pulled the needle out in a similar fashion to the threaded holes in brake drums and pulleys that help removal. Heck a few holes in his jet clamp could turn it into a dual function tool!

Thanks for the Brasso tip.

Now I need to get me a set of flat tops to work in parallel with the Guru!

Did I mention that he has a lathe?

Edited September 6, 201113 yr by Blue

Phil, I don't have a pair to spare, but I do have a single flattop sitting on my garage floor, ready to give its life in the name of learning. If you want it, send me a PM.

Not too long ago, I checked my plugs and found they were fouled. Following my own advice, I read through the FSM and came across the diagram Phil posted. I was in a hurry and just did minor adjustments, using my ears as a crude tuning tool. I leaned out the carburetors a little and bumped up the fast idle to keep the engine at a nice idle speed. The end result was that the car behaved better, and the plugs didn't foul. To me, it was just as easy as working with the SUs.

I didn't think Tony was yanking our collective chains when he said there was something to the flat tops. I just hope I can open my mind up enough to understand.

Blue if you really want a set of flat tops, let me know... Guess what showed up just last weekend. Very low km's....

Hi Ian,

Love your car pics on another Z site I browsed earlier!

Blue,

Snip

Did your new Z friend have any tips for removing the needle from the bottom of the piston? Some I have come across have been soo difficult to remove without bending the needle (as new needles are NLA as far as I am aware).

Good to see some in depth on the "boat anchor" flat tops

I just checked and he used new rubber tubing and essentially put two pieces longitudinally along the length of the needle then clamped this in a vise (squeezing a hot dog). The rubber prevented damage yet it grabbed the needle. As well, the vise jaws grabbed the whole length of the needle thus distributing the force evenly and preventing any bending.

Edited September 7, 201113 yr by Blue

Hi Blue,

Thanks for the complement on my RS30. I have one pic in my garage below my avatar.

I like the tool and the way of removing stuck needles, will bear that in mind.

It is worth looking at/considering, the spindle the butterfly joins, it is like the SU carbs, they don't have a bearing and seal in from new, and the aluminium body and brass spindle gradually wear, leaving an area for air to be sucked in. So, it does not matter how good the carb is refurbished, if this is not done air is being drawn in that you can't control...you probably know this, but someone may not.

I like the idle circuit/idle mixture diagram, but for me (I have yet to try) is have it so each carb is individually adjustable. Especially if one carb is a little bit worn compared to its partner, each carb would require a different setting, and adjusting the one idle mixture screw is always going to be a compromise.

Keep up the good flat top work.

Cheers

Ian

Edited October 13, 201113 yr by RIP260Z