Gas Depth in Float bowl, when excluding float volume

[Gary in NJ]

I think its time for a compression check.

[hogie]

Already done with a crappy, non accurate Autozone rental. It was consistent across the board at 100. Which I know is low, but the meter was reading way low compared to a known air source i.e. my compressor. From what I remember it was reading around 70 when I was blasting 120 into it (with no leaking)

So yeah, I dont know the exact compression, but that it at least is close from cylinder to cylinder.

[Gary in NJ]

The reason I asked about the compression check is it sounds like you've hit the usual suspects on the carbs.

A fuel pressure check might be helpful. You may have low pressure at low rpms and the rear carb is the only carb to receive fuel. As rpms increase the fuel pump can deliver enough pressure.

You mentioned that you can remove the first 3 plug wires with no effect below 1500 rpm. Have you checked for spark? I assume you have spark if you were able to run a timing light off #1.

Fuel, air, compression & spark. A problem with any one and you have a non-runner. The question is which don't you have below 1500 rpm.

Check that fuel pressure.

[Arne]

I did not read thoroughly every post here, as I don't have time to get too tied up while here at work. But in a quick scan I did not see any reference to checking for vacuum leaks at the throttle shafts. If the shaft bushings are bad, trying to get it running right at idle can be nigh impossible.

[hogie]

The throttle shafts seem to be fine and i am getting spark on all cylinders. Both as tested by timing light and getting the plug wires to arc.

I've got baby duty tonight so i wont get a chance to do anything else tonight. Tommorow i will try to pull the carbs and flip sides on them and see if the symptoms do too. After that another good soaking and new rear gaskets. I also picked up some nice honda fuel line to avoid future fires.

[Gary in NJ]

Can we get some close up photos of the carbs? I'd like to see the underside, the linkage and any other views you could provide.

[Arne]

The throttle shafts seem to be fine...

I'd test them for leaks. With the engine idling, spray a little WD40 (or your favorite substitute) at the shaft pivot points, on both sides of both carbs. If the idle changes (either up or down) during this process, the shafts are leaking unmetered air and you will never get them adjusted correctly.

[Travel'n Man]

Congratulations to the most extreme event of your life!! The highest high you will ever have - my son is 24 and I am still in awe of the total experience! What a God given high.........amazing and woderful!! Be ready for a great adventure for the rest of your life - it only gets better!

A few questions:

How are you measuring your air flow? What tool are you using? I use a:

http://www.cbperformance.com/catalog.asp?ProductID=572

Is there any blockage of your nozzles? (Have you removed them and looked)?

Have you put some grease on your nozzle bodies?

Is your choke moving correctly ?

Are your pistons moving freely or are they sticking at all?

What floats are you using? - in part of your thread you stated that you could put the originals back in??

Are you getting flow out of the fuel lines going into both carbs?

If you had only one carb working you would be running off of 3 cylinders and running extreemly rough - are you running smooth when running?

I am running a L28 with duel Hatachi's and an E88 intake with points:

I just set my float bowls last month and the front at 9/16" and the rear at 1/2" (both on the heavy side of the line) - after a little adjusting of my idle adjusting nut I am pretty good now - a little phat but not too crazy. I think most of the Z's run a little phat anyway

I used a cardboard cutout measured and set the lid upside down and insert the cardboard cutout to sizing (I also replaced the seat and needle valves). You may need to make sure your seat and needle valves are working correctly and not blocking your gas flow from the float bowl

Again - you may want to verify fuel to the float bowl and out of the float bowl of each float bowl

Why are you using Honda fuel line for your carb line? Is it the correct sizing and diameter?

A lot of questions but all of us will need a little more info. On your responce you will need to address the front and rear carb independantly so we can see what is happening to each carb.

[hogie]

Just got done with a feeding/changing session and it is definately an extreme change....good so far, but very tiring.

Travel'n that is a ton of questions, but here is what I have for answers

The nozzles seem to flow clear to me, I have shot a bunch of cleaner through them and

Wd40'd up the sliding section. Though I hadnt heard to grease it, I will try that.

The Choke actuates good, though on return with my old lines I have to manually move up the rear on occasion. Most of the time it moves all the way up.

The pistons move extremely smooth, though with the 20wt oil and new seals they are stiffer than when I bought the car and whatever fluid it previously contained. They clunk when they hit bottom. The centering nubs are still on the back carb, but not on the front.

I have the plastic floats. I mentioned returning to the factory float valves. I am currently running the factory front float valve and the GP Sorenson Rebuild kit rear float valve. Set to 14.28 mm front and 12 mm rear. I ground down a bolt to the proper length and set the valve to close at the point of contact. THis is with me blowing air through the lines and the float held right side up. I am just a little high on the back right now...closer to 25 than 22mm in the sight tube.

The car generally idles pretty smooth as is, even if the rear cylinders are doing most of the work. It only gets crappy when I lift the rear piston all the way up. And even then it doesn't die if it is warmed up.

There is fuel coming out of each line and close to the height of the nozzle.

I picked up the honda fuel line as motorcycle shops were mentioned as a source and this stuff is supposed to be non-hardening. Also, it was cheap and as close to home as autozone. The inner diameter is really close to the replacement lines in the rebuild kit. Just a bit over in fact.

I think I have hit everything there is so far. I don't have any way to check my fuel pressure just yet, but that can be changed shortly. I have a low pressure electric fuel pump I may plumb in temporarily to see if that eases any of the problems. I think it maxes out at 5 psi.

Here are the requested pics and a baby for good measure

Thanks for your help

Edited May 12, 2010 by hogie

[Gary in NJ]

A picture is worth a 1,000 words. OK, a few things here.

First and foremost, cute baby.

Second. The hose from the float bowl to the nozzle is incorrect. It's also pinched on the front carb (4th picture) and that will restrict flow. There is a thin-walled, pre-shaped hose that goes there. It is available from ZT.

Third. The "hanging nozzle" is a problem. It could indicate a) the need for grease on the nozzle, or a poor needle/nozzle fit. Use a liberal about of white grease on the nozzle and reinstall it (without the hose attached and choke arm attached). Work it up and down and ensure that it moves freely. Hold it in the up position and ensure that the piston is moving freely. Once you know that you have a good fit, attached the choke arm and run through the movement again. Then attach the fuel hose and do a final run-through.

Lastly, What kind of headers are those and do you like them? I'm looking for headers myself, especially ones coated like yours.

This is a lot of work, but a lot more fun then an extreme diaper change

[hogie]

They came with the car so I am not positive on this, but I think they are from MSA. Almost all of the receipts came from them, though I couldnt find the one with the header listed. They had a sticker marked made in mexico, but that has burnt off sometime in the last few months. It mounted up to the MSA premium exhaust without much fuss and sounds really good to me. Though, I really haven't gotten to drive it with everything working right.

I will change out the fuel line and grease everything up real good tonight. Hopefully that will prevent me from doing the full tear down.

You are right about the diaper changes though. I have no clue how he can completely fill a diaper the second you change him. That and pee on the wall and myself again two minutes later.

[Gary in NJ]

You need to learn the "cover the penis" procedure. If you're not actively wiping something, let the open diaper flap over the 'lil fire hose.