Zedyone_kenobi

Just wanted to thank all of you again for the help. I am usually pretty savy with carbs. Was a bit of a Holley guru in my V8 days. and these SU's seem just wonderfully simple, but often the most complex things are the simplest. For the life of me, though, everything I do seems to result in ziltch. They are so clean you could eat off of them. This is truly a strange case. After I get the wideband stuff, it will at least point me in a direction...lean or rich.. well lets hope so.

It seems I am right with the first two methods Blue. Nothing is really far from being 'spot on'. Everything appears to be as it should. I am going to blow out all the fuel lines and put everything back together. Then I will get some clear tubing and try to mark where the float comes up on the car. But all of this is just for ****s and giggles until I get my wideband installed this week! Should be here tomorrow or wednesday.

Screw it I am getting Mikunis! HAHAAH

checked the floats this morning...They are right at exactly .55" when they first contact the seats +\- 0.010" They pass the blow test as well, and shut off fuel right about the same time too. Humm, another lead down the tubes. I did notice that when I first looked at the front float, that the wrist pin was dislodged on one side. Now I do not know if I did that when I removed it or not, but it was the only thing noteworthy at all in inspecting the floats. If there are no more ideas, I will put them back on the car? What torque goes on that 10 in lbs? It is not much?

Okay, I will make these adjustments today. I understand what is going on now I think... The Z therapy video has the float hung upside down and it is about .55" and level with the float top.. that may be due to the Gross jet he is using, which seems to have FAR less travel than my needle and seat. More on this later today...

Well how thick is that float gage?

I think that float was just stained

Yup the bowls looked very clean at first glance, I need to remove the fuel lines to ensure they are clean

Unfortunately I drained them prior to removing the bowls! DOH!

NOTE: I may need to find out when the needle and seat actually shuts off the fuel to know how right or wrong this actually is!

Here are my floats as they came out of my carbs Front float: Back Float: Okay, not if I am not mistaken, the SU video says I need .55" of clearance between the level lid cover and the bottom of the float... Does this sound right. I have about .190 no the front and .210 on the rear. The pictures I am looking at shows the float hanging almost level when adjusted properly. If it is that off, then it would explain why no minor tweak of my mixture ratio nut would make a bit of difference. Now if this is normal, I may have to do one of those clear hose tricks you guys have mentioned. Is there a preferred way to check float level. I am about to do a search to get educated. My factory service manual says that dimension 'H' should be about .55" but it does now show where dimension H is on the picture! This may be a key piece of the puzzle!

Okay folks, I decided to try to swap out my SM needles for some OEM needles from Z Therapy. I got the mixture at 2.5 turns, which is close and it is actually doing a similar thing as before, maybe worse, but it is close. I was still able to pull to red line if I floor it in second, but anything part throttle just pops up a storm out of the exhaust. I am going to pull the float bowls this afternoon after the car cools down.

nope, I forgot about that, but I have tried that before. Funny though, I have no idea if it helped or not.. I do not remember.

Well went for a test drive, and it is still popping through the exhaust. I will recheck everything balance wise, and mixture wise in the morning. I will also probably change needles, even though I do not think it will make a bit of difference.

about 2 seconds is what it takes to push them up. What I did find that both my screw valves that act like a damper in the SU oil are both exactly .348" plus or minus many half a ten thousanth. Very close to each other. I took off the first carb dome today and cleaned the begezzus out of it. I used some gun cleaning towlettes and a good thin plastic pushrod. I cleaned every where there is metal to metal in close proximity. It went together and the piston acts like a mirror at all times to the rear carb piston with the exception of one thing. WHen I push the piston ALL the way up, it took the front piston a good 4 or 5 mississippi's to come down.. while the back one dropped right away. In an any other position, the pistons dropped identically, but all the way up, the front SERIOUSLY lagged the back. This may explain why my car only stuttered, at high rpm, at part throttle, and while changing throttle positions. At wide open throttle it would just go open and not have to adjust... So long story short, I took everything apart again and cleaned it up including the oil that was from the overfilled front SU oil reservoir and whala, the pistons fall at the same rate even from the very top of the stroke. I got my stock SU needles in but have not touched them yet. Only going to change ONE Thing at a time. I have high hopes that this may have fixed things. Perhaps my tolerances on my piston and dome are such that any liquid contamination at all was making it hang up. This is going to be interesting. If this does not work, I will let you guys know, and then get that O2 sensor installed ASAP. I will also try the NO SU oil trick and see how it acts.

Great advice! Thanks Captain! Just so you know my SU's are very hard to push up and they do leave a noticeable dent in your finger. Check valve okay. My standard needles have arrived, but I am going to try to clean the damper and dome more thoroughly today. That really seemed to help out yesterday. It was Steve91tt idea, and I think it paid off. I ordered an innovative O2 wideband yesterday as well. I will get that welded in and the guess work will be over when it comes to what is happening with my carbs.

Just want to thank steve91tt for coming to the house today to give me a hand. Just to update the thread. Steve took the dizzy with his pertronix out and we put it in my car and ran it with the same problem surfacing. Then we checked a different coil and it still happened. However, steve then suggested that we take a look at the pistons and the SU domes for cleanliness. Well they had some varnishing on them but nothing too serious. I cleaned them off and reinstalled them (first time the domes have ever been removed since I bought them from Z therapy). The car ran better with no popping until about 5500 rpm. Very clean running We also think we have the problem narrowed down to something in the domes, as the car will hold an rpm with little fuss, but the second I change the pedal position, it starts to sputter and pop out of the exhaust. Since I am VERY confident now that I was wrong thinking it was a timing issue, I am convinced it is a carburetor issue. Which means the time has come to increase the amount of data we have to work with. I will place an order for a real time wide band O2 sensor and we can further diagnose this issue. The O2 sensor will come to be more useful WHEN I get my triples one day, so it is money well spent.

Great work!!! keep up the momentum! I think you have a real fun project on your hands. Enjoy the drive man!

I checked my fuel lines and they are peachy. They are supple and are holding their shape well. I have not touched my float levels. I have ordered a standard OEM set of SU needles AND a set of float bowl gaskets from Z therapy so when I tackle the float levels I will be ready. copy that on the timing chain. I forgot my mechanics there. One more reason to check to see if the valves are adjusted correctly AND if the timing chain has any stretch. Can fix both at the same time. By the way, while I am thinking of it. I would think you should check for timing chain stretch while the engine is hot. But I have not checked. Is that the case.

MY car has 71k original miles on it. Since I am thinking that my issue lies not in my carbs but in my timing somehow,I was wondering if my timing chain may have some stretch in it, which is not allowing me to time it right. But I am not sure if that would make me run advanced or retarded. I will have to think about it. Nevertheless, I need to pull my valve cover and check to see where the heck I am when it comes to timing AND valve lash.

Merry Christmas guys, and happy new year. My God bless each and every one of you with health and happiness in 2012

I will check for you, but remember I had it recurved, cleaned and had new bushings/bearings installed. , so it is nothing like stock any more. Still I wish I had an extra dizzy just to see what a stock one would run like. I need another data point. Just for kicks I installed a brand new in the box set of NGK plug wires and a new cap. Still does the same thing. These plug wires have a 5 kOhm reading, were as my taylor wires had a 0.740 kOhm reading. Car ran exactly the same. Last thing I did was advance my timing to 17 degrees static and I will see how that runs tomorrow. I have yet to hear any pinging so I will do that. If that fails I will order a new valve cover gasket and take a look at my cam shaft. It is possible that I may have a worn lobe, but I honestly think that is highly unlikely.

tomorrow morning first thing I am going to do a compression test... I did one 3 years ago, but we have to check it off the list.

yes, brand new cap and rotor. Well less than 4 month old and 400 miles. I advanced my timing to 17 degrees static now which should yield me about 36 degrees total advance. Which I think is plenty. I did order new float bowl gaskets today and some OEM factory needles. We will see how they act if I need them. Today I experimented with my mixture. It still pops profusely at part throttle, Here is an interesting tidbit. As long as the rpm is increasing it seems to barely notice anything, but when I slowly creep up on about 4000 rpm, it spits and sputters if I hold it there. How about some SU help here. During acceleration the pistons rise, but when I reach the tail off of the acceleration, I would think the bowls would drop. Could my bowls be dropping way to fast, causing lean spot? OH I run standard issue SU oil that MSA sells. No idea what weight it might be. It came in a clear bottle called 'SU oil'

wow, less than one turn! My car would not even run like that... amazing how different two mostly stock cars are..