Zaspen

3.5 turns is the highest idle. I tried 4 turns but had the same issue. I will check the floats tonight.

I believe the description of the piston rising too quickly and then becoming to lean was spot on. I made a big time rookie mistake and assumed the dashpot oil level was correct and it was low. I never looked into the correct level and since oil was touching the bottom of the "dipstick" I thought all was well. I put in the correct amount and the chatter is gone! But now without the chatter when I take off its like a bucking bronco. It's as if I'm just learning to drive a manual. If I give it gas after the clutch is out it starts bucking. Not like a loss of power I don't think but I'm not sure. It does it as I shift in 2nd also. Any thoughts? Thanks to all for the help with this!

I need to do a plug check soon. I think I'll take it to work tomorrow and try on the way home.

So I believe Z Therapy uses ATF in the dashpots so that is what is in there. I attached a video that shows the 'chatter". Perhaps its more of a hesitation. The first time I rev in the video is from idle and it happens, the second rev I don't let it get down to idle completely and it seems fine and then the third is again from idle and it hesitates again. I feel this hesitation when I take off from a stop or in between "slow" shifts. I also tried the lifting the pistons again and it dies with any amount of lift <1/32" 20190521_174657.mp4

I'm using the stock manual pump. Not sure what you (siteunseen) mean about getting the cables right. Are you referring to setting the choke cables correctly? I basically pushed the choke lever fully open and attached the choke cables with the cable levers fully dis-engaged. I then made sure they opened the butterflies evenly and pushed the jets down. Is there more to it then this? I'll give it a shot with the updated timing and see what happens also. I do think at 2.5 turns out the car would be very lean- bet I will confirm.

If I back the timing of to 7 BTDC the idle drops a little bit. It also increases a little bit if I advance it. Not nearly as much as I remember with the Holly carb. If it raise the piston with the pin the idle drops way down an almost stalls the car. Both carbs have the same response. I though this indicated a lean condition so I lowered the jet in 0.5 turn steps but the response to the piston lift never changed. I have the jets set at 3.5 turns out normally and took them all the way down to 5 turns and there was very little change to the piston lift results. At 5 turns out the car would barely idle under normal (no piston lift) conditions.

I set the timing at ten and it advances to about 35. Idle is around 750.

I just put a set of Z therapy SUs on my 72 240 after removing the Holley 4 barrel it came with and I'm having an issue with a slight stumble off of idle. I have them balanced well and the valves and timing are good. I have the mixture set to the highest idle as well. I am running water in the carbs/manifold and the problem is bad at cold and still noticeable when warm. As I rev the engine it stumbles a bit and the pistons in the carbs seem to chatter a bit when they are rising as the stumble happens. If I richen the mixture the problem seems to get better but the idle drops way low. I can't tell if the problem is actually better at this point or if its just so rich that it slow to rev and I can't see the stumble. I tried using a Gunson color tune but I'll be damned if I can tell the difference between yellow/blue and white/blue. Any words of advice related to my problem would be greatly appreciated!

I'm just looing for the bracket. I have the check valve/rubber

Thanks- I didn't know about that site. Any clue when if the black ones will be available again? I'm guessing you are in the know since you have the web address in your signature.

That was a thought I had but the needle bearings are a little longer and are chrome (or rust) finish not the black oxide. Everything is back together and working so its all good. Thanks!

I'm trying to find the metal clamp that holds the master vac check valve to the firewall. Does anybody have one they would sell? Thanks!

Beer.... The cause of, and solution to all of life's problems.

I often stare at the ceiling as I lie awake and think of all the money I throw at the car!

Its not the roll pin from the bottom of the distributor. Thanks for everyone's input. I'm feeling pretty confident its not from the motor. I'll take my dime and leave!

Its a 72 240Z. Its solid metal and sticks to a magnet. It appears to have a black oxide finish with some wear down to the base metal. It isn't a roll pin or a plastic rivet. Picture attached at a different angle. I saw nothing on any of the parts diagrams that this could be but like I said it just appeared on my workbench. Thanks!

I have my engine apart to replace the head gasket and timing cover gasket and I noticed today a small pin on the bench. I'm not positive it is from the engine but I have never seen it before. On the bench I have had the oil pump, head, timing cover, thermostat housing and the chain tensioner. It doesn't appear to have an oily film on it but It could have been cleaned while I have been cleaning parts and scraping gaskets. It has a black coating on it and has one small area that shows wear. Any thoughts?

Thanks for a the info. Great idea to make sure the splines are all clean before reinstalling.

Side to side. I took a better measurement and its really about 0.030". I think I feel better about it now. thanks!

Side to side. A better measuremet has it at about 0.030"

I have yet another question for the gurus in this forum. I pulled my transmission to replace all seals/orings and found what seems to be "a lot" of play in the input shaft. My semi-accurate measurement technique shows around 0.045" of play back and forth. Is this normal. None of the manuals I have give any sort of measurement on this. The car has 125K miles on it. Thanks!

Thanks for the info on that thermostat alternative maybe I will just try that with some SS tubing.

I've seen both views on the heaters. With the thermostat I'm hoping they just warm up then don't get too hot.

OK- thanks again for looking!

Cool- thanks for taking a look!