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Can anyone tell me what the part is called. I’ve recently discovered that this thing is the reason my rx7 won’t start/ stay running. Can anyone tell me what it’s called and best place to get a replacement.
That's the vacuum pot for the secondaies on your carb. You need that, unless you're stripping the carb down and converting to mechanical opening only. It looks to be in pretty good condition, other than being apart.
Where it bolts to the carb there are 3 bolt holes and a vacuum port (the little black tit). Did you block off that port on the carb, or are you saying it now runs better with that vacuum leak??
If you didn't block the hole, then I think the vacuum leak created is leaning the mix (on the secondary side) to a better ratio. That would mean gas was coming through the secondaries when it shouldn't, or too much or something along that line.
If you removed the Vacuum pot and blocked the hole, and now it seems to start and run better, then yes there was something wrong with the pot. Leaking gasket, gasket, stuck open or closed, something.
Either way, your secondaries will not function without it unless you modify the carb for mechanical secondary operation. There are plenty of write-ups on how to do that. But on a street car you may have to adjust your pedal foot technique slightly.
Where it bolts to the carb there are 3 bolt holes and a vacuum port (the little black tit). Did you block off that port on the carb, or are you saying it now runs better with that vacuum leak??
If you didn't block the hole, then I think the vacuum leak created is leaning the mix (on the secondary side) to a better ratio. That would mean gas was coming through the secondaries when it shouldn't, or too much or something along that line.
If you removed the Vacuum pot and blocked the hole, and now it seems to start and run better, then yes there was something wrong with the pot. Leaking gasket, gasket, stuck open or closed, something.
Either way, your secondaries will not function without it unless you modify the carb for mechanical secondary operation. There are plenty of write-ups on how to do that. But on a street car you may have to adjust your pedal foot technique slightly.
all ik as of rn is that if we pull it it allows the car to idle and start up. i had my undle pull it one time while i fired it up and he could control the idle by pulling it or pushing it in. and no theres nothing blocked off. everything that needs to with the emissions delete is blocked off
all ik as of rn is that if we pull it it allows the car to idle and start up. i had my undle pull it one time while i fired it up and he could control the idle by pulling it or pushing it in. and no theres nothing blocked off. everything that needs to with the emissions delete is blocked off
Got it. So if you manually operate the secondaries instead of letting vacuum open it, you can get it to start and run. So it can't stay lit on the primaries alone - there's a problem with the primaries' floats, jets or idle circuit. The motor needs to run on the primaries, well... primarily. Is your uncle going to sit under the hood to pull that little rod every time you want to drive the car? Doubtful.
So even though you can artificially get the car running on the secondaries, you can't drive around like that. Carb needs a full cleanout and rebuild, or primary linkage corrected if it's out of wack.
Where are our rotary mechanics? GSL-SEforme? Bueler? Bueler?
You rang? I would start with a full disassemble and thorough cleaning of carb,assembled with fresh gaskets. Try to reuse original needles/seats.
Before taking anything apart,while engine can still be started,look closely at fuel levels in primary/secondary float bowl windows. May need a mirror to look at rear bowl/window level. Both should be at 1/2 full in window and must be when reinstalled. If they are,don’t do any “adjusting”. Thorough cleaning of all passageways of fuel/air circuits,jets,air bleeds will restore full function of carb. Don’t change anything,”lightly” turn idle mixture screw clockwise til it bottoms- no force needed here- and count and record how many turns it takes to lightly bottom. You need to remove this to clean passageway behind it and return mixture screw adjustment to what you recorded,this will allow car to start and run and warm up and final adjustments to mixture/idle speed can be done after checking/setting ignition timing which should be done at this time.
Leave idle speed screw where it is,no need to remove and will also allow car to idle while warming up. Final idle speed adjustment is done last.
You rang? I would start with a full disassemble and thorough cleaning of carb,assembled with fresh gaskets. Try to reuse original needles/seats.
Before taking anything apart,while engine can still be started,look closely at fuel levels in primary/secondary float bowl windows. May need a mirror to look at rear bowl/window level. Both should be at 1/2 full in window and must be when reinstalled. If they are,don’t do any “adjusting”. Thorough cleaning of all passageways of fuel/air circuits,jets,air bleeds will restore full function of carb. Don’t change anything,”lightly” turn idle mixture screw clockwise til it bottoms- no force needed here- and count and record how many turns it takes to lightly bottom. You need to remove this to clean passageway behind it and return mixture screw adjustment to what you recorded,this will allow car to start and run and warm up and final adjustments to mixture/idle speed can be done after checking/setting ignition timing which should be done at this time.
Leave idle speed screw where it is,no need to remove and will also allow car to idle while warming up. Final idle speed adjustment is done last.
The carb has already had a rebuild and has been cleaned already before I bought it. We’ve messed with the mixture screw before and it did nothing. But I’m also wondering if this is my issue. So when I first go the car me and my buddies worked on it and he noticed that on the primaries opened(not running) so we tied the primaries to the secondaries and no me they open at the same time. Now doing a little more research I’ve discovered the secondaries don’t open till the cars running and driving. So at this point I’m considering the mechanical secondary conversion. If I were to take off the actuator would this solve my issue or is there something different I should try??
1st,having a hard time following your grammar.2nd,other than what you were told by the seller,do you KNOW the carburetor was rebuilt(professionally) and what was the reason for the rebuild? Has this car run since you've owned it and have you driven it and how much?
Something doesn't add up,if the car you just bought won't run,shouldn't you be talking to the person that sold you the car-or did you buy it as is? I put very little credence in what a seller tells me-until i can prove it myself.
So,you and your buddy worked on it and found the idle mixture screw did nothing,are either of you mechanics? I ask this because of removing the part(secondary actuator diaphragm) that allows the car to run does not make any sense,other than allowing you to manipulate secondary linkage to allow air and fuel in for the engine to run-this is indicating the primary side of carb,including the idle circuit is doing nothing. Anytime adjusting the idle mixture screw makes no difference in how the car runs? would indicate a problem internal to the carburetor or a sizeable vacuum leak which brings us back to you needing to be clear about what you're saying.
To answer your question, mechanical secondary conversion is not the answer to your problem,nor is taking off the secondary actuator. The original REAL problem must be identified and repaired,taking parts off a carburetor is never a fix or the route to take.
We can assist you in determining how to go about diagnosing what the underlying problem is but without specific information from you,we can't help you. Start by answering the questions i have asked you as clearly as possible to allow us to point you in a direction to take. Reread my last post regarding float levels and include that in your response.
1st,having a hard time following your grammar.2nd,other than what you were told by the seller,do you KNOW the carburetor was rebuilt(professionally) and what was the reason for the rebuild? Has this car run since you've owned it and have you driven it and how much?
Something doesn't add up,if the car you just bought won't run,shouldn't you be talking to the person that sold you the car-or did you buy it as is? I put very little credence in what a seller tells me-until i can prove it myself.
So,you and your buddy worked on it and found the idle mixture screw did nothing,are either of you mechanics? I ask this because of removing the part(secondary actuator diaphragm) that allows the car to run does not make any sense,other than allowing you to manipulate secondary linkage to allow air and fuel in for the engine to run-this is indicating the primary side of carb,including the idle circuit is doing nothing. Anytime adjusting the idle mixture screw makes no difference in how the car runs? would indicate a problem internal to the carburetor or a sizeable vacuum leak which brings us back to you needing to be clear about what you're saying.
To answer your question, mechanical secondary conversion is not the answer to your problem,nor is taking off the secondary actuator. The original REAL problem must be identified and repaired,taking parts off a carburetor is never a fix or the route to take.
We can assist you in determining how to go about diagnosing what the underlying problem is but without specific information from you,we can't help you. Start by answering the questions i have asked you as clearly as possible to allow us to point you in a direction to take. Reread my last post regarding float levels and include that in your response.
Ok I hear you. So here’s the gist the car had three owners before me. It ran for the first two but before the third guy bought it it sat for a few months. After that is when it stopped running well/not at all. So when the third guy bought it he rebuilt the carb( not professional) and set everything back to how it was when he took it apart. In the process of that he also did the emissions delete. From what I can see and tested all ports that need blocked off are. We ran into one issue of the fuel pump not running so we did a bypass so it starts when you turn the key. Fuel filter was cleaned but was replaced by the third guy when he bought it. I was also concerned about the apex wear. Checked that and compression is great and it’s mileage on it as of right now is 76,000. We then decided to take apart the carb but just took the top part off so we could see the bowls jets etc. jets are clean It’s getting fuel to the bowls floats are working everything seems good there. That was also when we tied the primaries and secondaries together. Now we did have it start before we took the actuator off but it was choppy and the way I was told is it sounded ported but it’s not. The rotors sounded out of sync. So we thought timing issue so I reset the timing on the dizzy (lining the dimple with the notch). Put that back in and nothing. So we decided starter fluid to help spark it to life. That worked but ran for 5 seconds then died like it had no fuel and my foot was to the floor trying to save it. So then we thought ok fuel issue. We didn’t mess with that. So my uncle who was there when I bought it remembered that the third guy said that the diaphragm in the actuator needs replaced. So my uncle decided to take it off and mess with it a little and asked me to try to fire it up while he pulls it. So we put some fuel in the chambers pulled the choke and he pulled the actuator and fired right up. This time rotors sound in sync smooth firing idled perfect at 500rmp everything sounds good. Now he also discovered he can control the revs by pulling it or pushing it in. So we came to the conclusion that that maybe be our issue. But now you guys are saying that shouldn’t be as to why it’s not running or starting. Ik it’s probably the carb not being set properly but me and my uncle don’t have a clue what does what. So if it’s the carb could u help guide me as to how to go about fixing this issue. That’s the whole process from the day I bought it. Sorry for the whole confusion I’m new to this stuff and the rotory scene. I’ve never worked on one till I bought this one but I did a bunch of research before buying it. So Ik a little bit but there’s still a lot that’s confusing me.
The carb needs another go around with cleaning and freshening. Your idle circuit is either blocked or theres a huge air leak somewhere. I suspect blocked.
05-09-19, 02:23 PM
