So now that I have my 1980 RX7 setup with a Nikki carb that is stripped down it runs and idles well. But after driving is for a while it seemed to me that the power was lacking. So just checking with a simple test and pressing the accelerator to the floor I can see that the secondary's are not opening. I have rechecked all the mods and can not find any vacuum leaks and I have tested the diaphragm and it seems OK. Is there anyway to increase the vacuum after stripping the carb to get the secondary's to open without going to the mechanical setup?

 

Pushing pedal to the floor while in neutral won't open the secondaries. I think you have to be in 2nd gear and have some load applied. There is a procedure in the FSM.

 

Thanks for your reply, I should have said in my post that I connected a long endoscope camera thru the air cleaner to the top of the carb so I could view the action while driving. This was my "simple test". But I will re check it again and review the FSM post.

 

Did you rebuild the carb at the same time? If so, you might have installed the gasket between the throttle body and main body backwards. Take a look at this post. https://www.rx7club.com/1st-generati...issue-1152653/ Turns out his was backwards. With the gasket backwards the secondaries will not open. Ask me how I know (or don't bother, because you can pretty much guess).

Carl

 

On top of what Carl said, did you remove the venturis when you stripped the carb? If the primary venturis are not aligned properly, they will not provide the required vacuum signal to the vacuum secondary opening circuit.

I believe the secondary venturis also have holes on the 1980 carbs, but misaligning these should actually improve the vacuum signal to the vacuum secondary opening circuit.

 

If you installed the return spring wrong, that will mechanically prevent the secondaries from opening. There is a safety spring on a rod with a T on the end, the T has to go over the end of the pivoting bracket that holds the return spring.



The idea is, if the return spring breaks, the bracket flips up and the safety spring is allowed to extend. This will prevent full throttle/secondary actuation by design.

 

thanks, Carl
I am sure its OK because I knew about this issue when I was rebuilding the carb

 

Joekaistoe,
thanks, did not remove them during rebuild but does not hut to check.

 

peejay,
thanks but I do not have it wrong, That would have been a welcome fix.

 

Multiquote to the rescue! Use this button to add several messages to your reply, saves you some hassle

 

get more posts(count) doing it individually like that. lol

 

Make sure to let us know what you find that fixes the problem. It will be good to the list of possible causes for the future.

Carl