superbee717

ive recently purchased a 1980 rx7 . it has 79,000 original miles and in good shape. the problem im having is the vacum secondarys are not openingwhile driving. ive changed fuel filter , replaced secondary diaphram with one from a junk yard cause mazda doesnt offer a new one. ive searched high and low for a vacum leak first by using a can of carburetor cleaner then by using a stestascope with a hose attached and have not found any leaks. i can pull the secondarys with my fingers and it sounds and runs great so i know jetts are not clogged and wouldnt think it would be ignition problem. you mazda guys , techs , shadetree mechanics , mazda geniusous got any ideas ? any help would be greatly appreciated. thanks in advance . wanna go cruisin

Kentetsu

If you are certain that there is a problem with the vacuum actuated secondaries, then one possibility would be to switch over to "mechanical secondaries" (search that term).

A great resource for info on these carbs is www.sterlingmetalworks.com

Good luck.




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superbee717

thank you kentetsu , i appreciate the info. was wanting to keep the vacum secondarys for fuel economy but if i cant figure out what the problem is i will convert to mechanical. looks like i will have to remove carb to convert linkage to mechanical . is that true or not ? thanks for the info

Kentetsu

No, you can convert it right on the car. Also, fuel economy can be great with this mod, because you choose when the secondaries open (you can feel the resistance increase through the pedal once the secondaries start to open).

74RX4

iTrader: (10)

Make sure your throttle return is hooked up like this.



NOT like this

superbee717

thank you kentutsu for the info that i can do the mechanical linkage without removing carb. and thank you 74rx4 this linkage i think called the titter totter is hooked up correctly but thank you for your input. i know my post count wont let me see some the links for hooking up the mechanical linkage is there any one who might have a pic of the way you hook up the mechanical linkage ? thanks for the responses im going to go mechanical linkage but i would like to see one before i give it a try. thanks guys

moviestar9594

I'm learning from every post I open up. This is great!

superbee717

yea me too .would just like to see sum pics of a machanical linkage and ill be crusin. proball only a couple posts away

superbee717

thanks for the responses. i really wanted to keep it stock which i finally did after tirelessly looking for a vacum leak. i finally took the vacum secondary off the front of carb for the third time. first i replaced diaphram from a junkyard rx7 even thoug i couldnt see any thing wrong with the one that was in it. second time i took it off for a spring mod. this time and hopefully the last time i took the vacum secondary diaphram off the carb and took my air hose and shot air through the vacum port for the box . bolted it back up and my secondarys work great now.
it just took a shot of air and im crusing and loving my 80 rx7.

Kentetsu

Very cool! Thanks for posting back with your results.