gaunt1969

I stripped my carb down, Mech my seconds and the car runs a lot better but I have a hell of a flatspot. If I go from Idle to wfo fast it will even kill it. The totorial said to lengthen the accell arm. Is it talking about adusting the nut out on the rod or makeing a mod to the arm itself and if so with what?

gaunt1969

^

TheRX7Project

iTrader: (3)

WFO? Wide ******* Open? It's still a carb... and when you "punch it" it dumps a bunch of fuel in at once. It's probably richening so much it dies...

OR could be the exact opposite problem, maybe you're not getting ENOUGH fuel for all the air suddenly rushing in, and your carb runs dry.

glewsRx

iTrader: (1)

Put an extra gasket in the accel pump like the sterling mod thread says. It will make the shot bigger.

Glazedham42

iTrader: (4)

You need to go back and re-read the writeup that Sterling did. You obviously didn't find the whole version that he posted here, or else you skipped through a lot of it. The purpose of the accelerator pump is to provide a quick dose of fuel in the event that you go wide open on the throttle. Remember that the Nikki carb is originally designed for vacuum secondaries, which operate somewhat slower than mechanical secondaries. With mechanical secondaries, if you punch the pedal all at once your engine is going to fall on its face. There is too much air all at once, and not enough fuel to create a proper mixture. You will never be able to stomp the pedal with mech secondaries, but there are some things you can do to get yourself extremely close to that point.

I have properly adjusted my mechanical secondaries to the point where I can swiftly put the pedal to the floor. I can't stomp it, but I can step down pretty fast still. Do the following to fix the issues...

As GlewsRX said, you need to double gasket the AP diaphragm. This will increase the volume of your accelerator pump shot. Also, you need to lengthen the AP arm, as you mentioned. This does not mean just adjust the nut on the linkage. You need to make a small bracket and attach it to the existing linkage for the AP. Making the arm on the AP linkage longer with increase the stroke of the accelerator pump. This is also going to help you get more volume into the carb. See the writeup below for more details on the AP lengthening arm...

I have attached a link to Sterling's writeup here...

https://www.rx7club.com/showthread.p...threadid=62678

Read the WHOLE THING..... TWICE at least! Some of the terminology is a bit confusing until you know the ins and outs of the Nikki carburetor. If you have questions AFTER having read through all of that info, post again and I'll be happy to help out. I can provide pictures for you too if necessary.

Good luck, the mod is worth it.
Jamie

gaunt1969

Thanks thats what I needed Glazedham42