I have a mallory fuel pressure pump and a stock nikki carb with mechanical secondaries. I was just wondering how to hook up the fuel pressure regulator with the carburetor. Do i need to hook up the return line to the bypass then block off the return line port on the caburetor. HELP PLEASE!

 

The return line from the carb needs to be capped, and the line from the bottom of the Mallory now needs to feed the return line to the tank. Coversely, since I don't know for sure how vital that function is on a Nikki, (any help here, Sterling or Carl?), you could always "tee" the return line, put one of those one-way valve barrels like on the fuel-in side but insert it right between the the tee and the return fuel line coming from the carb (only this time, the arrow needs to point away from the carb...) with the Mallory fuel return on the other side of the tee and the last line of the tee being the fuel line going to the stock gas tank return line....hmmmm...maybe I should draw something...

 

Nah, the return on a Nikki can be capped. If the Mallory has its own return port (Im assuming thats what your saying) then you can feed it to the return to tank line at that point

 

Then option one is the way to go....thanks for the help, Carl!

 

Thanks you BOTH for the help! MY CAR MIGHT RUN TONIGHT!!! If and when it does, i will post pics.

 

I suggest just running the Nikki return right now because it's convienient.
Get the carb tighten in, and then you can mess with eliminating the carb return line and plumbing the pump return.

It's just one less variable if something goes wrong. And with Nikkis, even if it's something really basic, you're in the lucky ten percentile if it all goes smoothly the first try.

 

His problem is that the Mallory pump is going to blow away that Nikki...if he has a Mallory regulator like he's suggesting (the 4309?), it has multiple ports and one bypass on the bottom. Using that bypass is highly recommended to extend the service life of the fuel pump, which is a weighty investment. The return line under the hood is an extremely convenient feature for this set-up.

 

Well, im not in the lucky 10% LOL. I couldnt even pull the damn choke when i went to start it. Turns out i hooked up the linkage wrong... But i got that all squared away and now, yet another problem, im not getting fuel, i can feel air pumping through when i disconnect the fuel line tho, so its probably a problem with the lines somewhere. Does the MSD electronic fuel pump need to be primed somehow b4 it will pump? Also, just to clear things up more....YES, i do have gas in my tank.

 

One more thing, i went with the bypass and plugged the nikki return line, does the fuel pressure regulator need to be set if im only running the stock carb? Geoff (iotus) said that it would probably be fine unless i put a new carb on...Thanks

 

u sure u dont hav ethe pump electric leads hooked up backwards?

 

Well, got the problem solved, after i dropped and cleaned my tank, i forgot to hook the lines back up. (live and learn) But the good news is that she runs!!! Needs a damn good tune up, but it IS running.