MosesX605

You may or may not have seen my thread detailing my problems with my recently rebuilt Nikki. In the process of fixing it, I bought another Nikki for comparison's sake. Now I've got another carb just laying around, and I was thinking to myself...

Maybe I should build a racing carb!

I've gotten pretty good at taking off the carburator thanks to the week of troubleshooting, so I figure, maybe I could clean up and rebuild the other carb, and then try some mods on it, like mech secondaries, Sterlings accell pump mods, and the like. But I wouldn't want to stop there. I'd want to rejet this carb as well, which brings me to my questions.

Where does one find new jets for the Nikki?

What jet sizes do people run in the Nikki with good results?

What other modifications could I do to the stock carb to extract more power?

I'm all ears here people. I want to know what you have all done to your Nikki's to make more power.

REVHED

The venturis can be enlarged and parts of the carb like the throttle plate assembly and airhorn can be machined to flow more air.

Sterling

-You could send it to me to modify.

seanrot

iTrader: (2)

I could send it to you to modify but what would you do? I have an extra 1980 carb sitting that Im going to rebuild and put on the car.

Sterling

O.K.-
It costs $300 plus S&H, and this is what you get...

- A carb that I would put up against Yaws carb. To some that may be a bold statement, while to others they might just shrug and say, "Ehhh.". But I'll even go so far as to say that I take the carb one step further than Yaw wanted to spend the time doing, and I believe I pay more attention and effort to flow dynamics. (He does'nt do anything to the airhorn, for example.)
The end result is a cleaned and modified stock carburetor with all emissions **** removed, rebuilt with a new gasket kit. It will breathe at least as well as Yaws carb, but probably better. I'll be having it flow tested by someone we all know and trust, too. More about that in threads to come.

All emissions tubes will be permanently blocked off, unless otherwise requested. This means I pull out the metal nipples, and plug the holes with brass inserts or JB weld. (My choice) I leave the dizzy advance vacuum tubes.
You also get air bleeds and fuel jets.

This is some of what I'll do-
First I completely break down your carb. I mean completely!- booster venturis are removed and primary venturi sleeves are tapped out. The air horn gets the Foredom flex shaft (I'm a jeweler, so I've got some really cool tools for this stuff!) The idea is to remove all tabs, ledges and restrictions. It's an easy concept, really- you just have to imagine water has flown through and worn away those things and made everything smooth. I just do what makes sense, and take it to the limit that I can.

Everything gets cleaned like new, and then I take the throttle body, main body and airhorn, reassemble the three and go to a friend for bead blasting. The circuit holes get plugged, and the venturi sleeve holes get taped for this. Bead blasting puts a nice finish on the outside, and acts like a final 320 sanding on the inside. It's just fine enough of a surface for me to polish with the flex shaft again. So only the outside is left beaded. The inside is smooth.

The booster venturis need to have their support arms removed, and then there's some shaping of what's left into a textbook airfoil design (a step Yaw does not do). They are polished, also.

The primary venturi sleeves are put into my Sherline lathe (the same that Yaw uses) and I bore them out as far as they will go but still maintain useable foil shape. If you go too far, they'll be useless. Again, the insides are polished by hand with a flex shaft.

The throttle shafts are removed, and material is milled off where the butterflies are screwed on. This allows less restriction of flow. Low profile screws are used during reassembly, and the ends are crimped to ensure they'll never come loose on their own.

During linkage reassembly, I reinstall only what is necessary for the carb to operate. This significantly slims it down and "decomplicates" things. Retaining the choke, as well as the vacuum secondary actuation is the owners choice. And I can offer "no choke" or "partial choke" as an option, and mechanical secondaries as an option to the vacuum box.
No choke just means I yank it all. I've run my Yaw (which I've further modded) with no choke for nearly two years now. I don't have problems even in the NY winter. If you feel you need a choke, I prefer to leave the lesser "partial choke", as this just means I leave the butterfly and some linkage in place, and you have to hold the choke open with the **** for it to work. It removes alot of crap, you still have your choke, and you can install easily any number of after market air filter options. But be forwarned, leaving that gigantic flap of metal at the top of the airhorn WILL impede flow!

I modify the accelerator pump by attaching an arm that gives a longer travel, and I increase the housing gasket thickness to give more volume. The details of this mod are outlined in the archives under a thread I wrote entitled, "Carb Crap, Nikki Mods". I feel it makes a huge difference in throttle responce throughout the entire range. The basic idea is that the stock AP does not continue to deliver any fuel shot when you are at partial throttle cruise, and want to nail it without letting off the accelerator as in down shifting. I had stumbled onto the idea as a remedy to the bog usually associated with converting vacuum secondaries to mechanical, but found that it increased the throttle responce so dramatically, I now concentrate on it as a great mod in and of itself.

I tap the tops of the emulsion tubes, and supply a range of Holley air bleeds that will fit, and thus help you to truely dial right in on whatever tuning curve you desire.
Fuel jets will be supplied, too, of course.

The throttle body will get painted for a spiffy look-the colors I have not yet chosen. (I'll offer five or so. Not going hunting for special requests on this.)

Each carb gets my initials stamped on the throttle body, main body, and airhorn, along with a serial number. The serial number gets entered ino a computer file with all the mods done, special requests, date, owner, ect. That means that after sales tech support will be available for the purchaser and will follow that carb even if it's secondhand!

The options offered on my carbs will grow as I experiment and recieve feedback from purchasers. If your carb job is just a simple rebuild with all emissions mods kept in place, or an all out street rod mod, you'll get the same attention to detail and the same after service tech help.
Also, as I make new discoveries and developments, I will send tech "how-to" articals to all on my Emailing list who paid for mods. I also intend to bank my tuning articals and other findings on this site, Mazspeed.com, and soon my own site which will either be run with Carl Rx7 or at least linked to his own site. This way, anyone with a Nikki carb can modify their carb to some extent. I believe most will find it a very satisfying experience, and they will look at their carbs and wonder what more potential is locked within.

I will be setting a return policy, and a "return finished service date" policy, as well. What this means is I will have a certain number of weeks to complete and send the carburetor back.
I have NOT DONE THIS YET- Sooo; I need to start high, and set policy for 12 weeks. Now I don't really think it would take 12 weeks even if a hurricane ripped through my house. But until I gain experience in customer relations and just plain reality of doing all this, I'll need patience from my customers.

The other part is that you have thirty days to decide you don't like it. But I'll need 60 days from the date of return to get you your money back!
Sound fair? -No? Well listen- this is the reality of covering your *** and making sure you don't **** people off. I want to be known as a man of my word- one who delivers what he promises.
Promising I'll be late, but I will come through is much better than either promising what I can not be certain of, or making no promises at all.
These conditions will certainly change for the better in the future.
I have four carbs started now. You send me your carb, I inspect it, and make sure it's good. What you get back MAY OR MAY NOT BE THE CARB YOU SENT - unless specially requested. This helps to expedite the process. If I only get a few orders a month, then I should be able to have one ready to go.

Things that you need for this carb to actually work...

A high pressure fuel pump- I use a Carter 7-14 pounder. It's a pain to install, though I don't know how it rates in installation compared to others.
I use a Holley 4 psi regulator. It works great, and is inexpensive enough.
The carb is happy at 2.25-3.75 psi.
And you need a fuel pressure gauge, too.

Direct inquiries to Sterlingcarb