Even though your method wasn't scientific, it shows how even a small enlargment of the primary venturis makes a big difference in power.

I have some questions for you. When you open the secondaries, is it a transcendent experience? If so, it means your primary venturis are too small. If they were bigger and made more power, the difference you feel when the secondaries open would be smaller and less noticed.

What size are your primary fuel jets? How does it look on the wideband?

 

Transcendent is a good description for sure. Its like hitting boost on a car with a big
turbo or smashing the button for some NOS spray. They probably are too small or
I can go bigger on the jets. Right now the primaries are 105s and the secondaries,
I can't remember right now I want to get a WB setup because I have the bungs
already at the end of the dual tubes of the RB SP middle section. I saw where AEG
came out with a dual WB with leads and bosch sensors, soo maybe in the future.

I'm pretty sure I'm a bit lean on the primaries based on plug color and exhaust
tip color. The secondaries seem to be great.

I still get 24 MPG almost all the time except in the mountains with spirited driving
where it will drop to about 20MPG.

 

105 is probably ok, but it also depends on your primary short slow air bleeds. It also largely depends on your primary venturi ID because obviously the bigger they are, the more air they let through, and the bigger your jets would need to be. For example Jingkun's carb got a set of 22.3mm and all I had were a set of Holley 51s or about 129 or 1.29mm which is a bit on the big side. I think his carb would do better with a set of 122 to 125 jets, but again this is also based on his short slow bleeds which I drilled to 118 or 1.18mm or .0465". His carb, as delivered from that SVT guy, had a set of 140s or Holley 55. That sounds pig-rich until you realize that he was just following Sterling's tuning scheme which didn't change the short slow air bleeds. Ths stock short slows in this carb were 170. That is a LOT of air and part of the reason why this carb didn't want to idle right. Sterling ran into all kinds of idle issues as well. Well, duh. Especially when you don't have a choke on a cold engine with crappy venturis and all other kinds of problems.

In short I was just curious what size jets you were using but without knowing how big your venturis actually are, and also not knowing the status of your short slow primary air bleeds, I shouldn't try to give any tuning advice over the internet. If I knew most of the specs I could make an educated guess. But the important part is it does run and you seem to be on the right track with it.

Next question: Is it hard to start when cold? And do you have to keep your foot on it when it's cold?

 

Mine is not a big boost when the secondaries open. I attributed that with the secondaries only being slighter larger than my new primaries.

Looks like thats how you figured it too, neat!

 

Nope, starts right up unless the air is little cool out but then I just pull the choke
out (fast idle now) and it will run like that fine until it warms a bit then I either
push it in or its already in. Very streetable.

My air bleeds are whatever is stock for an 83 nikki. In fact all the jets are stock
except for the primary and secondary fuel jets in the bowl. I can definitely go
richer, just havent taken the time to do the change. As you point out, I would
probably have to adjust the air bleeds as I go larger.

 

Oh, ok then you probably have 170 short slow bleeds. See if you can grab a set of SA 150s for now. They will make the carb work better. If you can't find any, don't worry about it. But eventually you'll need to go smaller to around 118 like I do because I've found that size works great even for stock 20mm venturis with no choke.

As for your main primary air bleeds, they are 70 and should be perfect for anything you do with the carb.