freddytums

Hello! First post
I've just decided to start getting into working on my Nikki. I'm currently converting to mechanical secondaries and also doing the accelerator pump mod. I've been following Sterling's written instructions and also referenced a picture from someones else's mod I found, I'll include links to both of these below. I am currently doing trial and error with the length of the bracket extension. I've found that with my first attempt I made the following easy to fix mistakes.

1) The hole I've drilled for the accelerator rod to attach through my custom bracket can't just be cut as a circle but will instead need to be more of an oval so that the lever is able to complete its full arc without binding (essentially I need to give it wiggle room while not allowing the nut and washer to slip through).
2) I may need to make my custom bracket slightly longer in order to essentially "time" the Accelerator Pump and the Throttle together.

These are the couple of questions I have . . . (Any other tips are welcome! I'm having a ton of fun learning all of this!)

A) Should the accelerator pump finish it's full pump at the same time as the throttle reaching full rotation? (Primaries and Secondaries fully open)
B) Has anyone else who's completed the AP Lever extension found a length for the extension that worked the best? My current extension length I am trying with is 1.1"

Sterling's Written Guide
Reference Picture

Here is a picture of my current extension with sharpie marking how I'm going to make my AP Rod's hole a little wider.
My Bracket

Benjamin4456

I believe the general rule is a 1 1/4" center to center spacing on the holes. I have mine adjusted such that it starts depressing the AP diaphragm immediately but doesn't quite reach the end of the stroke by the time the secondaries are fully open.

​​​​​In theory you want the perfect travel such that you get as much volume through as possible, but mine is close enough that it's fine. My idea is that the last little bit of the stroke doesn't give as much volume as near the middle of the stroke and so my way is actually more or equally as optimal, but I've never proved that. I might be crazy thinking that, but I haven't had a major issue yet due to it. Reasoning for this is that my secondaries are re-timed and open at the very end of the primary travel, so I try to save some fuel for right near the end.

Essentially go for 1 1/4" spacing and you'll be fine. If you want, you can always make the attachment hole (the one you bolt to the factory arm) a little oblong so that you can fine tune it.

Oh, and welcome to the forum! There's a lot of great info and advice you'll find here.

freddytums

Awesome! Thanks Benjamin, I'll move forward trying to position the arm to get the most pump possible.