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Conner

Nikki Carburetor Auxiliary Arm

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Hey guys.  

 

I finally got my rebuilt Nikki carburetor re-installed.  

On the rear (firewall) side of the carburetor there is an auxiliary arm with a weight on the bottom.  I'm not sure I have this set up or oriented correctly.  Here's a picture of the auxiliary arm in the down position (my finger is on the weight):  

 

aux_arm_down.JPG

 

When the arm rotates into the "up" position there are a couple of tabs that collide, one on the auxiliary arm and one on the throttle mechanism, so that the arm's upward rotation moves the throttle.  Here are the two tabs:  

 

aux_arm_up_tabs.jpg

 

I'm confused because those two tabs really only can intersect when the throttle is applied or the choke is pulled.  Otherwise, when the auxiliary arm rotates up it doesn't do anything.  

 

What is the purpose of the auxiliary arm and when it moves into the up position?  

Can anybody confirm that I have it set up correctly, meaning it only hits the throttle arm when the throttle (or choke) is being applied?  

 

Thanks!  

 

 

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Looks like the throttle cable in 90* out of alignment

 

 

OOOPPPS that was the choke cable

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That tab sticking out on that weighted arm is supposed go into the "V" shaped tab on the other arm only when the choke is pulled on fully, if it doesn't fit in the "V" then your carb has been put together wrong.

DSCN7064_zps4xv7t9h2.jpg

I believe that weighted arm is controlled by the vacuum created when the pedal is floored so it should move freely so it can open when floored, but when the choke is pulled on full it pins that arm(butterfly in the secondary) shut so the choke works properly when the pedal is floored when starting the engine, again that arm should move freely and it should be in the down position(first photo of yours above).

You see if that arm/butterfly was not there then when one floored the pedal the secondaries would be wide open during starting cold in the morning, it would defeat the purpose of the choke unless the choke covered both the primary and secondary ports at the top of the carb, but only the primary is metered.

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That's great.  Thanks, Wayne.  

 

That's how it is set up and I wasn't sure if it was right.  Thanks for confirming how it works.  

 

I appreciate it!  

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Fact is I am happy this subject came up, it made me look at the extra carb I pulled off my L320 that would not start worth a shit, it turned out that the L320 carb was put together wrong by the guys that rebuilt it and I wonder now if that is why it was hard to start, but it didn't run that good either, so I put a Weber on it and it starts and runs great now.

But I never would have figured out mine was put together wrong because it was "out of my life" until I seen this thread and went and had a look at it, thankyou, I learned something today.

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Conner did you have a rebuild kit? Do you mind if I ask how much it cost to have it rebuilt?

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Sure I had Chicago Carburetor rebuild it for me.  They in turn sent it off to some other company on the west coast that does rarer carburetors for them.  I may be able to find out the name of that shop but would have to look.  It was in the $200 range. 

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If you could get me that contact info that'd be great, thanks for your help!

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The name of the company was J&J Carburetors out of Fullerton.  I'm pretty happy with the job they did.  

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