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Nikki secondary seal, won't drop to idle

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Old Sep 11, 2021 | 02:46 PM
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ME Nikki secondary seal, won't drop to idle

Hey all ! I just did my first nikki rebuild, had water from tank gum up the fuel, lots of white gunk. Cleaned and replaced all parts after blowing channels out, fixed new gaskets as they lacked a few holes. Reassembled. Started right up, won't drop below 1.2k. Been checking all vac lines. Pity there's no clear write up about locations for those. Takes forever to trace each one from FSM docs. The only other suspicion I have is that I attempted to pull the front sec butterfly because there was gunk and corrosion in the housing - and scored the edge a bit. Reassembled so it closes flush, but I don't know. I tried to cover the front secondary barrel to rule this out as my leak, but engine immediately dies. Opinions ?

Oh yeah, I also haven't got the hot start spring in yet, but forcing the throttle closed by hand doesn't help. I haven't adjusted the dashpot or idle speed screw, either. the throttle cable has been ruled out.

I have accidentally double posted. Can't seem to delete.

Last edited by Azederach; Sep 11, 2021 at 03:18 PM. Reason: double psted
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Old Sep 11, 2021 | 03:44 PM
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progress ?

Just found a hole in the intake end of my anti-afterburn hose. Waiting for battery to check results.
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Old Sep 12, 2021 | 02:36 PM
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I am by no means an expert, but I did just spend the last several weeks dealing with issues on my (stock) nikki after rebuilding it...

First off, you say you haven't adjusted the idle screw - try backing that off (turning counter clockwise).
You say the hot-start spring isn't attached - not having that spring allows the hot-start linkage (on the throttle arm assembly) to not sit correctly and could (I suppose) lead to a situation where the throttle is held open. I doubt this is the issue, but I would either get that spring on there (and verify the linkage is sitting correctly and not "flipped over") OR make sure the linkage is positioned correctly and tie the end the hot-start cable attaches to up out of the way (with the cable disconnected).
Your comment about the gaskets in the your rebuild kit missing some holes sounds like the most promising lead. I used a Hygrade rebuild kit and the gaskets were fine (as long as you install then in the proper orientation).
The gasket between the main body and the throttle body in particular is easy to install upside down (guilty!).

Personally the 1200 RPM min idle sounds like a vacuum leak to me, but your comments lead me to pint out the issues above...

Good luck with it!
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Old Sep 13, 2021 | 02:02 PM
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ME Mo problems mo money...

Thanks. Turns out I flooded it, probably by closing of the secondary barrels. My plugs are kind of black (and wet) and I have a burnt coil wire, my cap and rotor are worn, and my 1 1/2yo battery doesn't crank for more than a minute. Off to round up parts.
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Old Sep 13, 2021 | 04:37 PM
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Been racking my brain over that

The gasket that was the issue was spacer to throttle body. I punched out the necessary holes and triple checked the others, paying special attention to the side of the main body gasket that covers the idle circuit - a known issue in these forums.
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Old Sep 14, 2021 | 01:19 PM
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Originally Posted by Azederach
The gasket that was the issue was spacer to throttle body
It's my understanding that the paper gaskets for the spacer (between intake manifold and throttle body) are generally considered unnecessary and even a problem if installed...
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Old Sep 14, 2021 | 03:34 PM
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Originally Posted by Kizmit99
It's my understanding that the paper gaskets for the spacer (between intake manifold and throttle body) are generally considered unnecessary and even a problem if installed...
Correct, there's no need for any gasket between bottom of assembled carb and the black heat sheild / vacuum manifold spacer. It is mostly hard thermo plastic but is rubbery where it meets the carb and intake manifold. It left the factory without any gaskets on purpose.
* It may need something if the rubbery surface is damaged but when good it is self-sealing.

Last edited by Maxwedge; Sep 14, 2021 at 03:47 PM.
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Old Sep 16, 2021 | 01:28 PM
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well...

I put the gasket in there because I found the remains of one stuck to the bottom of throttle body It was kind of gooey and disintegrating.

Last edited by Azederach; Sep 16, 2021 at 02:24 PM. Reason: spelling/keyboard
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Old Sep 16, 2021 | 01:37 PM
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oh well.

Probably going back in to pull it.

Had to replace plugs and deflood after covering carb barrels too tightly. Learned not to do that. Also replaced battery, cap, rotor and wires, NGK plugs were $35 !

Last edited by Azederach; Sep 16, 2021 at 02:24 PM. Reason: content
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Old Sep 16, 2021 | 02:14 PM
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Aaaaargh

Blocking my secondaries 99% with my hand immediately drops the car to idle.


Time to start pulling the carb of my rusted out 85.

Last edited by Azederach; Sep 16, 2021 at 02:19 PM. Reason: addition
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Old Sep 16, 2021 | 03:30 PM
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ughhhh

This doesn't look good.



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Old Sep 26, 2021 | 05:01 AM
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Your pics are a little blurry... is that something from the Titanic?
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Old Sep 27, 2021 | 10:59 AM
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well...

I bought another carb and freed the linkages, and the butterflies seal tight. BUT if I tighten the rear passenger "throttle body to phenolic spacer bolt"
the secondaries stick and so I have a vacuum leak that revs me up to 3k.
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Old Oct 11, 2021 | 11:57 AM
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Compatibility


So I got a new NIKKI. As you can see, though, it seems to have no port for the trailing vacuum advance. BTW, these tiny port holes are the ones my gasket was missing.

Last edited by Azederach; Oct 11, 2021 at 12:00 PM. Reason: addition
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Old Oct 13, 2021 | 02:12 PM
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Improvement !

I repaired my original throttle body with an intact butterfly valve, reseated both secondary butterflies, locked the threads, triple checked all gasket seals and holes, installed everything tight, and now the car drops to ~800 rpm. An adjustment of mixture brought it to 850 or so and steady and even. The only issue now is that it dies on acceleration like the accel pump isn't doing it's job.

Last edited by Azederach; Oct 13, 2021 at 02:13 PM. Reason: spelling/keyboard
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