M_D_H

Posted a few threads previously getting some help rebuilding my nikki.
Great news, it's all together and she runs, albeit badly.

I don't have much to go on as far as how these cars run in good condition, mine's had a clogged carb that I don't think was ever serviced in the car's lifetime, and I've never been in another rotary other than mine.

I've got her running finally but I've got a lot of vibration and an unstable idle, the car stayed running for about 5-10 minutes before finally sputtering out, way better than I expected tbh. I'll be draining the old gas and putting in fresh tomorrow, as well as inspecting my somewhat fresh plugs to see how fouled they are - had put a little bit of oil in the motor previously while it sat. I still had pretty bad vibrations and breakups on acceleration as well, I'm not sure how much of that is bad gas and possible fouled plugs, and how much is my questionable noob carb rebuild job.

Other than that, what can I look at? I have fuel dribbling out of only the primary closest to the firewall at idle, I'm not sure if both should be weeping the same amount or if that's fairly normal. Both primaries seem to spray equal amounts of fuel on acceleration.

How can I test the secondaries to see if they are working? They are still vacuum, not converted to mechanicals - not yet, at least. Will the vacuum secondaries activate when the vehicle is not under load? I'm really new to the carburetor world. I have yet to see the secondaries actually functioning and opening.

Is there anything else I should check that's just basic functionality of my rebuild? I'll be messing with the adjustment screws later, I'm just trying to make sure my rebuild is functioning as planned right now.

Benjamin4456

I don't have a whole lot of time here, but that rear primary booster should not be 'dribbling' any fuel at idle if that's what you meant. In that case you have a stuck rear float/needle and that's a large part of your problems. Try tapping - lightly, so as not to break anything - the firewall side of the carb with a hammer or other hard implement and see if that stops the idle fuel drip. If not you'll need to take the air horn off again (the top section of the carb) and inspect/clean/burnish the needles. Did you use the replacement needles and seats from the rebuild kits? They are known to be of poor quality and cause flooding.


The adjustment screws are part of basic systems, so unless you are only trying to get it running at some high idle, you will need to mess with them. I think mixture baseline is about 3.5 turns out to start.

Report back with any progress and I'll do my best to help.

M_D_H

Alright, it's been a few days and I've spent a LOT of time ensuring everything is as perfect as I'm capable of on my nikki.

Here's where I'm at: Starts and runs nearly immediately. I have idle set at a comfortable 900 rpm, and it idles very smoothly. Mixture screw adjusted about 4 turns out. With the throttle pedal fully pushed, the engine accelerates very quickly all the way to redline and beyond, way better than it ever has before, I'm ecstatic about that.

BUT- At part thottle, about 50% and below, the RPM nearly hits a brickwall at about 2-3k rpm. Accel is stumbling and erratic from 1-2, and doesn't want to go past 2.7ish without additional input. This is especially bad while driving around town, this is nearly exactly where the rpm and throttle pedal needs to be to drive at 40mph.

Is this maybe an issue with coils, ignition, rotor/cap or timing?


STEPS TAKEN TO REACH THIS POINT:

Removed the entire carb again and inspected and cleared each needle jet and air bleed to ensure no dirt got in while I had the air horn off previously.

After about 10 times removing the air horn I've got the floats at the proper level - not quite sure why, but one float has to be set slightly different than the other, but the end result is nearly perfect fuel level in the center of the sight glasses.

I fixed an issue with the vacuum linkage to the secondaries, and fixed all my other janky wire connections with proper cotter pins.
Inspected spark plugs with about 1k miles on them and cleaned them gently. I will be replacing these in the next day or two to be sure.

Full tank of fresh 87 and new fuel filter.

Adjusted Idle and Mixture screws.

t_g_farrell

iTrader: (1)

Sounds like your accelerator pump needs adjusting or is not working correctly.

Benjamin4456

Have you checked if the float bowl vent solenoid (FBVS) is working? It should make an audible click when the key is turned to 'run'.

It can cause issues similar to the 2-3k brick wall. I doubt it's the problem, but it's possible.