Hey Nikki owners, what's new besides the fact that you can't figure out what's up w/yer carb?!
Well I gotta say after reading about half a dozen very recent responces, but over a dozen in the past few weeks, about resetting float levels, this is, IMO, bum advice for Nikki owners.
Lookit guys, float levels don't just **** up on their own, ok? You have to bend a tab on the bowl for them to change, so unless you've tweaked the **** outta yer floats or played frisbee with yer airhorn with the floats still in place, LEAVE EM BE!
Unless during hot idle your fuel level is not at the halfway point in the sight glass, there's no need to adjust. Moreover, if the float by the firewall is set too low, the accelerator pump won't be able to draw in fuel to give a shot when you press the pedal. Because without an inspection mirror you can't even see that glass, you won't even know.
It's silly **** like this that'll leave you scratching yer head or throwing wrenches.

Not sure if their tweaked?
Assemble them with gasket in place and hold the horn upside down. The tops of the floats should be almost level without pushing on them. They should measure 9/16ths inches from the gasket to the top. If they are not visibly tweaked and way different from each other, I suggest you don't get into making yet another troublshooting variable for yourself.

Float level is important because the circuits in the carb are designed to work at a certain fuel level. Emulsion tubes begin to expose their emulsifying holes at certain levels. Changing the fuel level will THOUROUGHLY SCREW UP YOUR CARB!

I'm telling you this cause I'm a nice guy. I could just wait for you all to do it and wind up with some REALLY EASY business!

Troubleshoot troubleshoot troubleshoot!

Flooding wildly? Is yer floatbowl solenoid hooked back up? This is a magnetic plunger that shuts off your carb vent when there's no juice to it. It's only for emissions control...and a roll over. When there's no juice to the wire to pull that plunger out, your carb gets all screwed up. A disconnected vent solenoid can cause flooding and a variety of other bizzare ****.

Idling way too high?

Tired of hearing about possible vacuum leaks? Too bad...check again. But be smart before you look for the ever elusive, often invisable vacuum leak...

There are other sources of "high idle syndrome"-
When you gitty little girls go to reinstall your newly built carburetors either all drunk from a hard days beer, or just so excited that you might wet yerself, you often overlook the simple ****, like proper accelerator cable adjustment. The damn cable's too tight, and your primary butterflies are cracked open. Listen- all my textbooks say that even the most experienced carb guys will have to admitt to doing this at least once!

There's a wonderful lil thing called a "deceleration dashpot" over the linkage clusterfuck on the right. It has a white button on the bottom that acts like a mini shock absorber and makes contact with a big tongue hooked to the primary throttle shaft. This lil puppy helps ease the throttle down to idle so the transition is smooth, aids in keeping backfire at bay, and even could be argued to help keep RPMs up while shifting like a lunatic.
Well, if this got bent, or doe'snt operate smoothly, it's another possibility for high idle. It's adjustable, too.

So is your AC valve...that big black plastic thing, folks. That's an idle compensator for the drag on your engine that the AC compressor gives. But if somethings fukt with yer system, it's a possible source.

Brake booster...here's a GREAT source for high idle. a pair of vice grips on the hose will tell ya, but don't go driving it like that!

Guys, it's a damn carburetor, not a Swiss watch. Think of it as plumbing. You can't get good water pressure with a leaky system. All it takes is one vacuum leak to throw off the idle circuit so much that the car simply won't run on it. When you up the idle screw to compensate and are idling @ 1800 RPM, you're actually using the main circuit to idle your engine. Problem is there's not enough vacuum present for that to give a good mixture (hence the idle cicuit in the first place). That combines with your vacuum leak and makes for a very lean mixture. So you go playing with the idle air/fuel **** to try to make it right, and when you finally do track down the problem, your carb's so outta whack that you don't even know if what you found was the problem!

Another peeve of mine is when people decide to rip out the rats nest without doing some research. Carl and Pratch worked VERY long and hard on a great tutorial that would help with an awful lot of questions, and alot of resulting carb associated problems.
A great example is people not bothering to research, and so not retaining the PCV system. PCV means Positive Crank Ventilation. I can't count how many damn times I've had to explain this.
If your mixture is perfect for your load (never is), then the resulting chemicals from gasoline cumbustion are carbon dioxide, nitrogen, and water. But because the mixture can't be perfectly controlled for every load and conditon, ect, - even in fulie engines, you get carbon monoixide and nitrogen oxides as well.
But you still get water.
The water gets into your crankcase, and oil. In your oil are microscopic spring like additives. When cold, these spring like additives contract...around water molecules. When the oil is heated, they expand, releasing the water molecules, which turn to vapour. This water vapour is supposed to be sucked out of your crank by carb vacuum. It does not hurt the engine or performance. The PCV valve regulates the vacuum the crank sees, and also serves as a check valve. This system is also hooked to the charcoal canister. The charcoal canister serves as a temporary water vapor holding tank. As it heats up, the PCV will allow that into the carb, too. The water comes from water naturally found in stored gasoline, as well as condensation from your own tank.

If these things are not retained, your oil will quickly get to its water saturation point, and the additives will probably break down faster than normal, though that's just a guess. You will develop a white emulsion of oil and water that sticks to the inside of you crank and oil filler spout like glue. Your spout will begin to rust, and this will be much much worse for you folks that don't run the **** outta yer cars and get them heated up well. Even after doing that, the condensate will return to the crank as the oil and air contract during cooling, causing an ever so slight vacuum that pulls in that nice cool night air...air that's laden with water vapor, and so the cycle begins again, contributing a little more water that stays in the system each time.

This is NOT a source of a vacuum leak. The vacuum signal is a very soft one from the carburetor mainbody. Cutting that line and leaving it unplugged would only allow unfiltered air into the carb, nothing more.

With all the experience on this board, and with the volume of carburetor problem questions, a good "sticky" would be a thread dedicated exclusively to troubleshooting the Nikki carb.

Sterling

 

You should have your own sub-forum!!!!!!








Laterz, Andrew

 

the rant was great, but what I love is his sig!!! The last part is SOOO true.

 

Yeah, you could call it "Condescension.com".

 

That's so perfect. Sterling may know a bit aboot carbs, but be's a self-acknowledged *****.

 

I wouldn't call him a *****. If he was a *****, he wouldn't give a **** if anyone was screwing up their stuff, and he wouldn't want to help anyone. I've learned a lot from him, and I, for one, really appreciate his info.

Sterling - Don't get a big head from this, now!!

 

Pppppffft...I don't care. You either like me or you don't.
But even if you don't, you'll probably read what I have to say when it comes to the Nikki.
"Condescending"...heh heh- I get called that even after I try to show everybody on this forum just how humble I really am simply by admitting that I don't know jack about anything else but that stupid carburetor!
Wankelguy and others might see my delivery as condescending, but that's because they already know all this ****.

I'm not trying to condescend anyone at all. But when you give made-up advice because you can't think of anything more to tell the guy who's having trouble, well, that's bum advice.

Telling a newbe to reset his floats will just lead to frustration!

...& by definition of of the word, even calling someone a "newbe" makes me condescending.

Oh well. Take it or leave it.

 

The latter part of his sig hasn't happened to me yet.

That's some great carb advice, Sterling. Now I don't have to feel so carb stupid anymore. I also liked your ATF rant thread.

 

Well put. But, if I actually disliked you, I wouldn't even bother with what was meant to be food for thought. You and I actually have a lot in common, except that I know how to spell "Tourette's".

 

...it was'nt in my Marriam-Webster program!

-but you can bet I'll change it before I go pissin' someone with Tourette's off...

"ACKK..HONDAHONDA!"







Jeeze...could'nt even spell right a second time! (edit)...

 

Made me feel like a second-class citizen all over again!!

Great stuff..humorous in a dark vein and highly informative at the same time...

 

I coulda just summed it up in one word;
"SEARCH!"

...but then that woulda turned people off.

 

I like your ranting, its funny .

 

I had a slot-racing friend who had Tourette's, he would alternately cuss and make kissy faces at me while we were racing. Most disconcerting.

 

 

Nice writeup Sterling. Useful and will comin handy no doubt to many peoples.

What do you think of taking the charcoal out of the charcoal canister and filling it up with Damp-Rid to Absorb all moisture that comes into the cannister?

Empty water from cannister and refil with Damp-Rid when needed. Biggest reason I'm asking this is during restoration of my REPU the charcoal cannister (located in the bed above gas tank) got filled with water and rusted inside. Looking for a good replacement of some sort. Can I buy a hunk of charcoal anywhere?

Welcome to DampRid.com!

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DriveFast7- I'm in no means an expert on this but if I recall from my old Army medic days Charcoal (or activated charcoal- which uses o2 to activate carbon) ADSORBS things. Mainly organic stuff (like fuel vapors and other nasties and the like). It traps organics by a chemical bonding process and (if I recall) renders the nasties benign. This is different than absorb which is basically a sponge which accumulates things (mainly liquids or such).
With that being said, I think the cannister in the Rx-7 would have a primary purpose of adsorbing fuel vapor, and as a secondary benefit trap or condense water vapor as well. I think if you fill the cannister with an absorption material it may accumulate fuel vapors. You could wind up with a buildup of serious gas fumes which like everyone knows, is really really bad. (You know-never let gas soaked rags accumulate in your garage!)You may wind up with a little surprise. (Please don't flame me out- I'm not 100% sure on on this. If any one else can shed more light on this, please do. )

BTW- helluva write-up on the carb Sterling!

 

very good point Tom.

 

Absorbers - charcoal...I really dunno. I don't run one. (aww flame me if ya want, but then...I'm not bitchin 'bout my PVC system, either! :P: )

I'm gonna guess, though, and here it is;

Get another charcoal canister.
I have an 88 Volvo DL wagon...the one that looks like a brick with wheels. I got it because the guy said, "If you can start it,..."
Well, the in-tank pump wires had gotten wet and salty and corroded. I jumped the wires (BAD BOY- I know) and voila.

I think that it was just a terrible location for your canister, that's all. I don't think it was'nt working correctly, I just think it got wet.
The ones in the engine bay are kept nice and warm...easy for evaporating anything that does condense in there.
However, if your PCV system is working correctly, then you really should'nt see alot of condensation there.

 

Well put Sterling, now lay off the coffee!

 

thanks sterling... now if i just knew what half of those words meant

 

You could use some activated charcoal meant for aquarium filters to replace the charcoal in the canister.
It's like $4-$5 from the tropical fish store. I'd rinse it off first, and let it dry to minimize the dust.

 

Ahhhhh heh heh heh...You guy 'er gonna laugh.
At me.

I have to go on record amending (ahem) my original statement regarding floatbowl levels being "left alone". I stand by that statement as it pertains to troubleshooting carburetor problems with carburetors that were known to have provided good operation prior to the problem, that were not rebuilt just before the problems started.


I've done alot of carbs, but only for myself and friends...nothing I was charging anything more than beer for. But now I'm doing carbs that I am charging for, and I become a meticulous perfectionist when I'm working on something for someone else for money - be it a custom knife or gold bracelet, or a carburetor.
I'm now measuring things that I used to just eyeball...like the float level and float drop.

This is what happened...
When I strip carbs, I pitch all the needle and seat assemblies into a tackle box filled with old parts. (I'm so compulsive, even the old parts have their own sections!) I had noticed three different styles -presumably from earlier carbs, later carbs, and one that had been rebuilt at one time. I never gave it a second thought, and did'nt bother to study those differences...until tonight!
Well I went to install a new set into a simple rebuild job, and the parts box was open. The old, worn and varnished assemblies still glitter in the light, and they caught my eye. The big "Yer Gonna Eat Crow on the Forum, Dude" lightbulb went on over my head immediately! I saw how big and fat the head of the needlespring contact pin I was installing was compared to an old one that had a very low profile pin.
I put the new one in the seat and installed the float and measured by eye, and then switched to an old pin, and sure as ****, there was a noticeable difference!
(The higher pin head makes the float level lower.)

Soooooo, ]Ahem[, if you think the carb was fiddled with, rebuilt, or you know for sure it was, then float level *cough-cough* could very well be a problem for you. The difference in float level would have to be outrageous.
Unfortunately, the difference between the two most different assemblies I have was...outrageous!

So folks, when I screw up, I do say so! But I do stand behind the idea that if the carb was working at one time and it has'nt been cracked open since, then float level pro'ly aint the problem.

...O.K...(bracing for impacts)...Lemme have it!

 

I have run into the exact same problem with rebuild kits. Earlier this summer I was rebuilding a marvel-schebler carb for an old farmall tractor(real easy)..Set the float to specs, hooked her up and it flooded like ****. Took off the carb like 5x trying to figure out what the hell the problem was.. I was ready to throw the carb in the field and bushog the sob. Finally tried putting the old needle and seat back in, she fired right up. I took the carb apart again, looked at the difference and it was freakin HUGE. You get no bashing from this country boy..Been there, done that!

 

I love it. In the very same thread we get two things we've all come to expect from Sterling, and one that most of us probably figured would happen if needed, but I for one never really expected.

First, we get the rant.

Second, the rant is actually a well disguised wirte-up full of helpful hints.

Third, we actually get to see Sterling call his own mistake, and own up to it.

I love it. A man who knows his ****, has the atitude to go with it, no matter how much **** he gets, and the ***** to say when he's wrong. Even after he just got done saying how absolutely sure he was that he was right.

Props to Sterling. And for anyone who still thinks he's condesending (I know it wasn't all that serious) F*CK 'em if they can't take a joke!

Brian