rotary_X7

So i just rebuilt my carb and installed it to find fuel overflowing out of the top vent.

Took off the top of the carb and checked float levels and they were at the right heights from the top and bottom. Re-installed and still overflowed...anyone have any idea why the floats aren't stopping the fuel???


I'm really boggled as to why it's not stopping fuel.



I took off the floats and blew compressed air through the fuel inlet and the floats bounced evenly up and they are brand new and are in perfect working order.



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rotary_X7

I dunno wha the hell was up with it...the floats probably weren't seated i imagine.

i started it and now it won;t run below 4000.

What can be some causes of this? Vacuum leak? Too dark to see if something is up with the throttle linkage but i'll check tommorrow.

Any ideas guys?

Jozay721

sounds like a vacuum leak to me.....but not sure...how are all ur gaskets? make sure there not pinched..and also make sure all the bolts are tight...if u took everything apart on the rebuild u might have to adjust the idle mixture screw and idle adjust screws...just some ides....

Rx-7Doctor

iTrader: (13)

Did you remember to plug the air vent solenoid electrical connector back in?

rotary_X7

Yes everything is hooked up properly. I tried to adjust idle and mixture and it didn't do anything when i turned it. Turning clockwise richens? or leans and on which one. I can't remember off th etop of my head at the moment.

Thanks guys.

Kentetsu

Is the base plate (or whatever its called) installed correctly? This is the plate at the base of the carb, with all the vacuum nipples on it. Sometimes it gets flipped upside down and causes vac leaks.

The fuel bowl vent solenoid is on the driver's side, right behind the alternator. A single wire that gets plugged in. Very important that it is hooked up.

Also, some times after a fresh rebuild the float needles are a little sticky. You might want to try banging on the top of the carb with a plastic mallet or something similar to see if it frees them up.

Good luck....

rotary_X7

The phenolic spacer is installed correctly...is there a gasket that goes in between the top of the phenolic and the base of the carb??? I put one in anyways...but would that cause a leak of some sort??

All wires are hooked up.

Jozay721

that spacer comes with built in gaskets...u cant replace them i think...take the ones u put on off and then try it...this coul be ur problem...

rotary_X7

Hey Jozay can you send me some pictures of your modded nikki??

bstrange99

I agree with the good Doctor. You may have it plugged in, but I'd bet it doesn't have 12 volts to it. Try running a jumper straight from the positive battery terminal (just to test it, not as the fix) and see if it stops.

Good luck

rotary_X7

Thanks i wil do that in the morning first thing.

If it doesn't show 12V what would you guys reccomend i do?

rotary_X7

Si got it running...the floats aren't seating worth a crap though...i have to pinch the fuel inlet line to get the float levels down to the right levels.

Also my dashpot decided it didn't want to be on the assembly so the screws stripped out...do i really need it? Doesn't it just dampen the throttle return so it doesn't dfall below idle rpms?

Also can i just leave the float bowl vent open to atmosphere...or with a breather at least?

One more question. When installing the choke lever back into the bi-metal spring do you have to have the choke fully closed?

While the engine was on it was running really hot in the exhaust...the cat was smoking O_O. Yikes...the exhaust coming out was way hotter than before i rebuilt the carb...hotter means leaner correct?

Thanks guys.

rotary_X7

bump...need some answers please.

rotary_X7

No one wans to get their post count up i assume? o_O

Kentetsu

Hot exhaust could be due to retarded timing, or no spark on leading...

rotary_X7

no it was due to a vacuum leak on the intake.

I re-adjusted my floats and now it floods like crazy. =[

Jozay721

man u need to take ur time and adjust them good....how are u adjusting them? doing it with the small ruler that comes in the kit? glad to hear some of ur issues been fixed...

trochoid

iTrader: (6)

Floats rarely, if ever need adjusting. When setting them, make sure you are including the gasket in the measurement, then make sure you didn't scratch the contact surface between the tang and the float.

There is another female connector that can be plugged into the solenoid. Make sure you have the right one.

rotary_X7

Thanks for all the advice guys..getting very frustrated with this. This is my DD so i am suffering =[.

I will sand the tangs on the floats with some fine grit sandpaper. I hooked it up again today, jut now, and i heard the air vent solenoid click and turn on. about 5 seconds later i heard the oh so familiar trickle and sputtering of fuel in my carb throat. I will also take out the needle valves and put a drop of oil in the seat.


this sucks.

bad 83

iTrader: (3)

Adjusting your floats by the rebuild kit is just a guide. After you rebuild a Nikki, you always recheck the fuel bowl level, then readjust the floats to get the level dead center of the sight glasses. I have never rebuilt one without having to slightly raise or lower one of the floats.

rotary_X7

Hmm well that sucks. ^ I would think the producers of the rebuild kit would make it to where the floats would have to be perfectly adjusted to the FSM. --_--

WELL i have the floats adjusted perfectly and they both wiehgh 12 grams and are not fuel saturated. (tested them)

I ran fuel into it and one float does not float it is sticking. I polished the tangs on the floats, the float pins that sit in the float needle , and also polished the lip inside the float needles seat. SO everything...EVERYTHING is smooth as possible. I think it may be something to do with the float needles springs. I'm going back out to mess with it some more.

Eric

trochoid

iTrader: (6)

The needles tend to bind on the sides as they slide up and down. You should not sand the needles or seats, just lube the sides of the needle and it's shaft with 3 in 1 oil.

rotary_X7

I did put oil in the seat and it slides just as smooth as before. I didn't "sand" anything i used a polishing wheel and some polishing...(lube?) and polished all areas where metal touhes metal on the floats.

I had fuel in the bowls and i blocked the return line with a piece of vacuum hose and a screwdriver. I then ran compressed air into the bowls to see if they would buble up. they did...but i'm not sure if they are floating correctly. I have the floats set perfectly on 16mm up side down...and 51mm right side Up. So everything is to FSM spec.

What do i do..?

It seems as if one of my needle valves aren't sealing correctly...i'm ordering another kit just for the needle valves...

UNLESS someone have spare just layin around??? =P

IanS

iTrader: (4)

Whats your fuel pressure set at or is it stock?

rotary_X7

fuel pressure is at stock. no regulator.