DiscoQuinn

Seems the motor chugs on hard corners when racing. Stripped stock 12a, stripped down Nikki. Unknown nikki mods, but continues to chug and try to die. Seems to be that the bowl is empty after a few laps. Even providing more fuel with multiple different fuel pump setups has not solved the problem.

I've come to the conclusion that there is either a problem with the float jamming on hard corners, allowing the engine to empty the float bowls, or the gravity of the turn forcing the fuel out of the carb out the jets, flooding temporarily, then running lean once the bowls are empty.

Eitherway, this needs to be solved.

I have a 13B 6 port Holley intake but that obviously won't fit. Should I look to trade, what setup should I hunt for? I drift my little wagon hard!

flight_of_pain

Do you still have the tiny screens on the banjo bolts for the "y" pipe that feeds the float bowls? I have had nothing but trouble with those things.

In my personal opinion... you may want to go EFI, an MS1 megasquirt is only about $200 these days.

Isaac

Directfreak

iTrader: (2)

^ This.

cfamilyfix

iTrader: (15)

yeah I'm no expert on this, but a steady 40psi at a computer controlled pulse will def eliminate this problem, since the nikki runs on like 2.5 to 3lbs and has relatively small bowls (pun intended). I like you wagon...any video's?

DiscoQuinn

http://www.youtube.com/watch?v=sb8jL8Gmq0U

DiscoQuinn

EFI isn't an option at this point.

Weber 32/36? Holley? Sterling? Suggestions beyond EFI?

PK_12A

iTrader: (3)

I'm running an RB Holley w/ intake and center hung bowls and like it alot haven't went sliding with it but, it runs and drives great and I get on it pretty hard from time to time in the corners.

nff

no expert but i'd say a dellorto or a webber would likely be better holley's are known for draining under g loads also.

Kentetsu

Is this happening primarily on left hand corners? If so, try reducing your fuel pressure until it goes away.

On a hard left, fuel can "slosh" into the barrels of the carb, causing it to flood out. I solved the issue (observed during autocrosses) by using the method above.


.

Redliner223

iTrader: (6)

You trying to kill it?
That was a pretty high speed for a turn, might want to lower her a bit so she's not flying around.
Sorry, aside of the original topic.

DiscoQuinn

It was mostly from left hand corners. Good observation. I had my fuel pressure regulator fully open in an attempt to give moe fuel, but perhaps less was the answer all along.


For a brief moment I had given the car away, the temporary owner sought to solve the problem with a pile of fuel pressure and I'm worried they may have damaged something in the carb, as they were feeding it with two pumps and a pressure regulator after the return line.

flight_of_pain

Once you dial down the fuel pressure, re-check the float heights.


Isaac

rrob311

+1 on the float level. I've had the float off a hair and it caused a myriad of problems.

RotaryEvolution

iTrader: (30)

usually it's a flooding issue on hard cornering and not a starvation issue. try lowering the float height a tad to just under the dimples on the sight glasses on the sides of the carb.

you do not need to fully disassemble the carb or even remove it from the car to adjust the height of the floats. just take off the hat stud bolt and the phillips around the perimeter and pop the top off the carb which will have the float assemblies in it, readjust the height down a little and retry. 15 minute job. and lower the fuel pressure back to normal.

just be careful not to drop anything down the carb throats while working on the carb, don't rush it.

DiscoQuinn

I'll give it a try. I'm worried the temp owners damaged the carb as it no longer starts. Have to pull it all apart, check the plugs etc etc and go from there.

Thank you for all the great information!



Note: Should the regulator be before the on the feed line, or after on the return?

orion84gsl

iTrader: (5)

On the supply line before the carb. Spend some bucks on a reliable ACCURATE gauge. One with a 10psi range. RE-Speed sells one for about $60. Worth it.

DiscoQuinn

Picked up the car last night. Showed up to tackle an impossible battle, but instead the car fired up on the first crank. I enjoy 12a's. will need to do some organizing of ths fuel system. Then I'll update with results. Thanks guys.

Redline-RX3

iTrader: (5)

If you don't get it sorted start looking for a Weber 48IDA set-up.....great throttle response and very tuneable.

Kentetsu

Seriously, don't start messing with floats and stuff, just find a parking lot and use it like a skid pad. Reduce the pressure in small steps until you no longer have the issue, and you're all set.

I lost no performance in any way by reducing the pressure, and gained in the fact that it ended the left handed bog-n-smoke show.

DiscoQuinn

Smoke eh? I get no smoke just erratic power surging. I went to pick the car up thinking it was a complete mess and fired up on the first try and drove it home.

I'll be running the fuel regulator on the feed into the carb, set very low for the next track day. I live on an island, beside a police station. No where to hide and do testing sadly except the track.

Kentetsu

Not a lot of smoke, just a bit as the motor recovered from the excess fuel. It would usually clear up within a few seconds of getting out of the turn, but in autocross you're already to the next apex by then.

It was a bit frustrating until I watched a video and figured out that it was excess fuel, and not starvation, that I was dealing with. Sterling helped me figure out the cause, but I went a different route to the solution (he recommended finding old RX3 type floats). My own way was a lot easier, and I didn't lose performance anywhere (still plenty of pressure to feed the Sterling carb). Just an end to the lefty boggy problem.

Good luck. Hopefully you can solve this just as easily as I did.

P.S. Pressure guage should be installed between regulator and carb to get accurate readings (I still need to correct this on my car). And the only guage that will give anywhere near accurate or trustworthy readings is the one from www.re-speed.com Don't waste money on anything else, because it will be so inaccurate at the low pressures we deal with that the readings would only mislead you with their inconsistency...

80's old school

iTrader: (7)

I had the same problem and it is solved....PERIOD!!

1. Go to autozone and get two RX-3 floats. Sorenson brand.
2. Install and set float lets (or assure float levels) in the middle.
3. Use 2.5 ish psi of fuel pressure.
4. Race the **** out of it and enjoy!!!

DiscoQuinn

I work at a parts store and can't seem to find these floats!

Finally got out to the track yesterday, besides my linkage exploding and goign full throttle on the first corner, the flooding has gotten very bad!

Glazedham42

iTrader: (4)

Did you find both of the Rx-3 floats, or are you using two of the same side floats in the carb? I've got two Rx-3 floats that I bought from Autozone a while back, but they are both the same. Both rights, or both lefts. I can't remember which, but I couldn't find a pair of them so I just bought two of the same side. I wasn't able to find a matching pair ever. I've heard that you can use either float in either side and it still works fine. So I was goign to use my two identical Rx-3 floats in the carb and see what happens.

Just wondered what you did. Also, any tips you can give me on setting up these Rx-3 floats out of the box would be MUCH appreciated. I'm not exactly sure how to set them correctly when I install them in the carb for the first time.

Thx,
Jamie

DiscoQuinn

Yes, more info on these floats. Part numbers would be dope. I work at big parts store here in Canada and can't seem to find any floats for them. I found a catalog that had nikki's listed, but not specifically for the RX3. Plus there was only one part number for all the Nikkis and the part number was the same for each.


edit, I had the pressure cranked down and still had the corner flooding issue. Seems to be an issue with the carb, not specifically the pressure.