Gemini (nikki) Carby Onto A 4k

[Shame_inc]

thanks illl try that

Edited July 29, 2009 by Shame_inc

[archangel62]

Heh..

 

I'm a massive Gemini nut. I have three of them, and an insane amount of parts. To be honest, a lot of Gemini drivers hate the Nikki carb. I mean, everyone hates factory carbys, but specifically, Nikki's often have/develop a massive fuel-cut issue during high G-force (ie, cornering). I'm not sure if this can be ramified by changing the float level, fuel pressure, cleaning or adjusting jets, etc... But the vast majority of Gems running Nikkis will cough and splutter and lose all power whenever you're taking a corner hard. Believe me, this takes a LOT of fun out of driving. Think of how you drift a low-powered car - attack a corner hard, entry however you want, initiate, then punch the gas when the rear tyres are loaded, and the car's at it's grip limit. The Nikki shits itself way before that. You punch the gas, ready for it to power-over, and guess what... Nothing happens... Or you're just going for speed, you come in too hot and the back steps out hard under brakes. You lift off the brakes, countersteer a little, then see the corner's exit. You give it some gas to stabilise the car and power smoothy out. But guess what? Nothing happens, and you're left to keep the car settled and putt out of the corner.

 

Sorry to go on. This is a huge whinge point for me. I've had three Geminis, ran four engines so far, and have spent the last five years trying to get AWAY from the bloody Nikki carby. I've finally whacked a 32/36 on my high-comp G200Z and it instantly fixed the fuel surge issue, and, contrary to popular belief, doesn't chew any more fuel, I still get 10L/100km on average, with a 2lt running ~11.5:1 comp, big Lukey exhaust and mild cam.

 

I did know one guy who never had the fuel surge issue. And one guy who didn't have it quite as bad as me (it got worse when he put a bigger engine in. Hmm.) so perhaps it can be fixed with a proper carby rebuild or professional service. But don't expect to whack one on and go faster. I'd sooner convert my 3K to run biodiesel, or cut a hole in my floor and Flintstone it, than convert to a nikki! But I guess I've had a bit of a raw deal with it.

 

Besides the major fuel-surge issue, though, they're good. Economical, smooth as (when set up correctly, e.g. original purpose), and yes, auto choke. The venturi's are 22/29, so obviously not as big as a 32/36 (which is popular amongst us Gemini addicts) but definitely well sized for K series. I'm not sure if this is the G series head (with it's big ports, crossflow and huge inlet valves :hmm: .... haha sorry, had to) but they also get mad induction noise once the "frying pan" is bypassed.

 

Lastly, if anyone wants one, or bits for one, I have three missing bits or in need of love, come get em, $10 for the lot... Will also accept beer or iced coffee.. :yes:

Edited March 4, 2010 by archangel62

[archangel62]

Oh, and I have a few Gemini workshop manuals, if anyone needs more info on the carby, or tuning info etc, PM me.

[jason12]

I'd also heard that about gemi carbs, but can anyone on here whose put one on a rolla confirm if this still happens? And i might be keen on a gemi carb sometime down the track also..

[Medicine_Man]

Used to run it on my KE70, Never had a drama!

[B.L.Z.BUB]

Bottom line...

 

worth it on a stock 4k?

 

Or wait till extractors etc

[Medicine_Man]

wait till you have extractors..

[B.L.Z.BUB]

SWEEEET ill keep an eye out for a local one.

[Tham]

In Malaysia, the popular modification by the mechanics here is

to replace the Aisan is the stock Hitachi (I think DCH 340) as

used on the Datsun 120Y's A12 and Nissan Sunny 130Y's

E13 engines.

 

The KE70's Aisan is unpopular here as an unreliable and

uneconomical carburettor.

 

The Hitachi gives much improved economy and reliablity

at the expense of some power loss.

 

The Hitachi does have a reputation for some occasional

overflow problems, but a Sunny owner told me there is some

kind of finger-operated release valve inside the throat for that.

 

Nikkis are also prone to flooding, particularly that on the

Datsun 180K of the 1980s. I believe Nikki is a subsidiary of

Hitachi, as can be seen from some design similarities.

[Tham]

In Malaysia, the popular modification by the mechanics here

to replace the Aisan is the stock Hitachi (I think DCH 340) as

used on the Datsun 120Y's A12 and Nissan Sunny 130Y's

E13 engines.

 

The KE70's Aisan is unpopular here as an unreliable and

uneconomical carburettor.

 

The Hitachi gives much improved economy and reliablity

at the expense of some power loss.

 

The Hitachi does have a reputation for some occasional

overflow problems, but a Sunny owner told me there is some

kind of finger-operated release valve inside the throat for that.

 

Nikkis are also prone to flooding, particularly that on the

Datsun 180K of the 1980s. I believe Nikki is a subsidiary of

Hitachi, as can be seen from some design similarities.

[jason12]

I put a gemini carb on my ke55 the other week and noticed a sliiiiiight power increase, and a big increase in induction noise (sick!) Didnt need to use longer studs either, however drilling out the hole for the throttle cable and clamping the right amount of metal (and cable ties :rolls:) proved to be the hardest bit. Havent really noticed a loss in economy either. One thing is I'm unsure if my secondaries are fully working, does anyone know how to check on a gemi carb (I know theyre vacum operated.... is it by that bar thing on the side... if so that keeps coming out and i think the carb may be missing a spring somewhere :D)

[ke70dave]

I put a gemini carb on my ke55 the other week and noticed a sliiiiiight power increase, and a big increase in induction noise (sick!) Didnt need to use longer studs either

 

 

yeah i pretty much found the same thing that you found.

 

i put a nikki on a stocko 4k a few years ago. it sounded great, went fine. but I'm not sure if it actually went any faster. engine seemed to breath better though. but it could all be an illusion from the epic induction noise.

[jason12]

Haha yeah, but for the $25 or so it cost to put on id say its worth it just for the noise :rolls:

[B.L.Z.BUB]

I want one now.

[beerhead]

I definitely got better power with a nikki over the stock carby with a cam, better fuel economy too. The stock jets are a little big though, go raid a mazda 929 and a mazda 323 of there jets that'll give you 6 different fuel jets and emulsion jets to play with inlcuding the ones in the carby already. A day of stuffing around and it'll go purrfect with a bit of patience. I made a tiny bit less power with my Nikki than a webber, but fuel economy went from 13L/100 to just under 10L/100, so it was a good move IMO.