nikki carby tweaking.

[rob_w]

im not entirely sure if this is good enough for r+d, but you can improve your nikki as follows.
you will need:
2 nikki carbies, or 1 set of g200 jets, pliers, flathead screwdriver and some sort of silicone seal.

unscrew and remove vacuum secondary diaphragm retaining plate.
with end cutters/tinsips/pliers, reduce the size of the diaphragm spring to 1/3 of its original size, then re-assemble/seal.

then, remove the top of the carby and install g200 jets. if jets are unavailable, remove the primary circuit jets with the chrome plated ones from a donor nikki, then,re-assemble and seal.

tune as normal, but watch your economy die a little for the sake of grunt. [with the chrome jets].

the difference is not as great as a 32/36, but if you have an hour and some spare carbies, its a great way to improve those burnouts.

i have recently done the g200 jets version, [having done both in the past], and can honestly say that it does make a small but noticable difference.

hope this helps someone, [and dont get me flamed],
rob.

[Gene FJ20DET]

if u wired up the mechanical 2ndarys it will be just as good if not beter than a 32/36
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[rob_w]

i found that it is difficult at best to convert the secondaries from vac to mech, if not nigh-on impossible.

discarding these facts, how can you say a 22mm primary with a 28mm vac or converted mech secondary can flow as good as a 32 primary and 36mm mech secondary? remember, at the end of the day, 22mm is still 22mm, and remember that the WRC cars run a 34 mm restrictor, that caps their output at about 300 bhp, from the possible 500+ they could produce.
such is the effect of a restrictive inlet system.

besides, with the mods mentioned in the original post, you dont really need to change the secondaries, as they kick in when needed. do it and see for yourself, but i fell that if you want mech secondaries, for all the hassels involved, get a weber.

but if you figure a way to rig the secondaries to be mechanical, by all means, share in detail.

cheers,
rob.

[Gene FJ20DET]

my bro does it to gems all the time. all u need is a piece of wire
i will ask hom how
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[rob_w]

i tried filling the little slotted bit on the throttle cable attachment, but all it managed to do was make the throttle stick wide open.

remember to explain the wiring in detail,
thanks,
rob.

[PUNK]

It is piss easy to wire the secondaries in. Have'nt done it in a while. But from memory as the other guy says all you need is bit of wire. You just wire the throttle to the secondary linkage. You can adjust where it will cut in by the length of the wire. YOu could set it to come on at about 1500rpm and you then have two barrels feeding fuel right through the rev range rather than just when you boot it hard.

[Gene FJ20DET]

from memory thats exactly it
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[Gold TX Sleeper]

On my Niki there is an actuator arm that protrudes through the accelorator cable bracket. It seemed to me like it was some sort of mechanical over-ride for the seconday's at a certain throttle opening - about 2/3's. After chatting to a mechanic he confirmed my theory.
I simply found an old bolt that perfectly fits through the accelorator bracket and retained it in place with the two nuts, ( i found by having 1 nut attatched sometimes it came undone thru vibrations, so having one extra fitted after it stops it from unthreading itself). Now my secondary's come on sooner when the bolt hits the actuator - around half throttle is needed for the secondary's to open now. I fiddled with different sized nuts and bolts to get the secondary's to open at different stages. The set-up i have now is ideal for my driving and retains good economy. It's most noticeable on the highway at 100k/ph, as at this speed and throttle opening the bolt is juuuuust resting on the actuator arm. All i need to do is lightly squeeze the accelorator and the car takes off like it's just come on cam.
As a side note, i used to always race a 2L MKII Escort on the highway, we would sit along side each other at approx. 100 K an hour and toy with each other. After i did this mod i found i could pull away from him alot quicker. I also retain my economy, as around town with normal throttle applications the bolt doesn't hit the actuator arm. So you could say i kinda have the best of both worlds with this simple and free mod.
Cheers,
Jasyn...

[EVLJT]

you can weld the rods together and it works fine, have done it to every gem I have owned over the years.

[rob_w]

OK, from all your help, i have figured it out, and it works fine.

what i did was get some old speaker wire, [any insulated type should work, as long as its strong, smooth and flexible], tie a small loop in it at one end, hook this end to the secondary butterfly lever, [small flat rod that rests against the 'mech override', has spring underneath it..], then looped it down between the two rods, and wrapped it round the primary throttle linkage [where cable goes]. this means that the cable pulls open the throttle at the desired throttle position, i have mine at just over 1/2 throttle, but you could set it up like an IDA weber..].
there is no noticable loss in economy with current setup.
phew. thats it i think.

hope this helps someone.
rob.

[MrSHADOW]

I got all inspired after reading your posts, so I went and did it to the GF's Gem, I used Zippy ties, 4 I think, and i basically tied them in a manner that doesn't allow the arm from the secondary to slide very far before being forcefully opened by the primary(mechanical override as some call it). Hope that helps all the backyard performance peoples.

[Gene FJ20DET]

LOL!!!!! "centerlink performance"
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