Nikki Modification finally

Engine related articles specific to induction (carby, EFI etc.)
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geminilover3236
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Post by geminilover3236 »

Just looked at your pics again, is your car left hand drive? The throttle cable comes accross the top of the engine
l8nytalumni
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Post by l8nytalumni »

i also installed back the diaphragm for the vacuum. by the way, i just want to know, where does the diaphragm get its vacuum? is it from the carb? or is it from the manifold where the hose is connected to the carb?

i got some pics while i was working. let me know anything you can add. thanks guys!:)


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fuel pump
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i cut the spring to make it short and softer.
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i removed the screw i installed that covers the hole for the vacuum passage to the diaphragm
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geminilover3236
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Post by geminilover3236 »

Looks good.

- The vacuum is gathered from the carby under the secondary butterfly.

- See how you've got your fuel plunger setup to be pushed down. There should be a little 'U' clip to attach to it. You can bend the rod that goes up to that arm so that you get a longer stroke but you shouldn't really need it if you have vacuum secondaries anyway. A stock fuel plunger should do the trick. But, if you do want to use mechanical secondaries and have the fuel plunger giving a little bit more fuel when they open. Take the plunger out completely and take it apart entirely, lift the rubber seal to reveal the other spring and stuff in there. I never really figured it out, just trial and error.

I noticed when I replaced the carby, there was a bit of fuel around the gasket to the intake manifold so I'd replace that when you finish tweaking it so you dont have any air leaks.
l8nytalumni
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Post by l8nytalumni »

geminilover3236 wrote:Looks good.

- The vacuum is gathered from the carby under the secondary butterfly.

- See how you've got your fuel plunger setup to be pushed down. There should be a little 'U' clip to attach to it. You can bend the rod that goes up to that arm so that you get a longer stroke but you shouldn't really need it if you have vacuum secondaries anyway. A stock fuel plunger should do the trick. But, if you do want to use mechanical secondaries and have the fuel plunger giving a little bit more fuel when they open. Take the plunger out completely and take it apart entirely, lift the rubber seal to reveal the other spring and stuff in there. I never really figured it out, just trial and error.

I noticed when I replaced the carby, there was a bit of fuel around the gasket to the intake manifold so I'd replace that when you finish tweaking it so you dont have any air leaks.
i really thought it was the dizzy that causes the stuttering. i'll observe the vacuum first. i might mod the fuel pump as well if i need to.
what gasket did you use to replace the old one?
i also read in the previous thread that you modded the intake manifold. how did it go?
l8nytalumni
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Post by l8nytalumni »

geminilover3236 wrote:Just looked at your pics again, is your car left hand drive? The throttle cable comes accross the top of the engine
yes, it's left hand drive in our country.
geminilover3236
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Post by geminilover3236 »

Yer, dissy can cause stuttering if it is pinging (to much advance) from what I understand. I doubt it would be that if it is stock though.

the intake manifold porting went great, seems to flow a lot better down low with it. Probably could have done a better job with it though. Basically you just want the air to transition smoothly from the carby throats to the intake.

Gasket, I bought some thick gasket paper and cut my own gaskets out as I needed one that was oval shaped instead of the 2 throats.
l8nytalumni
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Post by l8nytalumni »

geminilover3236 wrote:Yer, dissy can cause stuttering if it is pinging (to much advance) from what I understand. I doubt it would be that if it is stock though.

the intake manifold porting went great, seems to flow a lot better down low with it. Probably could have done a better job with it though. Basically you just want the air to transition smoothly from the carby throats to the intake.

Gasket, I bought some thick gasket paper and cut my own gaskets out as I needed one that was oval shaped instead of the 2 throats.
thanks for everything bro. i'll replace the gasket just to make sure and if i have the time and tools i'll mod the intake manifold like what you did. :)
geminilover3236
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Post by geminilover3236 »

No worries dude. Should go sick. Im absolutely loving mine now. Got 500km out of a tank the other day too :D

Cold starts are a bit of an issue. pump the accelerator pump 4 times then hold the revs up at like 2grand for a while till she is good then it's all sweet.

All the best with it.
geminilover3236
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Post by geminilover3236 »

Well, I just can't help myself. Had another fiddle again today with it coz it just didnt feel as good as it did when I had it on my last engine with bigger jets and mechanical secondaries.

So, I ran all around town, seriously, half the day looking for a 1.2mm and 1.8mm drill bit for the main jets. Talked to Motocarb in Nerang and he reckoned that would be pretty much spot on. Schofields in Molendinar/Ashmore ended up being the only place to stock the sizes though I had to settle for 1.85mm which is alright.

Threw them in and altered the idle jets while I was at it running 1.2mm Air bleed and .46mm Fuel.

Took it for a burn, was alright, bit better, idled better too (lumpy cam). Came back and thought I'd do mechanical secondaries again and see the difference. Made quite a noticeable difference, just have to make sure you dont put your foot down till about 2500rpm. So, 4 coils cut off the spring and it still doesnt open fast enough, Hmmm....

I'm just going to run it like this for now and see what my economy is like, stay off secondaries and should be fine I reckon. You can feel it in the pedal where the secondaries start to open anyway.

P.S. Running 80 Primary Emulsion Tube, 70 Secondary Emulsion Tube.
tudorsi
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Post by tudorsi »

I was just wondering is there a specific part number for a Nikki rebuild kit?
geminilover3236
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Post by geminilover3236 »

Not that I know of, I have always just got them to look it up on their systems and order it when I've bought one.
BlueGem
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Post by BlueGem »

There is a part number, it starts with nk but I cant remember the rest because its been 3 years since I worked for autobarn.
AKA Project 64/Stock TE
geminilover3236
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Post by geminilover3236 »

More updates;

So, I was getting fuel surge around sharp left handers or when drifting it in the dry. To fix this problem, I cut the float to 2/3 the original size. taking the meat off the drivers side of the float (opposite the pivot point) and bumped the fuel level up to just above the line, cant go any higher than that or it just starts to flood into the manifold when your parked on a hill.

Hope that helps people out.
Cazz
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Post by Cazz »

Not sure if it's been mentioned before or not, but I STRONGLY recomend a product called "Simple Green" for Carby cleaning. It's purpose built and definitely gave me a better result than petrol/ kero.

From this,

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To this,

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In one afternoon.
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You put you left foot in, You put your right foot in , You take your left foot out and you slide it all about!
l8nytalumni
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Post by l8nytalumni »

just dropping by Gemi. found this link and thinking it might be helpful.
http://www.rx7club.com/showthread.php?t=62678
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