Carby bit

[Pinelli]

HI all,
Currently in the process of ditching the stock carby for my 86 Navara for a falcon weber carby.

I pulled this thing out of the manifold, from underneath the carby. In the picture, it is upside down, the pipes extend down into the manifold. I am assuming that it is meant to help fuel/air flow.
http://proserpnshs.eq.edu.au/home/spine5/carby_bit.jpg
It seems to me that if anything it might actually restrict flow, or allow the fuel/air to flow unevenly to the cylinders (but then, I'm a bit new to carby technology)
So, do I keep it in with the new carby? Any thoughts?

[minisman]

yeah that prick of a thing caused me no end of trouble when i rebuilt my carb.
Why? cos i didnt notice it was removabel and the gasket below it was destroyed. So as a result trying to chase the air leak i pulled my carb on and off 3-4 times (i'm sure you know how hard those friggin nuts are to access)

As for its purpose, I'd say it does aid flow, devices like this often help create better low rev responce.
i definitly wouldnt throw it away, unless the replacement carb advices to. speaking of which did you go for a webber?

[Pinelli]

Yeah, an old Falcon Weber, the 34adm.

If I did it again, I wouldn't necessarily go for the 34adm because the jets are almost impossible to get. I finally found a place in Melbourne that stocked them (I'm in Nth Qld). The weber itslef seems pretty good though. I had to drill out a couple of the bolt holes onteh carby to match the manifold though, but no biggy.

Will be fitting the weber tonight, so news on jetting and driving in the very near future.

(Oh, and yes, I do know now how bloody hard to get those bolts off the nissan carby are. How did they put them on in the first palce? Did the build the carby on the manifold?)

[Pinelli]

Well, this close to success. Revs beautifully, sucks in the air like you wouldnt believe, more power (hate to think about the petrol), but won't idle. I don't mean its rough, it jsut doesn't idle. Pump the pedal a few time before you start, and it'll run for a couple of seconds, but rev it, and then let it drop,and it jsust dies. I'll have to replace the idle solenoid, and I'll have another go at cleaning the primary idle jets. I don't think any fuel at all is going through the idle circuit. Bugger.

So back on goes the stock carby, cause muggins has to drive it to work tomorrow.

[minisman]

I know you cant assume everyone knows everything, so i thought i better ask the stupid question.

Have you played with the idle mixture screw and tried winding the idle screw up a bit?

If you have what is the result? does it idle at something like 2000rpm, but once trying to wind the idle down it just struggles and dies? if so i believe there would be a bockage in idle circuit, or way too small pilot jets.

[Pinelli]

Yep, played with the idle screw. Unfortunately, can't access it while it is on the manifold (d'oh), so it came half off a few times just to adjust it up. Got three different primary idle jets, including the original Falcon .070.

And no go. No idle at all. The idle solenoid is dodgy, so I'm going to replace that, give the idel circuit a really good clean, and off we go again.

BTW, feel free to ask stupid questions. If I thought I was smart enough to know everything, I wouldn't be posting here :) If there's anything else obvious I might have forgotten then fire away, I won't be offended.

[Tree cutter]

The main jets and air corrector jets are the same as DGAV weber jets so they shouldnt be too hard to find. The primary idle jets could be hard to find. Nardek make new idle solenoids as well as floats and gasket kits if you need them. You might need to put a fuel pressure regulator on so you can drop your fuel pressure to 2.5 PSI so it doesnt flood when you are going over a lot of bumps. Webers need lower fuel pressure than jap carbs because of their short wide floats.

[HiFiRobbie]

If the idle solenoid is dodgey, you've go no chance.

Without that powered up, you will have NO idle circuit. It just needs 12v whenever the ignition is on. Then when you switch the ignition off, it shuts off the idle circuit so there is no run-on. You should hear it click whenever you switch the ignition on or off.

Let us know how you go!