weber carb needs choke to run

[beermanpete]

If the float is plastic it can absorb fuel slowly and get heavier but still float. This will change the realized fuel level, raising it and causing a rich conditon without having the classic sunk float fuel leak. Perhaps you could compare the two floats by weighing them or simply swap them in the carbs to see if the problem follows the float.

[2sixTZombii]

I was suspecting the float too, so I actually swapped fhe entire top half float included from one carb to the other and it didn't follow the top. I wondef if we cracked something the first we reinstalled the air corrector jets, and just didn't realize it. I half considered just buying a set of used SUs and rebuilding them, but looking at the SU is confusing enough without even touching them, le rebuilding them, it doesn't even look like a carburetor, I just don't have the confidence that I could work on a set of SUs, where as the webers are painfully simple. Although I am failing at fixing this one so........

[beermanpete]

In your first post you said, "I can actually see fuel coming out on this one." Where, exactly, is the fuel coming from?

[2sixTZombii]

In your first post you said, "I can actually see fuel coming out on this one." Where, exactly, is the fuel coming from?

When you open the choke all the way for the 5-10 seconds it stays running, you can see a steady drip from the "auxiliary venturi" this thing

http://atspeedracing.co.uk/products/images/71115_1.jpg

[2sixTZombii]

Come to think of it, if this thing was cracked and thats thats why it drips fuel could that be my issue? Something new to check tomorrow.

Edited April 3, 2014 by 2sixTZombii

[beermanpete]

Fuel dripping from the aux. venturi suggests high fuel level in the float bowl. The fuel level is normally very close to the level of the discharge port in the venturi. When the fuel level is a tiny bit higher than the discharge port it will drip out. Low the fuel level a little bit and see what happens.

[2sixTZombii]

I'll reset the float tomorrow and see what happens. Possibly found a good set of polished SUs to just replace these. I hafe to lose to a couple weber DGVs but I hear SUs are far better anyways.

Edited April 3, 2014 by 2sixTZombii

[beermanpete]

The SU is better? Possibly. Proper set up and adjustment is very important and the SU has the home court advantage. I had a 260Z with DGVs and it ran fine and (using the butt dyno) made similar power compared to my 240Z with SUs with either a 240 or a 280 engine. From my measurements the DGV is has the same total area at the throttle valve bores as the SU so the total air flow is propably similar. The down draft configuration does require an elbow in the intake but on an otherwise stock engine I doubt it is the performance penalty that some people suggest it is.

[2sixTZombii]

I figured it wasn't a big difference with stock internals, and I know DGVs are great carbs. I plan to do some performance mods later down the line, but if the webers held me back I could improve them later down the line. I am considering getting a different weber and rejetting it, but getting a set of SUs that are a straight bolt on and fly set up is looking rather attractive. I could a set with intake, and clean balance tube for 300.

Edited April 3, 2014 by 2sixTZombii

[2sixTZombii]

Well she runs pretty great now, I still run webers but I scored a different pair off a guy on datsun classifieds, for 120 shipped. And shd runs good with no choke, a nasty bog when you punch it, but I think I can jet alot of this out, these carbs run smaller jets than my old ones so I might do some swapping.