G'day,

I've just fitted a 32/36 Downdraft to my basically stock 948cc Minor. I cannot get it to idle below about 1800rpm. Even with the idle stop screw backed totally off. Even then it's rough as guts. I'm confident I don't have any air leaks.

I can get it to cut out by turning the idle mixture screw in to about 1 1/4 turns. My understanding is that that's about correct as per here:

http://www.racetep.com/webjettune.html

Idle jets are 60 primary and 50 secondary, are these too big for such a small motor?

Help!

i had the same problem when i fitted my webber and it just turned out that the throttle wheel was not letting the butterfly close properly, check that first its easy and free to do

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77 Leyland Clubman
1293cc, LCB extractors, pulsar dizzy (recurved), cooper s disc brakes, 40DCOE Weber

I used to run a Fiat with a similar carb- some of those type Weber carbs have a hidden throttle stop screw on the secondary throttle. make sure it's not far open if at all.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I've checked the throttle stops and they appear to be closing ok. I've also disconnected the throttle cable and allowed it to slacken right off.

There is a reference on a US Datsun site to a blocked "idle air corrector" causing idle at about 2000 rpm, but I can't find reference to it anywhere else, or even a diagram showing me where/what it is. I know about regular air corrector jets, but not about an IDLE air corrector.

I think that they might be little jets into the actual throat, but I'm not sure.

Anybody...?

Is it sooty and rich below 1800rpm, or just it simply stall below that number?

The idle air corrector is a small brass circle pressed in under the float bowl cover, about 1mm in diameter. Not to be confused with the main air correctors which unscrew from close to the accelerator pump squirters. Try blowing down it with compressed air.

Another possibility is that someone has screwed in the idle mixture until it has jammed, which has broken off the pointy end in the carb body. This means the car will not run on the idle circuit?

Also, the idle jet may be too big (screws in the side of the primary barrel). But then it should still idle, it will just puff black smoke and not idle smoothly.

Cheers,

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Brett Nicholson
Greendale (near Ballan) VIC.
1971 Morris Mini Moke
1966 Austin Mini
1965 Morris Mini Traveller
1973 LR Series 3 88
2007 LR Freelander 2

if you have to hold the idle to keep it running check your accelerator pump, the diaphram might be worn out or torn.

sometimes the throttle spindle is worn, letting air thru

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1275

I've got a horrible feeling that the carb base may be warped. I checked (before I fitted it)it with a straight edge, and you can see a fraction of daylight through. I thought it wasn't so bad that the gasket wouldn't correct. MIght need to have it machined...

Cleared all the jets and air correctors, rechecked the idle screw (it's ok) and cannot feel any wear in the spindle. Still the same high idle. The fuel pump is ok too.

The carb I'm using is a 32/36 DGV with a manual choke, I've got a few DGAVs around and a 38DGMS, so I might forget about the choke and have a go with one of them.