All I have seen or read states red spring for the HIF44.. I have been using a BFY needle and all is good.

 

X2 for the Choke O-ring!!!

As you are not sure of the cam the valve settings in the manual (12 thou i presume) may be too tight. It would not hurt the engine to run it with a wider gap on the valves to see if it may help with the idle issue.

Set the valve clearances per the manual before working on the carb.

Did you check the valve clearances ? If not you are wasting your time setting the carb up it is the last thing to do after points, timing, plugs, valve clearances etc.

Thanks to everyone for your ideas to help me on improving the rough idle with my HIF44 carb. Rechecked all gaskets/seals for leaks and did many adjustments of the screws on the carb. Have been able to get a smooth idle at about 1150 rpm, would like to get it smooth under 1000 rpm but for now this is an improvement.

With more radical cams comes a rougher idle and as you don't know what cam you have it is a guessing game. Higher lift longer duration cams usually require a wider valve clearance sometimes up to 18 thou (stock is 12 thou). Check what your valves are set at and open the gap up two thou then maybe in one thou increments and see if it helps at all.

Thanks to everyone for the suggestions.....this is my first mini so what many of you consider basic suggestions are extremely helpful to me. Have printed all this out so I can have it with me in the garage. Appreciate all the help.........will let you know the outcome.

Although your carb doesn't appear to be new, check which spring is in the dashpot - red or blue. (I have no idea which one you should be using.) The reason I suggest this is that I did buy a new one and installed it. After the trip to the mechanic mentioned did not solve my floodding problem, I discovered that my new-from-Burlen carb actually had both springs in it.

Check for intake system air leaks. Above 1400 rpm they would not be noticeable, but as the throttle closes down the vacuum in the intake increases, sucking on any leak present, leaning out what could be an otherewise OK mixture.

I have the same carb and intake manifold on a 1275 high compression engine.  A Mini mechanic I took it to discovered that there was a casting leak in the alloy inake manifold, which he fixed with JB Weld. I would have missed it. In your photo, it would be right where the drilling for the carb stud near the "SP" in 'Spares' goes deep.

I see also that you have the carb's crankcase vent nipple capped. (The same mechanic also capped mine.) I wonder if the needle selected was intended to be for that system to be connected. Might be worth a try.

 

 

 

The engine is 1380 but not sure of the cam.

Many times the sealing O-ring on the choke mechanism is broken and allowing a massive vacuum leak. removing two flat head screws will allow you to pull it out and check if that's and sealing. You do not have to unwind the spring and all of that in order to remove the mechanism.

As others have said, check your timing and for air leaks first.

I've been using an LM2 O2 sensor and playing with different needle profiles over the past few days with a 1275 that I recently built. I am using this website to help me understand what different needles have to offer in terms of richening the mixture at different points of the profile and comparing it to my O2 readings. I am learning but am not sure what target O2 readings I should really want. But here's what I've found:

1275, stock bore, stock small valve head, stock compression, Kent 266 type cam profile, STage 1 kit, cone filter.

BDK needle, when set for 13's at AFR crusing at 4k rpm using a yellow spring and ATF dashpot oil, I'm wicked rich at idle and and at lower rpms. The jet (mixture screw) has to be dropped way down too, but all of the readings on the fwy are awesome until WOT at over 5K rpm sustained.

I switched to a BBC needle so I could lean it out at idle and it works a lot better around town but below and near 4krpm is rich at 11.5-12.2 AFR but GREAT when over 4krpm and high 12s, low 13s at WOT over 5k rpm under load. The problems with this setup is it spikes lean under throttle lift off to like 14.5-16 AFR depending on if it is momentary like shifting or in traffic and engine braking, or if I'm no throttle going downhill. I tried changing the dashpot oil to 10W40 and it didn't seem to help with the lean or richening under accelleration like I'd expected. 

Anyway, I didn't answer your question-- but my experiences showed me that both needles above, when set to give me ok readings at speed, give me a very lumpy idle due to being over-rich. It's something I've lived with in other setups so I would not risk burning up at high demand, high rpm.  So I'd say that if it is hard for you to set your car for a nice smooth idle at 850-1K rpms, you could be over-rich down there.

And just to be a naysayer-- I've regularly run an 1-3/4" carb on a 11:1 compression 998 with a 274 duration cam on the track and it's awesome. Pulls just fine from low rpms(2K-ish) up to WOT over 6k

Naturally I assumed he had already done the obvious and was looking for more ideas. Hope we get some followup

The only thing you can really tune is the mixture fine adjustment. The adjusting screw is in a recess on the left side of the carb just above of the float overflow pipe in your picture. You might have to lean down on the fender to see it. Turning the screw out leans the mixture and turning it in richens the mixture. Move it in or out until you get the maximum rpm at a given idle screw setting, then reset the idle. Make sure the piston spring is in place and the damper reservoir is full. If this doesn't do anything then there's something else amiss. As Hunter2 implies an uneven idle could be caused by a long duration cam which there's not much you can do about other than change the cam.

my stock 1275 runs fine with 10 degrees static advance, HIF 44.   changed original needle BFY to BCE even better.

look for vacuum leaks as first step ( hoses and gaskets)

What size engine?  What cam? What carb needle?

(I ran a BDK needle in the 10:1 1380 with Swiftune SW5 cam and 1.5:1 roller tip rockers)

HIF44 is almost too much carb for most 1275s and larger depending on compression and cam.

Need help tuning a HIF44 carb on my classic mini. Have installed new plugs, wires, adjusted valves per manual and has electronic distributor. Whenever I set the idle below 1400 rpm the idle is very rough. Would appreciate any suggestions to get a smooth idle under 1000 rpm.