And in a startling turn of events the carb has been refurbished.
The rebuild kit seems to cover several variants as I have plenty of parts left over.
Most of these excess items bear no resemblance to any part I have removed from the carb in the process or form part of the carb as it was as I took it off the car.
Not only have parts been renewed, a full clean up of all surfaces (inside & out) has happened.
I might even buff up the outside with some polish and a buffing wheel.

DanClarke said:

And in a startling turn of events the carb has been refurbished.
The rebuild kit seems to cover several variants as I have plenty of parts left over.
Most of these excess items bear no resemblance to any part I have removed from the carb in the process or form part of the carb as it was as I took it off the car.
Not only have parts been renewed, a full clean up of all surfaces (inside & out) has happened.
I might even buff up the outside with some polish and a buffing wheel.

View attachment 334584

Click to expand...

Lovely job, well done.


($64,000 question. Did the kit include a new jet? )

Anyway. Let's hope that putting it all back on with new gaskets and the nuts tightened up properly you get a much smoother tick-over. And, by some miracle, the smell of petrol has gone!

DanClarke said:

And in a startling turn of events the carb has been refurbished.
The rebuild kit seems to cover several variants as I have plenty of parts left over.
Most of these excess items bear no resemblance to any part I have removed from the carb in the process or form part of the carb as it was as I took it off the car.
Not only have parts been renewed, a full clean up of all surfaces (inside & out) has happened.
I might even buff up the outside with some polish and a buffing wheel.

View attachment 334584

Click to expand...

Have you got a straight edge you can test the flatness of that flange with, and the flange on the manifold? Nuts need to be tight, but not monkey tight, or the aluminium can distort. ( but you know that)

freelance said:

Have you got a straight edge you can test the flatness of that flange with, and the flange on the manifold? Nuts need to be tight, but not monkey tight, or the aluminium can distort. ( but you know that)

Click to expand...

The last person to touch the engine didn't

Stanleysteamer said:

Lovely job, well done.


($64,000 question. Did the kit include a new jet? )

Anyway. Let's hope that putting it all back on with new gaskets and the nuts tightened up properly you get a much smoother tick-over. And, by some miracle, the smell of petrol has gone!

Click to expand...

Kit indeed did have a new jet tube. , the needle in the carb is a "BBA" (not sure that is right for this engine?).
Strangely the needle holder was sticking about 3mm proud of the bottom of the piston, and that certainly is not right, but that may have been me not doing it up tightly enough. I didn't see much more amiss. No scoring or dent/dinks anywhere.
Butterfly shaft was badly corroded and all the seals everywhere were hard and perished. I have just noticed (shining a torch into the carb chamber that there is a glimmer of light on one side of the butterfly but not on the other. Noe I have splayed the securing screws I probably cannot shift it.

DanClarke said:

Kit indeed did have a new jet tube. , the needle in the carb is a "BBA" (not sure that is right for this engine?).
Strangely the needle holder was sticking about 3mm proud of the bottom of the piston, and that certainly is not right, but that may have been me not doing it up tightly enough. I didn't see much more amiss. No scoring or dent/dinks anywhere.
Butterfly shaft was badly corroded and all the seals everywhere were hard and perished. I have just noticed (shining a torch into the carb chamber that there is a glimmer of light on one side of the butterfly but not on the other. Noe I have splayed the securing screws I probably cannot shift it.

Click to expand...

Thank the lord for the new jet tube! Brill!
As you know the needle must be seated so its shoulder is flush with the underside of the piston. Now you have found this, putting it right will be yet another step closer to getting your engine back to "normal".
If there is a glimmer of light, as long as it opens fully and closes fully, trying to get rid of it by removing the screws may simply shift the glimmer elsewhere. I'd need to see what you mean by a glimmer on one side but not on the other. Do you mean one end of the spindle but not on the other? Or on say the manifold side but not the filter side? Or vice versa?
TBH I wouldn't worry about this at all.
The BBA needle, as you know, is not standard for this engine, it is for "modified 1300s with single carbs and 276 cam or similar". According to the information you got back from the previous owner the only mod is increased compression ratio. Now the MG Metro engine already has 1:10 compression, so increasing it may have a slight beneficial effect, but there is no need to change the carburation at all if that is the only change that has been made. It makes me wonder why it has been changed.
"Whilst most of the engines do not really give a whole lot of difference in performance, the one outstanding version is the MG Metro engine. Where the majority of the variously similar power plants put out around 63-65bhp, the MG metro achieves a more spirited 70-74bhp. This is due to a higher compression ratio (10 -1), larger inlet valve (35.7mm instead of 33.3mm), and - mainly - a more sporty camshaft with half-decent induction and exhaust systems. The inlet manifold being a reasonably good flowing, water heated aluminium example. Rover finally got the hint having witnessed the prolific after-market fitment or such an item to Minis in epic proportions for years. The exhaust manifold is a cast iron 'LCB' style with a pair of exhaust downpipes instead of the more common single item and works very efficiently. A bonus of this over the more common after-market steel-tubed LCBs is that it is much quieter by dint of absorbing more exhaust 'noise'. Coupled to a pair of Maniflow tubular steel downpipes it is very nearly as efficient as a full tubular steel manifold. The cylinder head is more along the lines of the old Cooper S spec and in fact flows slightly more air than it's predecessor, the camshaft being the sportiest fitted to any production A-series engine. It uses the inlet profile and timing of the original 997 Cooper cam and the exhaust specification of the old Leyland Special Tuning '731' fast road cam. " From Keith Calver the Mini guru.

You could do worse than go back to the BDL. Again, back to the baseline. It is deffo what I would do if you still have issues.
Best of luck mate!

It has just struck me
Did I remember correctly that you said that when you looked in the carb the jet was way down low?
And now you have found that the needle was sticking too far out of the piston?

That kinda matches, but would lead to poor vaporisation. and then an increase in fule consumption. I am wondering if it was done in some way to try and compensate for having the wrong needle in there. Or if simply the needle had dropped, he didn't notice except that he noticed it was running lean, so tried to compensate, as you would if you didn't look at the needle, by dropping the jet.

All good fun!!

you may have it already and did the kit come with new phosphorous bronze bushes and seals for the throttle shaft

mystery said:

you may have it already and did the kit come with new phosphorous bronze bushes and seals for the throttle shaft

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Superb guide!

I have never seen a rebuild kit with phosphor-bronze bushes. I have heard of some other ways of reducing play at that point which I am sure you will agree, tends to be the biggest source of leaks.
But if Dan wants to re-bush it, here is a "little" guide!


@DanClarke, if your butterfly really is wrongly positioned, it isn't the end of the world, you can saw the splayed ends of the screws off and once properly positioned, use Loctite to lock (the rest of!) them in position, (see Vizard) but I personally would rather get new screws or push the splayed ends together a tiny bit so that the screws can be undone a tad, reposition the butterfly then tighten them, maybe with a drop of Loctite on, then re-splay the ends again.

All good fun!!

mystery said:

you may have it already and did the kit come with new phosphorous bronze bushes and seals for the throttle shaft

Click to expand...

Sadly the kit came with no bushes, but luckily, I could not feel any slop in the shaft at either end. NEW seals were provided.

Minor Update:
The carb is back in the car.
OMG what a struggle!! There is no "Porthole" in the bulkhead as is often seen on minis so there was virtually no "wiggle room".
I had to remove the new air cleaner I had just fitted to the carb in order to get the clearance to guide the carb baseplate over the manifold studs. Then it got worse. 3 nuts span on no trouble at all. The 4th (trapped behind throttle & choke actuators just refused point blank. 1 hour was spent trying to get the nut to start..... Nope. Nuts were swapped, still nope!
Took the whole carb back off and tried all 4 nuts on this stud. No problems.
Put it back on the studs and got all 4 nuts to spin on 1st time. Go figure!!! Grrrrrrrrr.
Next up... try to attach the air cleaner again, will it fit?
Only just, but it is not only ON it is all done up nice and tight and the crap mock M6 Acorn nut and star washer has been changed for a Stainless Steel Nyloc.
All the fuel side plumbing is back on too but I have called it a day. There is only so much time an old man can spend bending over a Mini engine with his arms outstretched using his arthritic hands as both eyes & spanners to operate things he cannot see.
If it isn't raining tomorrow I will connect the accelerator and choke cables and see if it bursts into flames life when I try to start it up. Thanks for all the advice & encouragement, it is much appreciated.
A fancy Innova timing light is on its was from Amazon (USA) and will be here on the 10th I think.

DanClarke said:

Sadly the kit came with no bushes, but luckily, I could not feel any slop in the shaft at either end. NEW seals were provided.

Click to expand...

Good thing you didn't need them then! I don't think I have ever come across an old SU that didn't have play there.
But I am very pleased that your seals are not second-hand!!!

DanClarke said:

Minor Update:
The carb is back in the car.
OMG what a struggle!! There is no "Porthole" in the bulkhead as is often seen on minis so there was virtually no "wiggle room".
I had to remove the new air cleaner I had just fitted to the carb in order to get the clearance to guide the carb baseplate over the manifold studs. Then it got worse. 3 nuts span on no trouble at all. The 4th (trapped behind throttle & choke actuators just refused point blank. 1 hour was spent trying to get the nut to start..... Nope. Nuts were swapped, still nope!
Took the whole carb back off and tried all 4 nuts on this stud. No problems.
Put it back on the studs and got all 4 nuts to spin on 1st time. Go figure!!! Grrrrrrrrr.
Next up... try to attach the air cleaner again, will it fit?
Only just, but it is not only ON it is all done up nice and tight and the crap mock M6 Acorn nut and star washer has been changed for a Stainless Steel Nyloc.
All the fuel side plumbing is back on too but I have called it a day. There is only so much time an old man can spend bending over a Mini engine with his arms outstretched using his arthritic hands as both eyes & spanners to operate things he cannot see.
If it isn't raining tomorrow I will connect the accelerator and choke cables and see if it bursts into flames life when I try to start it up. Thanks for all the advice & encouragement, it is much appreciated.
A fancy Innova timing light is on its was from Amazon (USA) and will be here on the 10th I think.

Click to expand...

Minis were my first cars, and I was grateful at the time for having slim hands! Notorious for being tight under the bonnet, and elsewhere. You are learning with every move you make, what needs to be put on in bits and what can be put on all made up. air filter and holder deffo has to be put on at the end . Funny that I didn't know any different and thought this was normal! Of course with front wheel drive/ transverse engines having become the norm, it now is!
By the time I did the last one, my hands were no longer slim, but I somehow seemed to remember what was possible and what was not. On the last job what shocked me was the torque to which the front hub nuts had to be done up. I even bought a special powerful torque wrench that I have never used on anything else since! Somehow I avoided ever having to do this all those years ago.
Those acorn nuts are total pants. They look sort of nice, but that is it.
You'll get there in the end. softly softly, catchee monkey!

I only have a small and insignificant update (something my wife often complains about).
Throttle & Choke cables were attached (in the rain).
Car starts OK, no identifiable petrol leaks or overflows, so the basics must be OK.
I did get the idle revs to sit at 1,000 with no hunting up and down, but that does not mean very much.
I will opt to wait for the arrival of the proper timing light/rev counter to allow me to set both static timing and to gauge the max advance and look at the advance curve. No rush, the car is not needed as a daily driver.

DanClarke said:

I only have a small and insignificant update (something my wife often complains about).
Throttle & Choke cables were attached (in the rain).
Car starts OK, no identifiable petrol leaks or overflows, so the basics must be OK.
I did get the idle revs to sit at 1,000 with no hunting up and down, but that does not mean very much.
I will opt to wait for the arrival of the proper timing light/rev counter to allow me to set both static timing and to gauge the max advance and look at the advance curve. No rush, the car is not needed as a daily driver.

Click to expand...

Well done for the progress.
Has the pong of petrol improved?

Stanleysteamer said:

Well done for the progress.
Has the pong of petrol improved?

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Well, it isn't as bad, but still a lingering odour. I wonder if the pump plumbing is leaking. It is on the bulkhead side of the engine.

DanClarke said:

Well, it isn't as bad, but still a lingering odour. I wonder if the pump plumbing is leaking. It is on the bulkhead side of the engine.

Click to expand...

Although it isn't easy to get at, and TBH would be easier with the carb etc removed, there isn't that much to check. so you should get to the bottom of it quite quickly.
I'd check to see the spacer hasn't deteriorated.
If it has, a replacement should be easy to get hold of.
If you have no spacer, then a new gasket seems likely.
If the leak isn't to do with the pump then...
Well you know where to look.

Stanleysteamer said:

Although it isn't easy to get at, and TBH would be easier with the carb etc removed, there isn't that much to check. so you should get to the bottom of it quite quickly.
I'd check to see the spacer hasn't deteriorated.
If it has, a replacement should be easy to get hold of.
If you have no spacer, then a new gasket seems likely.
If the leak isn't to do with the pump then...
Well you know where to look.

Click to expand...

I bet it is weeping from the in/out of the pump but evaporating (with stink) before it hits the ground.

DanClarke said:

I bet it is weeping from the in/out of the pump but evaporating (with stink) before it hits the ground.

Click to expand...

so just a slightly split pipe or a jubbly clip needs tightening. Both easy fixes.
I have to admit that after your last bit of work I'd have taken it out and ragged it a bit.
You have great self-control.

I remember when I worked as a brickie back in the 80's, I had a Clubman estate (shed) it was a wreck with an MOT.
It used as much oil as it did petrol, the back doors were so rotten, I used a piece of timber to stop my tools falling out...it was bad.
Anyway, I was driving home, up the M40 when it suddenly died, there was a stink of petrol and lots of smoke.
When I checked, the fuel pipe had come off the carb and dumped fuel over the hot engine, that was the smoke.