17 replies to this topic

[mellon87]

I have twin hs2's in my 1275gt although it has a 1300 metro engine in it now.

 

Can anyone tell me if H6 needles are sufficient for this engine as it is running pretty rich and the mixture is not easy to get right at all. Ive used colortune and the lifting pin method but no joy.

 

I have just removed the carbs, cleaned them up and about to refit from scratch but thought I'd look into changing the needles before I bother going through the whole setup again.

 

From the description below it appears that the H6 needle is not correct or am I missing something? Please help.

 

Mini Cooper S Mk III, 1275 cc, (12H) 1969 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Twin SU HS2
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AH2
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EB
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 rpm

 

Cheers, Ross
 

 

 

 

[carbon]

Ross,

 

H6 needles are quite a bit richer just off idle as compared to the M's, which are quite rich in the first place. When the Cooper S came out fuel consumption was not such an issue..

 

You don't say what the spec of your motor or what springs you are using, but I think you will struggle to get these H6 needles to work.

[KernowCooper]

If its a standard metro engine then the head/cam/CR will be different than the 1275 S settings for the HS2s, bit more info on the engine and then we can advise a better starting point

[mellon87]

Sorry guys.

 

 

Source Vehicle :  Metro  Engine type & CC :  A+ 1275 cc Transverse mounted  Fueling :    Engine features :  A10 emissions 95 Ron Unleaded petrol Pre-engaged starter Wide Ratio Rod Change gearbox with Pot Joints Breakerless (electronic) ignition Gearbox features :  Std. Ratio Rod Change gearbox with Pot Joints  3.4:1 Final Drive 

 

 

It also has a kent cam (fitted by previous owner) but I don't think anything else. Also, the above suggests its electronic ignition but it is not.

 

If you need more info please let me know..

 

Thanks, Ross

[mellon87]

Also, Red springs. Thanks.

[KernowCooper]

Its a unknown cam ? no mention of if its got a modified head as far as you know ? its going to be a try m needles and see what its like on road but they would be a starting point. When you say running rich is this just a cruse or flat out under power? Have you got access to a CO Meter ? If so set the idle at 3% and see what its like from there, if not do the lifting pins, ensure they are balanced first though.

[mellon87]

Cheers Kernow.

 

No I don't have access to a CO2 meter unfortunately.

 

It was running rich even idling (black smoke) and altering the mixture did not seem to change it much at all. Im not sure why the H6 needles would have been used in the first place..

 

No I don't believe the head has been altered but the cam is a kent 276.

 

Ill try the M needles, I have a balancing kit so this shouldn't be an issue.

 

Thanks

[carbon]

Before getting the M needles try putting a pair of blue springs in place of the reds.

 

The H6 needle was used on twin HS2s in the AH Sprite 1275, but only with blue springs not reds.

[mellon87]

So would you say there is little difference in the h6 and M needles if it is just the springs that may need changed?

 

Ive compared them on a website I found and there was very little difference between them.

 

Im all new carbs, its a lot to take in and amazing how difficult they can be!

 

cheers

[KernowCooper]

If you have a 276 Kent and the head is a standard metro head then the cam will not be able to do much in the way of a performance upgrade, you need to be getting the head done to match and improve airflow. Have you checked the float levels in the HS2s?

[A-Cell]

Blue springs. Then if still too rich, GY needles.
Check the plug colours after a run.

[mellon87]

Float levels are ok, around 4mm as per manual.

 

I noticed before I stripped them that one of the jets would not screw up flush with the bridge therefore it would always be running rich (I presume) so maybe this will make a difference after refitting. But I wanted to make sure the needles etc were suited to the engine before I bothered doing it all again and wasting time.

 

As I said, im new to this, setting them up will probably take me a whole day and with a one year old, wife, full time job etc etc this will no doubt roll into a whole weekend so didn't want to waste time.

 

Ill try blue springs first, then see what it sets up like.

 

Also, what kind of mods to the head would you expect to see and how would I go about checking that these have or havent been done?

 

Cheers

 

Ross

[KernowCooper]

If its a unknown head then a look in the ports for opening out / flowing and valve sizes but difficult to do with the head in place

[Spitz]

 

From the description below it appears that the H6 needle is not correct or am I missing something? Please help.

 

Mini Cooper S Mk III, 1275 cc, (12H) 1969 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Twin SU HS2
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AH2
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EB
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 rpm

 

Cheers, Ross
 

 

 

 

I don't have it with me......but I thought the Haynes listed "M" as the rich needle.
Also....I find it odd that the above states " MKIII, 1969 on...... the MkII S was produced until 1970 ( Jan )

[petehuws]

I use GY needles in my twin hs2 with blue springs and the fuelling is spot on for me