Poor Running ?

As I've only recently bought the car I had a quick look through some of the receipts to see if they might shed some light.
It seems that a company that is well known to zeds tuned the engine just less then 3 wks ago :confused:

Still, I take it the inlet manifold is deffo linked between the 2 carbs?
Does anyone know if fully closing the large air screw isolates each carb/ bank ?
 
you may have the bill, what was said about the running? perhaps a phone call to the company may shed some light....
 
Eventually got out today for another fiddle
Went for a blast but still the same so decided to take a closer look into the carbs.
Double checked the float bowls for crud then went on to remove the dash pots just to have a look n reverse blow down the jets. Everything seemed ok until I looked at the 2nd carb n found its needle to be a little wonky lol

Short Video

What would a bent needle like that cause?
I noticed with the needles removed and whilst looking down into the carb the jet/holder assem has sideways movement when wiggled from underneath, is that correct?

Short Video
 
oops that aint right, you would get very poor running. new needle needed. as for the seat...oh dear.........

Strip both carbs down to ensure no parts have been left out including the sealing rings.The outer ring should be a press fit and no slop.
 
I think the jet goes down for the choke it lets more petrol get past, but that bent needle isn't going to be doing any good so I advise you to buy a new pair coz the straight one might be worn & you might not get an exact copy.
 
I've got some technical description and setup info on various SUs.

I'll sort it out tomorrow and PM you to organise the best way of getting it to you (post, fax, scan).

Do you have a metal tab on the carbs with any numbers on? Mine were off a 2.2 Rover TC, 1966 and still do a grand job.
 
Rob Gaskin said:
I've got some technical description and setup info on various SUs.

I'll sort it out tomorrow and PM you to organise the best way of getting it to you (post, fax, scan).

Do you have a metal tab on the carbs with any numbers on? Mine were off a 2.2 Rover TC, 1966 and still do a grand job.
Click to expand...


Why not post it in here for us all to see?
 
Rob Gaskin said:
Do you have a metal tab on the carbs with any numbers on? Mine were off a 2.2 Rover TC, 1966 and still do a grand job.
Click to expand...

Cheers Rob
I have an ol SU manual but it doesnt list mine, but its still handy for gen ref
Will buy an upto date one off fleabay later
Just checked the tabs and it seems they are P6 Rover 2000 carbs
AUD 264F, AUD 264R http://www.burlen.co.uk/partlist.aspx?carid=9384
The needle listed isn't whats in mine so can only hope someones had it set up right?

Atleast I can see whats what now :)
 
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Oh right, sorry my info (8 pages of Haynes SU manual) is for the type of carb on my car which is HD not HS.

The D stands for Diaphram jet.

So your float chamber is connected to the jet via a flexible pipe then (like most SUs)?

Your problem with the loose jet may be a slack Jet Clamping Screw. I think you centralise the jet with the needle and then clamp it in place.

Obviously you need to straighten the needle first, which you should IMHO be able to do to get it to run ok.
 
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The needle listed isn't whats in mine so can only hope someones had it set up right?
Click to expand...

i would be surprised if it did have the listed needle as that would have proberly been a bit lean for your engine, if it has been set up right it would need a different needle to the listed one.
 
Ok so I was to ill yesterday to play so had another look today
Decided to pull the carbs off n be done with it this time

man1.jpg


Once they were out of the way I decided to pull both manifolds off as the exh gasket had obv been leaking n could be heard chuffing at tick over which annoyed me

man2.jpg



man4.jpg


man5.jpg


Sure enough that was blown so thats something else that should help


Then onto pulling the carbs apart
Having taken the jets etc out its seems these “HS8” carbs have a totally diffo jet arrangements to any SU I’ve seen before. Ie theres no adjusting nut n the jet assem does seem to just “float”. But yes Rob the float bolwn is connected much the same

man11.jpg


man111.jpg


What I did find tho was the other straight needle was set to sit proud which I don’t think is right?

man7.jpg


Also the jet bearing/ housing that holds the jets had been put together differently on each carb

man9.jpg


Spot the obv mistake :)

One thing I still haven’t worked out tho is how to I.d the jet. Cant find any no’s :conf2:
Hopefully when I get all these bits back together everything can be put back equal this time lol
 
My advice would be to get them rebuilt by an expert or get yourself a manual (even a Rover P6 one might do) and work your way through the carbs. Do it once do it right.

When I upgraded my engine I had the carbs reconditioned at the same time (through Kevin Irons) and then set-up on a rolling road. I haven't needed to touch them since (it's been about 5 yrs now!). It was money well spent.

Your inlet manifold looks like it has been 'opened-up' for the bigger carbs so good news there. MrF sells a nice thick gasket to help solve the sealing problem with tubular exhaust manifolds.

The needle does seem to be too low which would point to the jet being too low or too big.

As I say I think you need some reference material to work with first. Also perhaps someone in the club has a pair of these carbs (off a car) that you could compare yours with.

When I asked about the flexible fuel pipe from the float chamber that was to confirm that it was not the same as mine, my HD8 carbs have a casting with a diaphram in it, no pipe.
 
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Rob Gaskin said:
My advice would be to get them rebuilt by an expert or get yourself a manual.
Your inlet manifold looks like it has been 'opened-up' for the bigger carbs so good news there. MrF sells a nice thick gasket to help solve the sealing problem with tubular exhaust manifolds.

The needle does seem to be too low which would point to the jet being too low or too big.

As I say I think you need some reference material to work with first. Also perhaps someone in the club has a pair of these carbs (off a car) that you could compare yours with.
Click to expand...

SU Manuals next on the list as is the gasket :thumbs:
P6 Manual is deffo a good idea as it goes lol
Sure if someone has some of these carbys laying about that would help.

As n when it's all back together I'll get it rollin roaded n take it from there :)
 
It looks like the jet is pulled down for the choke.
The needle sticking out as far as that is a good place to start or even a little further out as it is better to see how it runs a bit on the weak side ( std 240 carb needles are out about that much).
 
Mr Ex said:
The needle sticking out as far as that is a good place to start or even a little further out as it is better to see how it runs a bit on the weak side
Click to expand...

Or in this case on my carbs make up for the fact someone has fitted the jet bearing/housing washers arse about face so the carbs will aways be odd :rolleyes: :eek:

man9.jpg
 
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