Albatross 100E - SU Needle
Albatross 100E - SU Needle
I'm sending my carburettor away to get it rebuilt. Before it goes does anyone know which needle it should have fitted. I have a suspecion that this is not the original unit and this may partially explain the dislike for more than one third throttle! Many thanks.
Re: Albatross 100E - SU Needle
Head here:
http://www.sucarb.co.uk
And ask them.
It's dislike of more than one third throttle, may be due to worn needle; worn jet; bent needle; mixture setting; wrong spring; broken spring; missing spring; no oil in the dashpot...
I've seen all of the above and combinations.
If you're having the carb refurbished; make sure the cost includes new needle; jet and spring. One member had a carburettor rebuilt and we subsequently found a worn, bent needle and an oval jet orifice. It was cleaned nicely through
cheers,
Scott
http://www.sucarb.co.uk
And ask them.
It's dislike of more than one third throttle, may be due to worn needle; worn jet; bent needle; mixture setting; wrong spring; broken spring; missing spring; no oil in the dashpot...
I've seen all of the above and combinations.
If you're having the carb refurbished; make sure the cost includes new needle; jet and spring. One member had a carburettor rebuilt and we subsequently found a worn, bent needle and an oval jet orifice. It was cleaned nicely through
cheers,
Scott
********************************************************************************
* Swinging the World by the tail since 1960 *
********************************************************************************
* Swinging the World by the tail since 1960 *
********************************************************************************
Re: Albatross 100E - SU Needle
Thanks Scott - I did ask their technical people and got a 'don't know'. However there is a part of their site which suggests the needle is an M6. So I'll order one of those and and new jet and the various joints etc. The rebuild service they offer preeently has a 10 to 12 week turnaround period - so I really need to fix it myself to give me some summer!
Regards
Pete
Regards
Pete
Re: Albatross 100E - SU Needle
SU carbs are fairly easy to work on, although some consider them to be the work of beelzebub.
To change the needle,
Mark the top cap so it goes on the same way round
Remove the two or three screws and lift the top off. (don't lose the spring)
Lift the piston out
undo the grub screw holding the needle in and remove the needle.
Replace needle - the shoulder on the needle should be flush with the bottom of the piston
tighten grub screw and refit piston, spring and cap.
To ensure the needle is centred in the jet, lift the piston by hand and let it drop. It should be harder to lift because of the oil in the dashpot.
There should be a positive "clunk" as it drops.
If it doesn't drop completely or doesn't clunk, the jet will need centreing. Which involves undoing the nuts holding the jet and dropping the piston right down before re-tightening the jet nuts.
To reset the mixture, run the engine at a fast idle and lift the piston about 3mm (1/8") using a wooden stirring stick from Starbucks.
If engine dies then the mixture it too lean, turn mixture control one flat anti-clockwise looking up at the bottom of the carb.
If the engine increases in speed when you lift the piston then its too rich.
If engine speed rises then drops, the mixture is about right.
Top up the dashpot oil by unscrewing the cap. 3 in 1 oil is fine, some just use engine oil.
A full rebuild of an SU carb is not much harder, just a matter of the right Whitworth spanners and a clean work area. It's all gaskets and washers. The only problem you have is if the throttle spindle is badly worn and leaking air, or one of the lugs has broken off the carb body and you can't operate the choke mixture control.
Have fun.
Cheers,
Scott
To change the needle,
Mark the top cap so it goes on the same way round
Remove the two or three screws and lift the top off. (don't lose the spring)
Lift the piston out
undo the grub screw holding the needle in and remove the needle.
Replace needle - the shoulder on the needle should be flush with the bottom of the piston
tighten grub screw and refit piston, spring and cap.
To ensure the needle is centred in the jet, lift the piston by hand and let it drop. It should be harder to lift because of the oil in the dashpot.
There should be a positive "clunk" as it drops.
If it doesn't drop completely or doesn't clunk, the jet will need centreing. Which involves undoing the nuts holding the jet and dropping the piston right down before re-tightening the jet nuts.
To reset the mixture, run the engine at a fast idle and lift the piston about 3mm (1/8") using a wooden stirring stick from Starbucks.
If engine dies then the mixture it too lean, turn mixture control one flat anti-clockwise looking up at the bottom of the carb.
If the engine increases in speed when you lift the piston then its too rich.
If engine speed rises then drops, the mixture is about right.
Top up the dashpot oil by unscrewing the cap. 3 in 1 oil is fine, some just use engine oil.
A full rebuild of an SU carb is not much harder, just a matter of the right Whitworth spanners and a clean work area. It's all gaskets and washers. The only problem you have is if the throttle spindle is badly worn and leaking air, or one of the lugs has broken off the carb body and you can't operate the choke mixture control.
Have fun.
Cheers,
Scott
********************************************************************************
* Swinging the World by the tail since 1960 *
********************************************************************************
* Swinging the World by the tail since 1960 *
********************************************************************************