My 1978 Sport has the carb connections to the inlet of the cylinder with a metal flange. There is a plastic insulating spacer identified as an 'Anti-thermic flange'. Mine's cracked and I am struggling to find a replacement (any ideas?). That said, I notice that a lot of people convert this carb type cylinder head connection to a rubber mount as was the move by Morini later in the production.
I have not been able to find any schematics on the rubber mount (Blue Book, Dellorto etc.) but from other posts it seems that there is the threaded steel stub (I have sourced) , rubber connecting pipe (Start Gomma/Mdina) secured with jubilee clips, and if I understand correctly an internal sleeve to connect the carb outlet to the rubber inlet pipe. Can anyone tell me the part number, or where I can source that internal sleeve as I cannot locate it on the dellorto.co.uk site?
Grateful if anyone has a picture or can point me towards a schematic to show all these components hooked-up, so I can check I have all the parts.
Many thanks
Carb inlet rubber mount
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George 350
- Posts: 452
- Joined: 16 Jun 2007 09:43
- Location: Northampton
Re: Carb inlet rubber mount
Inlet sleeve.
The piece you are referring to goes into the front of the carb to take up the space where the manifold stub used to go - the rubber inlets fit over the outside of the carb.
I've not got a part number for this sleeve, but they are easy to make if you can't get any. Basically it is a top hat shaped sleeve, internal dia 25mm, outside dia same as carb manifold stub, length is same as depth on front of carb where manifold tube ised to go, top hat flange about 1mm thick, outer dia of rim same as o.d. of carb body. While from a gas flow perspective it is best to have them,
many people have run without them fitted and suffered no issues. I'll keep looking to see what I can find.
Regards, George
The piece you are referring to goes into the front of the carb to take up the space where the manifold stub used to go - the rubber inlets fit over the outside of the carb.
I've not got a part number for this sleeve, but they are easy to make if you can't get any. Basically it is a top hat shaped sleeve, internal dia 25mm, outside dia same as carb manifold stub, length is same as depth on front of carb where manifold tube ised to go, top hat flange about 1mm thick, outer dia of rim same as o.d. of carb body. While from a gas flow perspective it is best to have them,
many people have run without them fitted and suffered no issues. I'll keep looking to see what I can find.
Regards, George
George
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
-
George 350
- Posts: 452
- Joined: 16 Jun 2007 09:43
- Location: Northampton
Re: Carb inlet rubber mount
George
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
350 sport 1978, 350 Strada 1978
650 Norton 1967, 650 Kawasaki 1977 and 650 Enfield 2019
Re: Carb inlet rubber mount
Thanks for the information George,
I did see the earlier post and have been trying to track down the 'black' sleeve. I get now how it all connects, although installing ready-made OEM/replica sleeves would be my preference if they still exist. I'll drop Mdina a note now that I am a bit clearer on the what!
Many thanks
- Darren
I did see the earlier post and have been trying to track down the 'black' sleeve. I get now how it all connects, although installing ready-made OEM/replica sleeves would be my preference if they still exist. I'll drop Mdina a note now that I am a bit clearer on the what!
Many thanks
- Darren
Re: Carb inlet rubber mount
NLM used to make the sleeve in aluminium.
Re: Carb inlet rubber mount
There are the VHBZ 25 BS that are used with the metal manifolds without the black sleeve. The "tube" towards the cilinderhead is slottet so you can fix it with a clamp on the metal manifold. When using the rubber manifold you better insert the black sleeve to avoid a step in the gas flow.
And there are the VHBZ 25 HS,that are not slotted. This ones you cannot use with the metal manifolds and have the additional black sleeves. These VHBZ 25 HS also have the vacuum tubes to put on manometer, depresion fuel taps, mecanical scott oiler and stuff like that. Often there is a tube between these brass tubes to tranquilize the idle, otherwise they must be closed.
The ventilation of the float chamber of the BS usually are half sealed with a metal seal that allows breathing. The HS instead have small brass tubes where you can put on tubes that lead unter the tank (the enduros have it that way not to loose gasoline when falling down). Some tremezzo drivers complain problems when there ist strong wind from aside. I´m quite sure that they have mounted the BS version.
This ventilation (seals like tubes) are on both sides of the carbs (outside where we have the screws and inside where the gasoline arrives). I found out that the drilling of the housing is not done on the outerside at the HS, so no need of a tube up to the tank. At the BS the drilling is not done on the inner side
Aditionally there are very small drillings directly to the ventilacion chimneys at both models, as well as to the choke chimneys.
Last week I spent some hours looking at my carbs and also noted that I have 3 different bodies of Dellortos all named PHBH 28 BS At least from 1981 to 1884 they have totaly diferent idle circuits compared to later models (but all are named the same). I´m going to write a little article about that stuff for the next Strega. I suppose that at least one of you receive our magazine and perhaps could translate it, if there is interest 
cheers
norbert
And there are the VHBZ 25 HS,that are not slotted. This ones you cannot use with the metal manifolds and have the additional black sleeves. These VHBZ 25 HS also have the vacuum tubes to put on manometer, depresion fuel taps, mecanical scott oiler and stuff like that. Often there is a tube between these brass tubes to tranquilize the idle, otherwise they must be closed.
The ventilation of the float chamber of the BS usually are half sealed with a metal seal that allows breathing. The HS instead have small brass tubes where you can put on tubes that lead unter the tank (the enduros have it that way not to loose gasoline when falling down). Some tremezzo drivers complain problems when there ist strong wind from aside. I´m quite sure that they have mounted the BS version.
This ventilation (seals like tubes) are on both sides of the carbs (outside where we have the screws and inside where the gasoline arrives). I found out that the drilling of the housing is not done on the outerside at the HS, so no need of a tube up to the tank. At the BS the drilling is not done on the inner side
Aditionally there are very small drillings directly to the ventilacion chimneys at both models, as well as to the choke chimneys.Last week I spent some hours looking at my carbs and also noted that I have 3 different bodies of Dellortos all named PHBH 28 BS
At least from 1981 to 1884 they have totaly diferent idle circuits compared to later models (but all are named the same). I´m going to write a little article about that stuff for the next Strega. I suppose that at least one of you receive our magazine and perhaps could translate it, if there is interest cheers
norbert