Re: Lumpy tick over.
Posted: Sun Oct 06, 2019 3:08 pm
Cass
You will find it a great advantage to couple up a temporary fuel feed to the carbs before fitting them to the engine, and applying pump pressure. The weak links are the four sealing points at the end of the fuel feed alloy link from the front carburetter to the choke assembly. If any of those four seals leak you will need to remove both carburetters again, so it is worthwhile ensuring you have no leaks. It is possible you may find these joints troublesome to cure as the limitations are the alloy threads in the castings.
Unfortunately the float chamber banjo fittings have some limitations of their own and tend to unscrew, it is therefore good practice to drill the banjo bolt heads to accept locking wire.
Did you manage to get the banjo bolt withdrawn that connects the alloy link to the choke unit, or was it seized on the threads?
Although your kit will have been labelled for HD6 units to some extent it will be generic. Generally the carb build spec on a S type will be AUD154, even though that was originally listed by S.U for use with oil bath air cleaners only. They listed four carb build specs for S Types viz AUD 109, AUD 243, AUD 153 and AUD154, also some 14 build specs for 3.8 ltr XK engines alone from 1960 to 1967 nearly all with HD6 carbs. These changes invariably lead to excess supply of odd parts in kits, although it is always wise to check if items have been missed off.
You will find the build spec for an AUD154R, (rear carb) excludes a float chamber tickler pin. The best advice anyone could give you is to either convert, or replace the rear carb float chamber lid to incorporate a tickler pin. Ensure the pin is cut off to size to stop a foul with the rising float. When combined with the front carb that should have a pin this ensures easy testing for the presents of fuel in each chamber, and the ability to flood both float chambers especially for low temperature cold starts. If you order a new chamber lid, beware they are handed and the rear one is the rarer.
I can understand why Burlen do not include needles in their kits as the variations are enormous, in addition many users alter needles to try to cope, in their view, with modern conditions. I use TM needles for instance.
I notice that you have presumably taken off, and intending replacing the carbs as a unit together. I find it much easier to remove the rear carb first, and replace it last, rather than struggle with both carbs together. In addition I use bar turned bronze exhaust nuts on the carb flange studs. These nuts are slightly longer than the original ones, but easy to remove and replace.
Best of luck with your replacement and keep us informed.
Norman
You will find it a great advantage to couple up a temporary fuel feed to the carbs before fitting them to the engine, and applying pump pressure. The weak links are the four sealing points at the end of the fuel feed alloy link from the front carburetter to the choke assembly. If any of those four seals leak you will need to remove both carburetters again, so it is worthwhile ensuring you have no leaks. It is possible you may find these joints troublesome to cure as the limitations are the alloy threads in the castings.
Unfortunately the float chamber banjo fittings have some limitations of their own and tend to unscrew, it is therefore good practice to drill the banjo bolt heads to accept locking wire.
Did you manage to get the banjo bolt withdrawn that connects the alloy link to the choke unit, or was it seized on the threads?
Although your kit will have been labelled for HD6 units to some extent it will be generic. Generally the carb build spec on a S type will be AUD154, even though that was originally listed by S.U for use with oil bath air cleaners only. They listed four carb build specs for S Types viz AUD 109, AUD 243, AUD 153 and AUD154, also some 14 build specs for 3.8 ltr XK engines alone from 1960 to 1967 nearly all with HD6 carbs. These changes invariably lead to excess supply of odd parts in kits, although it is always wise to check if items have been missed off.
You will find the build spec for an AUD154R, (rear carb) excludes a float chamber tickler pin. The best advice anyone could give you is to either convert, or replace the rear carb float chamber lid to incorporate a tickler pin. Ensure the pin is cut off to size to stop a foul with the rising float. When combined with the front carb that should have a pin this ensures easy testing for the presents of fuel in each chamber, and the ability to flood both float chambers especially for low temperature cold starts. If you order a new chamber lid, beware they are handed and the rear one is the rarer.
I can understand why Burlen do not include needles in their kits as the variations are enormous, in addition many users alter needles to try to cope, in their view, with modern conditions. I use TM needles for instance.
I notice that you have presumably taken off, and intending replacing the carbs as a unit together. I find it much easier to remove the rear carb first, and replace it last, rather than struggle with both carbs together. In addition I use bar turned bronze exhaust nuts on the carb flange studs. These nuts are slightly longer than the original ones, but easy to remove and replace.
Best of luck with your replacement and keep us informed.
Norman