• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)

TR6 Zenith Stromberg [1973 TR6] help


Freshman Member
I need some assistance with a carb problem. I have just finished restoring a 1973 Triumph TR6 with Zenith Stromberg carbs. As the car was in pieces when I started, I'm having some difficulty getting things plumbed correctly. The rear carb has what appears to be two vacum fittings on it. One on top near where it bolts to the manifold and one on the bottom. I believe the bottom fitting goes to the distributor (originally via the vacum-temp switch located on the top rad hose and now missing on my car). I have no idea where the top fitting connects to? I seem to be able to find diagrams for later years and earlier years, both of which are different as the 1973 is pre-air pump and the 72 seems different again. Thank you for any assistance.



Jedi Hopeful
It would help us visulize what you need to know if you could post some us pics.


The diagram I am looking at shows the the bottom line going to the thermostatic vaccuum switch off of the thermostat which in turn goes to the vaccuum unit at the distributor. The best I can tell, the top line feeds to the EGR valve.


Great Pumpkin
I've plugged both off, since I no longer have a vacuum switch on the radiator hose, nor do I use the vacuum retard system. But yes, that is what they were used for.


Freshman Member
I'm sorry to keep asking questions, but I'm new at this and cannot seem to find a good diagram of the correct emission and evaporative control hose system for my car (73 TR6).

My car has an Activated Carbon Canister. There are three fittings on the top of this.

One hose goes to the back of the car and connects to the top of the gas tank. The second connects what appears to be a vent fitting at the right rear of each carb and the valve cover. One is plugged. Is this correct or should this plugged fitting be connected to something?

A fitting on the side of the canister connects to the Run-on control valve mounted below the canister.

There is a second smaller fitting on the Run-on Control Valve. What is this suppost to connect to?

Thank you for any assistance and sorry I cannot post pictures as I don't have a digital camera available.



Darth Vader
I have attached an image of a 73 engine compartment with a 250 engine but with the vapor recovery system, running on, and thermostatic switch for a six installed. (When last running it still needed a smog test as a six, not a 250)

The smaller hose from the running on control valve goes to the intake manifold where the brake servo vacuum hose connects.

You should also be able to identify the vacuum hoses from the thermostatic switch between the engine and radiator.

(My car no longer needs to be smog tested, so much of the plumbing will not go back in the car)

I hope this helps.

BTW, the car is currently in process of a frame up restoration, as if it needed one.


  • 251276-smog.jpg
    93.5 KB · Views: 162
Similar threads
Thread starter Title Forum Replies Date
T TR6 My '74 TR6 Zenith Stromberg Carbs Float Bowls Leaking Gas Triumph 11
T TR6 Carb Vacuum Port- TR6 Zenith-Stromberg Carbs Triumph 2
Merlin63Tr4 TR4/4A Cracked Zenith-Stromberg float assemblies Triumph 13
B Zenith Stromberg O ring question Other British Cars 8
Zimmycobra TR4/4A Zenith Stromberg questions Triumph 13
L zenith-stromberg carbs Lotus 11
Airfix Wedge TR8 Zenith Stromberg carbs slow deceleration Triumph 1
W Zenith stromberg carbs Jaguar 3
R Zenith Stromberg CD 175 float replacements? Triumph 3
eschneider TR4/4A TR4 Zenith-Stromberg CD175 tuning question Triumph 4
M zenith stromberg? Triumph 1
martx-5 Zenith Stromberg Carbs Triumph 4
M zenith stromberg 175 cd Triumph 24
M zenith stromberg 175cd Triumph 0
M zenith stromberg 175 cd. Triumph 7
R Zenith Stromberg Running Lean - Up-date MG 1
R Zenith Stromberg Running Lean MG 7
glemon "Fixing" Zenith Stromberg Emission Control Carbs MG 4
I Zenith stromberg metering needle removal help Triumph 9
I zenith stromberg float brass plug removal help Triumph 14
I TR6 69 TR6 Zenith Stromberg carb help Triumph 1
J Zenith Stromberg question MG 4
C MGB 1979 MGB Zenith Stromberg Carburetor MG 3
H Zenith Stromberg CD 175 Too rich Triumph 7
Bret Yet another Zenith Stromberg replacement choice MG 6
S Zenith Stromberg Mixture Adjuster Restoration & Tools 13
sparkydave Fixing Zenith-Stromberg needle adjuster Spridgets 5
bluemiata90 zenith stromberg cold start adjustment Triumph 5
John75 Intro and Zenith Stromberg question Triumph 8
A Zenith-Stromberg tuning & parts MG 20
77_MG_Midget Zenith Stromberg Carbs Spridgets 6
R Zenith Stromberg basic adjustment Triumph 1
7 Zenith Stromberg Question??? Triumph 6
7 Rebuilding Zenith Stromberg MG 6
Bret Zenith Stromberg 175CD vs. SU HIF44? MG 13
doc50 For Sale Zenith carb, fits many cars. Other British Classifieds 0
sparkydave Zenith auto choke coming loose Spridgets 2
C TR6 Zenith Strombers won't start when warm. Triumph 2
sparkydave Zenith auto choke coming loose Spridgets 3
A Zenith 175 CD's Triumph 19
A Zenith 175CD carbs Triumph 9
CZ_Dave Zenith Carb MG 13
B Question- Spridget & MGB Zenith flanges? Spridgets 2
Ofcalipka Zenith single carb problems MG 62
2wrench Anybody running a BP270 cam with Zenith carbs? Triumph 2
H conversion from Zenith to SU Triumph 5
M zenith float adjustment 1979 MG 1
jerrybny Front Zenith carb overflowing Triumph 20
mgbmedic Single Zenith Carb- Results MG 1
mgbmedic Single zenith carb is a joke... MG 19

Similar threads