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TR6 Carb / Fuel Question

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TR6 Carb / Fuel Question
#1
  This topic is about my 1974 Triumph TR6
bluefish Al Miller
Canastota, NY, USA   USA
1952 Chevrolet 3100
1974 Triumph TR6 "TR In A Basket"
Starting my TR 6 after the engine has been out of the car for a year while the car has been undergoing a complete rotisserie restoration. Engine is back in the restored car and now it’s time to start it up. The engine starts and sounds great but it will not run without squirting gas into the carbs. Checked the fuel pump and it’s delivering plenty of fuel to the carbs. After trying to figure out what is wrong I noticed the bottom plug in both carbs seemed loose and after wiggling them a slight amount gas leaked out. I pulled the plugs out and “O” rings seemed stiff and inflexible. I realize the “O” rings need to be replaced but I am wounding could this be the cause of the carbs not delivering fuel?

Any other ideas about what is causing my fuel problem?

Thanks
.

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poolboy Avatar
poolboy Ken D
Sandy Hook, MS, USA   USA
About how much gas spilled out when you removed the float chamber plugs ?

Fogspawn, CA, USA   USA
1974 Triumph TR6 "Machine"
there is no such thing as minor amount sediment inside carbuertor. Any is deadly.
forgive an oldd man, but has it been suggested the float needles might be stuck closed...
gasoline leaking from bottom of float chamber... removing the plug ... it will look like a flood,
even if measuring little volume. Carb rebuild time? be sure fuel is clean, contaminated
gasoline can look clear to untrained eye, but a carburetor can "see" it as mud entering
its little
openings...I had to address all aspects of fuel delivery, starting at fuel tank, to clean out
system before my 74 would come back to life. Had same sort of symptom as you describe.
wes

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bluefish Al Miller
Canastota, NY, USA   USA
1952 Chevrolet 3100
1974 Triumph TR6 "TR In A Basket"
Seemed like almost a 1/2 cup out of the front carb and less out of the back carb. The back carb was leaking already which was what focused my attention to the plugs.

bluefish Al Miller
Canastota, NY, USA   USA
1952 Chevrolet 3100
1974 Triumph TR6 "TR In A Basket"
The tank was cleaned and re lined with a POR system. Me lines and hoses

Fogspawn, CA, USA   USA
1974 Triumph TR6 "Machine"
sounds like carburetor condition. fuel is in the bowl.
the jet tube dips into bowl like a bird beak,
fuel enters the jet tube rising in the tube
to a level equal to surrounding pool within
float bowl chamberl. (when floats and tabs to needle valves and valves are working right)
the jet needle dips into the jet tube, call it the "well"...
the taper of needle permits increased supply of fuel as pressure drop
across bridge increases according to denand of throttle plate opening...
Dashpot piston,its diapraghm responding to pressure drop , lifting needle taper,
increasing jet opening...)
the fuel drawn from the float chamber, via pressure drop across bridge
has to be replaced, and a releving pressure has to occur in float bowl
to allow the fuel to be drawn into the intake stream ...

the choke circuit of the carb opens throttle plates slightly while introducing extra fuel
into intake stream at start from cold operating temps.
choke use is temporary and shut down manually when engine begins to cone to operating temp.

squirting fuel direct into intakes mimicks choke operation, introducing extra fuel unti
maniifold stream, then ignited in combustion chamber.
being a crude version of choke regulation, this can result in backfiring... and difficult to maintain for the time it takes engine to warm to point of not needing choke engagement.

all this meandering on my part, sorry, just trying to eason it out.
this pilgrim feels you have ignition setting close enough, to be refined when consistent running is possible.
then takes me back to the carb conditions. i would look for blockage in the carbs, clogged choke metering boxes...
something is preventing fuel flow within the carbs, i think.
if you have some fuel flow, the engine will run, even if poorly at first, getting carbs sorted out will then make it better.

in my own experience, i had to rebuild carbs twice, as even after first fuel system cleanup, i still had pixie sandd in the carbs.
i have used a camera to observe metering needle action and fuel introduction from needle opening, and throttle plate action...which might be dangerous, but interesting nevertheless. Look to carbuerttor rebuild...the dismantling, cleaning reassembly of choke boxes my least favorite part.
wes

bluefish Al Miller
Canastota, NY, USA   USA
1952 Chevrolet 3100
1974 Triumph TR6 "TR In A Basket"
Thank you for your most valuable input!!!!!

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poolboy Avatar
poolboy Ken D
Sandy Hook, MS, USA   USA
In reply to # 1508581 by bluefish Seemed like almost a 1/2 cup out of the front carb and less out of the back carb. The back carb was leaking already which was what focused my attention to the plugs.

1/2 cup...is way too much. 1 1/4 oz is more like it.

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