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TR6 Tr6 stromberg carb gas leak from starter valve bolt shaft


Freshman Member
This just happens on the rear carb when I choke to start the car. Carbs have been rebuilt with a new gasket from the starter valve to the carb body. Goes away when the car is warmed up and the choke is all the way in. Anyone seen this before. Drips out awful close to the exhaust header. Thanks in advance.



Country flag
It may be impossible to see without disassembly or at least removal of the fast idle cam, but there is a small weep hole or 'vent' below the shaft. That's more than likely where the drip starts.
Seen here at about 3 o'clock:

First the easy stuff. Orient your "dome" correctly. The 'writting' is meant to be read from the cockpit.
Line these index marks up:

Still... it sounds like fuel is escaping or overfilling the hollow disc, which provides the pathway for the fuel thru the starter box.
See if you still have the drip with the air box and the air box to carb gasket removed, taking notice of gasket hole alignment with holes in the carb's air box mounting flange.
If it looks OK and does still drip then make sure the throttle disc was installed oriented correctly, with the 2 dot projections (projections, not indentations) below the throttle shaft.

If that's OK, then check the float chamber jet and floats for level and function. And if you have Grose jets, replace them.
Any one of those situations could cause that dripping, but if you find none of the problems as described, let us know.


Freshman Member
Dome was orientated 180 degrees. Fixed that - THANKS!. Had the drip even with the air box and gasket removed. As to checking throttle disk orientation - will have to wait till it is warmer - was -8 here in VT this morning and the TR is in the barn not the warm shop. When I rebuilt the carbs this summer, I replaced the jets and set the floats - may have done it wrong but the other carb does not leak (did carb rebuild on both).

One question I have - My needle is fixed - not adjustable. Is it recommended to change this to an adjustable needle?

Thanks for your help!


Country flag
Adjustable needles are nice and a convenient way of adjusting the mixture..The range of movement is about 1/8 inch, but within that range you can zero in to a good mixture most of the time..
Once you drive for about 300-500 miles, if you pull the spark plugs you can evaluate the color and determine if the mixture needs adjustment. Then, even though it's not as convenient you may be able to alter the height of the fixed needle.
Loosen the set screw and pull the needle down to lean, or to enrichen, see if you have room to push the needle higher; if not shorten the needle carrier.

Just remember even with an adjustable needle set at the mid point of it's adjustment range of 1/8 inch, you only have 1/16" to play with.
About all I could suggest aside from what I already have is go thru the dripping carb as see if you did anything different. Make sure the choke's hollow disc has enough spring pressure behind it to keep it pressed against the body of the carb and there are no grooves that might be diverting the fuel into the starter box housing

AND if you put Grose jets instead of the original needle valves, replace the original needle valves unless you have reason to believe they were malfunctioning..Even if you replaced the old needle valves sometimes even the brand new needle valves stick open, so think about putting the old ones back
One last thought for tonight..make sure the dripping carb is not dominating.
Check the balance between the 2 carbs again.
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