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Carbs

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Carbs
#1
regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
Hey everyone

Have a carb issue.. fuel is pouring out the vent hole.. the previous owner said it might happen. Told me to take off filter & gas line to carb. Then to spray compressed air into vent hole until the gas is out of the bowl. Once the gas is out of the bowl spray car cleaner into it.

Did all that and still have gas coming out the hole.

Since I have no idea if the GT6 Carb and the Spitfire Carb are the same (as it has a GT6 engine). Can you guys help me identify which model of SU Carb I have (is there a number on them somewhere)

I want to order a rebuild kit for it

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DerbyRam54 Neville Wardle
Branford, Connecticut, USA   USA
You have two Zenith-Stromberg carbs there, not SUs. Good things come in pairs, but so did Strombergs...

There should be a small brass tag underneath one of the screws that retains the diaphragm cover (the domed bit with the black thing screwed into it). I don't see such a tag on either one of yours (and I've never seen that pattern screw used on a diaphragm cover either but no doubt somebody will have further information about that.) It helps to identify the carbs, but there are other sources of information you can use such as the metering needle. If you know what year car your engine came from that could help.

At a glance they look like 150CDSE carbs which was the most common carb fitted to most post-1970 GT6s.

Burlen's (who own the Z-S brand) can supply gasket packs, service kits (which add things like the float valve and a diaphragm for the bypass valve as appropriate) and rebuild kits (which also include throttle discs and spindle, springs and so on). None of the kits include metering needles because there are too many part numbers. I don't think they include the diaphragm either.

Burlen's are at http://zenithcarb.co.uk/?SID=vgal8gero0o78cro5rrducnd41&___store=zenith

I have no connection with Burlen other than that of a satisfied customer. Their service is generally pretty quick.

Other suppliers sell a more generic gasket pack which generally does include the float valve and a diaphragm.

From your description of the problem it sounds to me like the needle valve in the float chamber might be stuck and defeating the floats. A long time ago I used to go on long business trips to the Far East. Upon my return I would try to start my MGB. I would sit and wait for the fuel pump to stop ticking away. It usually did not stop because in my absence the needle valve had become gummed up. It was not a big deal to strip it down and clean it which would restore order.

regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
Thanks

I am new to anything British car.. and honestly am not the most experienced mechanically but can read, watch videos and do what they describe

(had a 2007 Jeep Grand Cherokee Diesel that I did most of the mechanical as it was a lemon and would have cost too much to take in to a shop.. did all that via video/reading )

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Bpt70gt Avatar
Bpt70gt Brian T
Westmoreland, NH, USA   USA
Rebuild the Strombergs, Neville has given you a good direction to go. Pretty likely the float needle valve is stuck. It's happened to a lot of us. Sometimes just lightly tapping on the float bowl chamber will free it up. BUT it may happen again soon. Time for a rebuild.

regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
So when I pull the needle are there identification marks?

regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
also, what K&N air filters will work on this

DerbyRam54 Neville Wardle
Branford, Connecticut, USA   USA
To inspect the needle you would remove the diaphragm cover (the top piece, four screws) and simply lift the air piston out of the carb as a unit, being careful not to tear the diaphragm. It might need a bit of assistance separating from the carburetter body if it has been undisturbed for a long time.

If the needle is one of the spring-loaded type you will need to gently pull on it to reveal the number which is stamped on the top part of the needle. You'll need good light and if your eyesight is failing like mine you might need a magnifying glass because the numbers are quite tiny.

According to the reference catalogue that Burlen publishes, metering needles were fitted as follows:

1972-4: B5CF
1971-2 USA:B5CF
1971 USA/Sweden: B5AJ
1969-70 GT6 MkII and 3: B5AJ
1967: B5AH
1969-70 MkII (non-US): 6AC
1966-68: 6J or 6W

I hope that might help identify what you have, it is fairly quick to look at the carb with a minimum amount of disassembling.

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Bpt70gt Avatar
Bpt70gt Brian T
Westmoreland, NH, USA   USA
Hopefully you won't have to do anything with the main needle. Your carbs do look identical to my CDSE's on my 70 GT6+.
More than likely you have a problem with your float needle, no numbers on that, they are pretty standard in the rebuild kit--unless someone has installed GROSE style jets. Some folks don't like them but I had them on my TR250 for many years. I currently have standard float needles in my GT6+. Get a couple rebuild kits and rebuild the carbs. Did the previous owner say if the carbs had been rebuilt in the not to distant past?
I rebuilt my TR carbs two years and removed the Grose jets and put on stock ones. Within a couple weeks I was driving along and fuel was pouring out the vent. I stopped beside the road and removed the filter box and tapped on the offending float bowl and it cleared up. I removed the carb after getting home and cleaned it again, didn't change anything and it's been fine for a couple years now. I suspect a tiny speck of dirt got past the fuel filter to cause the problem. I change my fuel filter now at the start of each driving season.

DerbyRam54 Neville Wardle
Branford, Connecticut, USA   USA
I doubt there's anything wrong with the needle, it's more a means of identifying the carb in the absence of the dog tag. And that's only so you can identify which service or repair kit you need if you are going with the parts Burlen supplies rather than the more generic offerings, most of which are fine.

The needle valves are all the same for carbs fitted to the GT6: Burlen part B19052. You might be lucky that a bath in carb cleaner (the needle valve, not you) sorts it out.

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Re: Carbs
#10
regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
In reply to # 1496487 by DerbyRam54 I doubt there's anything wrong with the needle, it's more a means of identifying the carb in the absence of the dog tag. And that's only so you can identify which service or repair kit you need if you are going with the parts Burlen supplies rather than the more generic offerings, most of which are fine.

The needle valves are all the same for carbs fitted to the GT6: Burlen part B19052. You might be lucky that a bath in carb cleaner (the needle valve, not you) sorts it out.

The needle valve take a bath you say.. (slowly putting pants back on now)

Re: Carbs
#11
regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
In reply to # 1496484 by Bpt70gt Hopefully you won't have to do anything with the main needle. Your carbs do look identical to my CDSE's on my 70 GT6+.
More than likely you have a problem with your float needle, no numbers on that, they are pretty standard in the rebuild kit--unless someone has installed GROSE style jets. Some folks don't like them but I had them on my TR250 for many years. I currently have standard float needles in my GT6+. Get a couple rebuild kits and rebuild the carbs. Did the previous owner say if the carbs had been rebuilt in the not to distant past?
I rebuilt my TR carbs two years and removed the Grose jets and put on stock ones. Within a couple weeks I was driving along and fuel was pouring out the vent. I stopped beside the road and removed the filter box and tapped on the offending float bowl and it cleared up. I removed the carb after getting home and cleaned it again, didn't change anything and it's been fine for a couple years now. I suspect a tiny speck of dirt got past the fuel filter to cause the problem. I change my fuel filter now at the start of each driving season.

The PO did say he did some work on the carbs a year or two ago .. not sure exactly what he did though.

Re: Carbs
#12
regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
So if there was a dog tag on the carbs where would it be located?

I emailed burlen asking which kit and they responded "Could you send us the specification number stamped on the flange of the body?"

Re: Carbs
#13
Outfect Avatar
Outfect Dave B
La Sal, Utah, USA   USA
1940 Ford N Series Tractors "Henry"
1951 Other Not Listed "SnowMan"
1979 Triumph Spitfire 1500 "White October"
1980 Triumph Spitfire 1500 "Tangerine Dream"
Dale,

Carbs that old probably have the number stamped somewhere on the radiator side of the body.
They are probably before the time they started putting on the brass tags.
Maybe 3223 or 3225. They are 150CDSE carbs.

CDSK7 is the kit number. You also need the kits for the bypass valves.


DaveInUtah

Re: Carbs
#14
regnaston Dale Sanger
Belle River, Ontario, Canada   CAN
1965 Triumph Spitfire "Frankenspit"
In reply to # 1496622 by Outfect Dale,

Carbs that old probably have the number stamped somewhere on the radiator side of the body.
They are probably before the time they started putting on the brass tags.
Maybe 3223 or 3225. They are 150CDSE carbs.

CDSK7 is the kit number. You also need the kits for the bypass valves.


DaveInUtah


thanks Dave

Re: Carbs
#15
Lizzard d id
san jose, ca, USA   USA
What problem are you trying to get at with the rebuild kits other than the fuel bowl over flow ?
If the over flow is the only problem I'd suggest not rebuilding the carbs .
....................
I'd suggest pulling one float bowl , cleaning it till it shines , replacing the needle and seat , setting the float level and then putting it back together and taking it for a drive . If it starts and drives well , then I'd suggest pulling the other carbs float bowl for the same same .

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