Seems to me that the ' How to ' series of blogs gets lots of interest?
Zenith Carburetors made the Stromberg carburetors fitted on to the 1966 Singer Chamois and Sunbeam Sport series of cars, they also made for many others, including the Rover V8 Sport and Triumph Stag, lots of cars use this carb, just the sizes change.
Once stripped and cleaned, they should end up looking like this.
Keeping things clean is the first issue, so clean the assembly with water soluable cleaner and wash clean, you will be doing this a number of times, an air hose to blow the water off helps here.
When the main body is inverted, those black floats should be 16mm high at their highest point from the edge of the carbs body. This is one of a pair of carburetors bought new from the Hillman Imp tuning experts named Hartwell of Bornemouth in England. They have seen service on our 1967 Singer Chamois for about 18 years, still in fine condition but a leaking paper gasket on the lower float bowl on one carb, had me change them for a spare pair. This way I can service them and still use the Singer.
When the floats are swung back the retaining pin can be removed and then the brass float valve can be removed. You may not find a suitable spanner in your tool kit, its an odd size in todays world, probably a BSF thread, Whitworth sockets will fit, or use an adjustable spanner?
The jet and adjustment assembly, you will need new O rings of the right size, there is also a very small one inside the washers next to the spring on the right.
As mentioned I needed to make some new gaskets, I used the correct Flexoid gasket paper from England, hand cut it with a Stanley knife and cut the holes out with the correct tool, the one I made is in the center. Note the two others are slighty different from each other, the one on the right will fit the bowl with the gasket on the left but not the other way around!
Note the central needle, this must be in perfect condition.
By this stage I have beadblasted the parts clean, re washed in water soluable cleaner, dried and then washed again in a two stroke petrol 10:1 mixx, you would be amazed at the amount of dirt that comes off the parts when this final clean is completed.
The needle should never be bent, it will not bend in use, you would have to bend it when removed from the carb, so be carefull how you handle it.
Now refitted to the water heated alloy Imp inlet manifold, we are at the end of what turned out to be a six hour job, or was it more?
To be continued!
Roy
Zenith Carburetors made the Stromberg carburetors fitted on to the 1966 Singer Chamois and Sunbeam Sport series of cars, they also made for many others, including the Rover V8 Sport and Triumph Stag, lots of cars use this carb, just the sizes change.
This is basically what they all look like, some details such as cable links will change from car to car and the side elbow which fits the Rootes Car Co Imp sports engined cars may not be fitted.
Once stripped and cleaned, they should end up looking like this.
Keeping things clean is the first issue, so clean the assembly with water soluable cleaner and wash clean, you will be doing this a number of times, an air hose to blow the water off helps here.
When the main body is inverted, those black floats should be 16mm high at their highest point from the edge of the carbs body. This is one of a pair of carburetors bought new from the Hillman Imp tuning experts named Hartwell of Bornemouth in England. They have seen service on our 1967 Singer Chamois for about 18 years, still in fine condition but a leaking paper gasket on the lower float bowl on one carb, had me change them for a spare pair. This way I can service them and still use the Singer.
When the floats are swung back the retaining pin can be removed and then the brass float valve can be removed. You may not find a suitable spanner in your tool kit, its an odd size in todays world, probably a BSF thread, Whitworth sockets will fit, or use an adjustable spanner?
The jet and adjustment assembly, you will need new O rings of the right size, there is also a very small one inside the washers next to the spring on the right.
As mentioned I needed to make some new gaskets, I used the correct Flexoid gasket paper from England, hand cut it with a Stanley knife and cut the holes out with the correct tool, the one I made is in the center. Note the two others are slighty different from each other, the one on the right will fit the bowl with the gasket on the left but not the other way around!
Most float chamber boawls on the CD125 are the same shape on each side, this pair has the corner shaped different on the left hand side. Hence the special corner on this gasket.
Note the central needle, this must be in perfect condition.
Check the brass jet in the center, the workshop manual says we should free off the lower brass body and tap it with a spanner to centralise the jet, I have always found the best method is to sight it by eye, you can move the jet easy enough with a small screwdriver, then re tighten the lower brass body.
The jet has to be central or the body with the needle in it will not seat correctly, when lifted with a finger, or in the case of this carb, a lift pin that is outside the body, thats it on the right hand side, will allow you to do it that way.
The center body with its needle, the spring which holds it down and the cap to the main body.
The needle should never be bent, it will not bend in use, you would have to bend it when removed from the carb, so be carefull how you handle it.
Now refitted to the water heated alloy Imp inlet manifold, we are at the end of what turned out to be a six hour job, or was it more?
Now ready to refit to the car, note the foam bubble wrap in the intake elbows to stop any solid body falling in.
Nice job for a winters day!
Roy
To be continued!
Roy
