Stromberg CDSE emmission control carbs

[pei]

Hi all,
I am trying to syncronize my CDSE carbs on my 1970 GT6+.

The back carb is sucking less air then the front. and when I lift the air valve with a screwdriver the engine bogs, which indicates a lean mixture. With this said, there is no adjustment on the bottom of the carbs like on the CD150, only an idle screw, a fast idle screw and an idle trim screw which requires a CO2 analizer on the exhaust to set to the correct mixture.

How do I syncronize, balance and adjust the mixture.

Any ideas?
Joe

 

[philman]

send me a pm, I think I may have something to help you. not specifically for gt6's or triiumphs.

 

[bobh]

I've seen a warped intake manifold cause the same problem. Check to see if there are any gaps or hissing sounds coming from the manifold gasket.
If these are like the 175 carbs the needle is adjustable from inside the damper tube. There is a job specific tool that can be used without removing the top of the carb and the air valve. You can see it in the catalogs. It's basically an allen wrench with tabs sticking out either side to sit in the slots at the top of the damper tube. The tabs allow you to turn the adjusting screw and keep the air valve from rotating (and tearing the diaphram). Or you can take the top of the carb off, remove the piston and adjust the needle while holding the piston in your hand. I prefer to do it this way. There is a screw that goes in the side of the piston to hold the needle assembly. It is usually soft brass. I like to back off this screw before adjusting the needle. Once (and only once) I paid a shop to set up my carbs. They didn't do a good job. When I started to set them up myself I found thay had destroyed the set screw and damaged the needle assembly.
If you decide to do this. Adjust both needles to the same number of turns, reassemble the carbs and make your adjustments from there. Once you have them syncronized, take them apart and tighten the screw a little to keep the setting. It's a little more tedious than having the proper tool, but it works for me.

 

[pei]

Success!!!
I stripped the back carb down as per advice from a LBC mechanic, he thought there was dirt in the seat. It was clean. I then went back to the manual and noticed on the emmission control carberaters, there is an extra air intake through the breather assembly on each carb. The guy who had done the tuneup for me had glued the gasket on to the breather and siliconed over the air hoples on the back carb and half the front. I cleaned the gasket cement and installed new gaskets. Just took it for a test run and smooth and powered through 5000RPM, no hesitation in idle and no more smell from the exhaust!
Off to British Car Days this weekend on PEI,Canada.We are expecting 300 plus cars from various parts of North America.