Denny K
Veteran Member
Folks
During my effort to rebuild the VB21 carbs for my 1979 CB400T I managed to damage the head of the emulsion tube located under the secondary jet on one of the carbs. (See Page 3 of Jim’s link on Rebuilding VB Carbs.) I was carefully following Jim O’Brien’s instructions and had made up the 4mm x 1mm screw driver, but I didn't do a good job. After damaging the first one, the other tube came out okay because I put liquid wrench in the hole of the second carb and let it sit. I found that putting a wooden tooth pick in the hole would keep the fluid in place so as to loosen up the brass threads. If I had done this on the first carb, I may not have damaged it. Lesson Learned!
I consulted with Jim and he told me there are two options, stop where you are and forget it or buy new ones and extract the damaged one. He also gave me a link to purchase the new tubes. Please note that Jim told me you need to replace both tubes so they are the exactly the same in each carb. When you buy them you get two to a package.
After doing a lot of research on small extractors, I decided on the Irwin EX-1, which was less than $3 at a local hardware store. I had been soaking the damaged tube for several days and finally got up the courage to give it a try. I carefully enlarged the hole using the 5/16" drill bit in a pin vice until I could feel that the bit was dropping into the tube. I tried to use the pin vice to hold the extractor but the chuck was too weak. With the extractor set and centered, I used my small vice grip and locked it onto the square tail of the extractor and with slow and even pressure got the tube to start turning out. I cleaned up the orifice and then installed one of the new tubes. Initially is did not go down far enough, so I screwed it back out, cleaned some more, put a bit of liquid wrench on the threads and tried again; it bottomed out. Yeah!
During my effort to rebuild the VB21 carbs for my 1979 CB400T I managed to damage the head of the emulsion tube located under the secondary jet on one of the carbs. (See Page 3 of Jim’s link on Rebuilding VB Carbs.) I was carefully following Jim O’Brien’s instructions and had made up the 4mm x 1mm screw driver, but I didn't do a good job. After damaging the first one, the other tube came out okay because I put liquid wrench in the hole of the second carb and let it sit. I found that putting a wooden tooth pick in the hole would keep the fluid in place so as to loosen up the brass threads. If I had done this on the first carb, I may not have damaged it. Lesson Learned!
I consulted with Jim and he told me there are two options, stop where you are and forget it or buy new ones and extract the damaged one. He also gave me a link to purchase the new tubes. Please note that Jim told me you need to replace both tubes so they are the exactly the same in each carb. When you buy them you get two to a package.
After doing a lot of research on small extractors, I decided on the Irwin EX-1, which was less than $3 at a local hardware store. I had been soaking the damaged tube for several days and finally got up the courage to give it a try. I carefully enlarged the hole using the 5/16" drill bit in a pin vice until I could feel that the bit was dropping into the tube. I tried to use the pin vice to hold the extractor but the chuck was too weak. With the extractor set and centered, I used my small vice grip and locked it onto the square tail of the extractor and with slow and even pressure got the tube to start turning out. I cleaned up the orifice and then installed one of the new tubes. Initially is did not go down far enough, so I screwed it back out, cleaned some more, put a bit of liquid wrench on the threads and tried again; it bottomed out. Yeah!
