![]() ![]() I image the procedure to be identical for any ZS carburettor fitted with TC’s.įirst remove the bi-metallic strips. The following is the procedure I used on my 1974 1/2 model TR-6, fitted with Zenith-Stromberg 175CD-SEVX carburettors. Stromberg 175 cd 2 manual how to#The specifications on how to adjust the TC’s were a closely guarded secret at the Zenith Carburettor factory and were never revealed to any known, living person! However in doing so, you must remove the adjusting nut, and unless you knew that the middle nut was an adjustment….you were doomed. When this happens the owner usually pulls the TC’s apart, removes the bi-metallic strip, cleans off the gunk and puts it back together again. The other end of the strip engages a plastic plunger with a conical end which slides in a cylindrical extension of the housing and thus forms a regulating valve.Ĭhanges in temperature causes the bi-metallic strip to flex, moving the plunger in its bore, regulating the annular area around the bore thus controlling the amount of by-pass air that is allowed into the carburettors mixing chamber.”Ī common problem with the TC’s is that the plastic cylindrical plunger becomes stuck, either open or closed due to buildup of gunk. “The temperature compensator (TC) is a rectangular housing with a plastic cover that contains a bi-metallic strip, one end is secured to the housing with a screw or rivet, and an adjusting nut is located part-way along its length. You need JavaScript enabled to view it.The Art of Temperature Compensator Adjustmentīy Steve Sutton, exactly are Temperature Compensators? To paraphrase the Haynes ‘Zenith-Stromberg CD Carburettor’ owners workshop manual: If you have any questions, call me at 70 or email me at This email address is being protected from spambots. The key word here is “OVERHAULED PROPERLY”. When a Marvel-Schebler is used on a tail-dragger, the fuel level in the bowl obviously does not touch the gasket thus eliminating the “fuel seep” condition.Īll in all, The Stromberg is an excellent little carburetor when serviced and overhauled properly. The Marvel’s float bowl holds a higher volume of fuel than a Stromberg and the float level is lower than a Stromberg’s. People ask “why does this happen on a Stromberg and not on a Marvel-Schebler carb. Note the fuel level at the 12 degree position… The pictures show the fuel level in the bowl and at a 12 degree incline. This leak becomes evident by a small line of blue fuel dye at the rear and sides of the float bowl mating surfaces. ![]() The fuel eventually seeps thru the gasket and ends up with a very slight leak at the outer edge of the gasket. The gasket between the castings now gets wet and starts wicking up fuel from the float bowl. The fuel in the carb’s bowl now sits un-level and rests on the rear parting surface of the upper and lower castings. The fuel level, which was originally set in a “level” position on the flow bench, now sits at a 12 to 15 degree angle from level with the tailwheel on the ground. In replacing or fitting a new metering needle the shoulder must line up with the lower face of the air valve and the locking screw tightened fully. If examination of the needle indicates it is bent it should be replaced with a new one bearing the specified marking as detailed in the specification for the particular make and model of engine. In common with other products made from rubber compounds any contact of the diaphragm with volatile cleaners such as tri-chloroethylene should be avoided. If it is necessary to clean the diaphragm, use only clean rag. The outside of the air valve and the bore can be wiped clean with a rag that is moistened with paraffin or petrol but if the diaphragm has expanded one will have to allow it to dry for a few minutes before it will fit on the bead and recess for the locating tab. To remove the air valve assembly take off the top cover by undoing the screws 2 when the assembly with diaphragm can be lifted out of the main body. Sticking of the air valve can be explained by dirt or carbon on the outside diameter of the air valve and the bore in which the air valve moves or if the metering needle is bent. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |