ORIGINAL: William Robison
[b]IronCross:
The fully machined cylindric mufflers were all pretty much the same, differing by having either a twelve mm thread for the mid blocks or a 14 mm thread for the larger engines. The small block engines, the FA-30 and so forth, had a male threaded end with no intermediate pipe. They did offer a 90 degree adapter to point the muffler to the rear on the FA-30 and similar. These little ones were 10 mm thread. I've never seen one as large as a 56 with a 10 mm thread. Is yours a really old engine?
Bill
These engines are about three years old.. I purchased them in pairs, 2 .56's and 2 .72's new from Quantum.. With each set I got one engine with the straight exaust manifold and one with the curved manifold.. The .56's and .72's have different size exhaust threads and up till this the .72 had a larger diameter (id and od) muffler... On all the above the exhaust manifold (male) screws into the muffler (female) ... As for the 10 and 12 mm size thing... I know very little about this metric measuring [
] I am getting the 10 and 12 mm from the parts description on Horizon's site and the label on the parts.. The .56 says "Muffler, 10mm SAI5074B". For the .72 the parts discription reads "Cast Muffler 12mm SAI6574C ".. Am I looking at something wrong here.. I still have a larger .72 muffler and I can measure the ID -OD of it and the replacement if you like ... Oh and the .56 and .72 exhaust sytems will not interchange.. Definite thread size differance...
