I'm running a 71 T120 650cc with twin VM-32 carbs. This is a quick tip if you have ever found yourself at a loss about a "stumble" or hesitation from the start of acceleration from a stop on your Triumph, with Mikunis or Amals (remember neither have an accelerator pump). If your bike is properly tuned, both in timing AND in your carb... and that is a big if... then what you may want to experiment with is backpressure in your unbaffled exhaust. It seems as if just about every chopper nut like myself runs open exhaust. NOTHING wrong there, and keeping in mind that a motorcycle engine is basically an air pump, it seems logical that the engine would make more power with unbaffled exhaust. It DOES, usually, in limited areas, primarily WIDE OPEN throttle, which it seems like many of my riding buddies spend most of their time doing.
BUT, for many of us, you "drive torque", and surprisingly, open exhausts don't usually put out the best numbers in low end torque without SOME back pressure. IF, and I say IF, your bike is properly tuned, and your running open exhaust, try sometime putting in a little back pressure in the exhaust by drilling a hole about an inch and a half from the end, and putting a bolt in there, with a nut or two, depending on what you find. I've posted a couple of pics of how I do it, so that I can adjust the back pressure by moving the wingnut... but hell, that just is for looks... you can stick JUST the bolt in there and you might be surprised. My bike runs poorly without a little pressure back there.
BTW I love those brass tips from Lowbrow. Nice product.
BUT, for many of us, you "drive torque", and surprisingly, open exhausts don't usually put out the best numbers in low end torque without SOME back pressure. IF, and I say IF, your bike is properly tuned, and your running open exhaust, try sometime putting in a little back pressure in the exhaust by drilling a hole about an inch and a half from the end, and putting a bolt in there, with a nut or two, depending on what you find. I've posted a couple of pics of how I do it, so that I can adjust the back pressure by moving the wingnut... but hell, that just is for looks... you can stick JUST the bolt in there and you might be surprised. My bike runs poorly without a little pressure back there.
BTW I love those brass tips from Lowbrow. Nice product.
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