OS91FX on tune pipe
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OS91FX on tune pipe
Hi Bill,
I have an OS91FX that I want to fit a tune pipe to. I have never done this so I am doing some home work first. I have tried to measure the exhaust port timing of the engine and according to my measurement it’s about 140 degrees. Can you give me the exact timing? Some sources say that an engine with a port timing of 140 or less does not do well on a pipe, has this been your experience?
I have an OS91FX that I want to fit a tune pipe to. I have never done this so I am doing some home work first. I have tried to measure the exhaust port timing of the engine and according to my measurement it’s about 140 degrees. Can you give me the exact timing? Some sources say that an engine with a port timing of 140 or less does not do well on a pipe, has this been your experience?
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RE: OS91FX on tune pipe
Piet, if your experience with tuned pipes is limited maybe you're better off with a tuned muffler. I have Nelson Ultrathrust mufflers on two of my 91FXs and they put real life in those engines (with 12x10 props I get an additional 1700 rpm)
Check them out http://www.pspec.com/details.asp?ProdID=61&category= .
Check them out http://www.pspec.com/details.asp?ProdID=61&category= .