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Author Topic: How much back preasure?  (Read 1558 times)

luoma

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How much back preasure?
« on: August 10, 2007, 02:23:29 AM »
I have the classic exhaust from the CMW performance kit and am thinking about drilling out the baffle for more noise. I like a good loud bark out the tail pipe, but am concerned about altering performance in a negative way. I have drilled a few tiny holes already to help lean out the mixure (new carb ran way too rich).

Kevin Mahoney

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Re: How much back preasure?
« Reply #1 on: August 10, 2007, 03:46:51 AM »
Have your way with it. Drilling out the baffle will increase flow some and may in fact be a good thing. The key is to make sure that you re-jet the carb when you have settled on a configuration

luoma

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Re: How much back preasure?
« Reply #2 on: August 10, 2007, 10:55:47 PM »
Thanks, I think I will open it up a bit more. Even with no silencer, these bikes are not as noisy as the custom V-twins roaring up and own the road.

I think I've got the carb just about right. When I first installed it, it was very rich, si I moved the clip on the needle one notch. That seemed to help, but the plug was still a bit sooty, Not enough however to move the needle another notch, so I put a few 1/4" holes in the baffle by going in through the inlet side of the silencer. It's still pretty quiet and the plug is cleaner.