Thursday, December 2, 2010

900SS With FCR 39 and 41 Carbs

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Two 900SS, both fitted with slip on mufflers (Staintune, Gia.Co.Moto), std airbox lids without snorkles and std jetting. Before they were pretty similar:
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After, FCR41 in red, FCR39 in green. Both runs done with the same 152 main jets.
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With FCR39 before and after
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With FCR41 before and after
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2 comments:

  1. How much of the difference do you suppose is due to the A/F ratio differences? The blue trace is generally closer to stoichiometric...

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  2. I'd say on average the blue lean is as much too lean as the green line is too rich. But I doubt there'd be more power in either of them. These two runs were actually done with the same main jets (152). I tried in the 39's and then removed them and fitted 150 to it. I fitted them to the 41's to give a direct comparison, no idea why there's so much variation though.

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