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Back Firing from Exhaust and Carbs?
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jensvw
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PostPosted: Mon Mar 28, 2011 8:34 pm    Post subject: Back Firing from Exhaust and Carbs? Reply with quote

I'm trying to get my friends bug going. it has a 1641cc dual 40's mild 110 cam, i believe stock heads, stock manual fuel pump. I shot the timing and synchronized the carb's, But when revving the motor to about 200-300 it starts to back fire out of the passenger side carbs and exhaust. Would it be a fuel pump situation or just bad firing? Please info me on this. Thanks!
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mharney
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PostPosted: Mon Mar 28, 2011 8:36 pm    Post subject: Reply with quote

Dual 40 WHATs?
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jfats808
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PostPosted: Mon Mar 28, 2011 8:39 pm    Post subject: Reply with quote

Lean and or poor linkage geometry. One carb is leading the other and possibly a/f mixture screws not set properly. Pull the plugs and read em.
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jensvw
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PostPosted: Mon Mar 28, 2011 9:21 pm    Post subject: Reply with quote

Weber's
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DarthWeber
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PostPosted: Mon Mar 28, 2011 9:26 pm    Post subject: Reply with quote

Are the plug wires routed correctly? Are the carbs synchronized? What jets are in the carbs?
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jensvw
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PostPosted: Mon Mar 28, 2011 11:01 pm    Post subject: Reply with quote

Yes,sync the Carbs balanced on both sides as well as the timing.
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