WCFB Accelerator Pump linkage position?

[Mike B.]

Can someone provide a explaination on the pros/cons of the two different linkage hole options that actuate the accelerator pump on a WCFB? I am refering to the U shaped linkage held in place by a small hairpin clip residing under the metering rod cover.

Thanks,
Mike

[Mike B.]

Re: WCFB Accelerator Pump linkage position?

Is this too trivial or doesn't anyone know?

I ask because on a whim I moved the linkage yesterday from the lower to upper hole and it seemed to cure the slight haltering I was experiencing at tip-in off idle. Everything else has been tuned and retuned to spec, but I never knew about the choice of accelerator pump linkage positions. From my observations, the lower position seems to provide a shorter stroke and I presume a lesser squirt of gas.

Mike

[Clem Z.]

Re: WCFB Accelerator Pump linkage position?

the hole farthest from the shaft will give you more pump volume because you lengthened the pump stroke