Small Mac Flatback Carb Drillings

Scott Kneisel · Post by **Scott Kneisel** » Thu Jan 16, 2014 9:53 pm

Something of interest to the small flatback users.

Rob Voska · Post by **Rob Voska** » Thu Jan 16, 2014 10:42 pm

Scott have you run a carb with this drill pattern?

Scott Kneisel · Post by **Scott Kneisel** » Fri Jan 17, 2014 8:07 am

Not the Alky version, as the post says, these sizes were taken from the McCulloch fuel letter that came directly from them.
I have a bunch of carb bodies that are drilled this exact way but have not tried them.
Have you Rob?

Rob Voska · Post by **Rob Voska** » Fri Jan 17, 2014 1:26 pm

No. I stick with Tilly's because I understand them & parets availability. I see a few things in the drill pattern I would change. Might have to do with us running 100 cc engines instead of 80 cc engines.... might be experience.... RPM...... weight, etc......

The small flat back and a Tilly are very similar.

I did get a kit one time from the devil in Nevada and it was for a gas carb and it was a great carb.

Brian Thomas · Post by **Brian Thomas** » Sat Jan 18, 2014 7:38 am

The devil in Nevada ,,,,,,, HA .......

Scott Kneisel · Post by **Scott Kneisel** » Sat Jan 18, 2014 12:56 pm

Yeah Rob,
I would have guessed that the Idle jet and LS adjustment hole would have been opened up more like on a Tilly mod but this is what the factory suggested so I would start from there. Actually these carbs have a smaller throttle bore and venturi than the 1" Tillys so maybe that has something to do with it.

Small Mac Flatback Carb Drillings

Small Mac Flatback Carb Drillings

Re: Small Mac Flatback Carb Drillings

Re: Small Mac Flatback Carb Drillings

Re: Small Mac Flatback Carb Drillings

Re: Small Mac Flatback Carb Drillings

Re: Small Mac Flatback Carb Drillings