QF 750A Idle restrictor

[ojh]

I'm troubleshooting a QF 750A and see the idle restrictor is about an .031, the IAB is factory correct .061, would have thought the restrictor to be much larger. I've searched for the QF specs and they don't show the IR specs, anybody know what it should be?
Thanks, Oj

[ojh]

I forgot to mention that this is a methanol carb. The guy says it launches lazy but gets stronger going down the track.

[GTO Geoff]

Do not have anything on QF, but the old Barry Grant carbs had 029 -038 IFR for gas, & 063 for alcohol carbs.

[ojh]

[6.50camaro]

David Vizard, in his book on Holley carbs talks about re calibrating for methanol and starting at .040 for the IFR and working up to .060 as needed. just thought I throw this out there. Dan

[ojh]

I finally got thru to the Holley/QF tech and it took a while for him to find that the original IR would have been an .057.
I had a new QF 850 in earlier this week that wouldn't idle, wouldn't run at all. Turns out they forgot to set the brass cup plugs into the tops of the metering blocks, both metering blocks were missing them. Theres always something to make you go hmmm.
thanks for the input guys, i appreciate it.
Oj

[jmarkaudio]

Start around .052"