Author Topic: APT adjust ???  (Read 2234 times)

Offline Rooster

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APT adjust ???
« on: August 11, 2023, 11:36:04 PM »
Fine tuning my rebuilt 17080212.   Got the idle screws 2 turns out and trying to set the APT.   At 3.5 turns out , when closing the choke flap @ 2,000  the engine rpm momentarily speeds up then engine bogs down. Does that means it's too rich or too lean ?

Offline Kenth

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Re: APT adjust ???
« Reply #1 on: August 12, 2023, 03:22:59 AM »
If you see about 50-150 rpm increment before the engine chokes you´re fine.

Offline Rooster

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Re: APT adjust ???
« Reply #2 on: August 12, 2023, 08:50:17 PM »
Thankyou.   I took the car for a drive today.   Not the same amount of grunt as before re-build.  But I put that down to worn jets / primaries giving more fuel.  So I wound the APT out 1/2 a turn more and there seems to be a slight improvement, so I'll leave it at that.

Offline MattK2

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Re: APT adjust ???
« Reply #3 on: September 14, 2023, 05:58:56 PM »
I observed a that too on my carb. Wide open choke plate, the engine has a little roughness to it, slowly close the choke before starving it from air and the rpm increases, idle gets really smooth and 1” gain of vacuum. If that’s ok, great. Be nice to have a little smoother idle tho.