The Ford Barn

fordv8j · 11-14-2018, 08:23 PM

I cleaned the plugs in my 59ab today, they were a little black, would it help to turn the 2 adjustment screws out a little, it runs really well

Fordestes · 11-14-2018, 08:39 PM

Check for over rich condition ,leaking power valve, float level, sticking choke etc. the idle mixture setting goes away at road speed.

Tinker · 11-14-2018, 09:14 PM

Also consider how you run your engine and the last time checked. A lot short runs or idling.

Check vacuum with a gauge, if your around a solid steady 18-19 then the carb idles are decent.

flatjack9 · 11-14-2018, 11:24 PM

You turn the screws in to decrease fuel. The idle system is still active during in town driving. Connect a vacuum gauge and adjust for max vacuum.

JSeery · 11-15-2018, 09:29 AM

Quote:

Originally Posted by fordv8j

would it help to turn the 2 adjustment screws out a little, it runs really well

Sounds like you are accustom to modern air adjust carbs. Older carbs adjust the fuel, not the air. When you turn the adjustment screws in it reduces the amount of fuel through the idle ports.

GB SISSON · 11-15-2018, 07:41 PM

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As a general rule, when you turn the screws in and it starts to stumble, how much to unscrew them?

Bored&Stroked · 11-16-2018, 07:24 AM

Looking at spark plugs after the car has been idling and or just driving around town - will tell you practically nothing. Also, looking at the plugs to adjust the idle is not the way to do it (as noted by many up above).

You have to run the car out on the highway under pretty much full load, then put the clutch in and kill the engine to check plugs - and with today's fuel, they usually don't "color" like back in the day. This process has nothing to do with the idle mixture - it is to validate that the main jets and power valves are correctly setup.

What you're doing is messing with the idle mixture richness - and as others have commented, you adjust for the best running condition and highest vacuum (which is pretty much the same thing in the driveway). Good luck . . . don't over think it . . .

alanwoodieman · 11-16-2018, 09:06 AM

my flatheads, at least, like to run better/cooler when the mixture is just a little rich, tuning the carb (s) for clean plugs is a jet size change or changes. I installed a set of the speedway adjustable jets in a deuce set up and was able to get pretty close to the clean plug. has anybody else installed these adjustable jets?

11-14-2018, 08:23 PM	#1
fordv8j Senior Member Join Date: Jan 2015 Posts: 325	Spark Plugs I cleaned the plugs in my 59ab today, they were a little black, would it help to turn the 2 adjustment screws out a little, it runs really well

11-14-2018, 08:39 PM	#2
Fordestes Senior Member Join Date: May 2010 Posts: 886	Re: Spark Plugs Check for over rich condition ,leaking power valve, float level, sticking choke etc. the idle mixture setting goes away at road speed.

11-14-2018, 09:14 PM	#3
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: Spark Plugs Also consider how you run your engine and the last time checked. A lot short runs or idling. Check vacuum with a gauge, if your around a solid steady 18-19 then the carb idles are decent.

11-14-2018, 11:24 PM	#4
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,525	Re: Spark Plugs You turn the screws in to decrease fuel. The idle system is still active during in town driving. Connect a vacuum gauge and adjust for max vacuum.

11-15-2018, 07:41 PM	#6
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 4,914	Re: Spark Plugs Sponsored Links (Register now to hide all advertisements) As a general rule, when you turn the screws in and it starts to stumble, how much to unscrew them? __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)

11-16-2018, 07:24 AM	#7
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: Spark Plugs Looking at spark plugs after the car has been idling and or just driving around town - will tell you practically nothing. Also, looking at the plugs to adjust the idle is not the way to do it (as noted by many up above). You have to run the car out on the highway under pretty much full load, then put the clutch in and kill the engine to check plugs - and with today's fuel, they usually don't "color" like back in the day. This process has nothing to do with the idle mixture - it is to validate that the main jets and power valves are correctly setup. What you're doing is messing with the idle mixture richness - and as others have commented, you adjust for the best running condition and highest vacuum (which is pretty much the same thing in the driveway). Good luck . . . don't over think it . . .

11-16-2018, 09:06 AM	#8
alanwoodieman Senior Member Join Date: May 2010 Location: upstate SC Posts: 2,963	Re: Spark Plugs my flatheads, at least, like to run better/cooler when the mixture is just a little rich, tuning the carb (s) for clean plugs is a jet size change or changes. I installed a set of the speedway adjustable jets in a deuce set up and was able to get pretty close to the clean plug. has anybody else installed these adjustable jets?

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