The Ford Barn

mike42 · 08-05-2015, 11:34 AM

Guys....

I've seen many threads here about gas mileage. They range for 7 to 25 mpg. I'm getting about 9 or 10, but black smoke at start up. You guys have said change the jets.....! I bought a new carb 3 years ago and just left it the way it came and drove it. What size jets should I go to in order to lower the richness ?

Thx

Mike

JSeery · 08-05-2015, 11:49 AM

It's mostly trial and error. First you need to determine what size you have now and then try two sizes smaller. Black smoke at startup may not be jets, could be other issues. You can get some suggestions for a starting point, but every engine/car combination is different and also depends on elevation, etc. But first you need to know where you are now.

Ol' Ron · 08-05-2015, 12:31 PM

Black smok ,might be a bad PV or float setting. An old timers way to check carb jets is to bering the engine up to a fast idle (1000-1200). Place the flat of your hand next to the top of you carb and slowly bring it over the opening. listen to the engine or watch the tack and if it increases in speed it's on the lean side if it doesnothing by the time your half way across it probably close and if it starts to fall off it's rich..
BUT!! I think something is wrong with the carb.

Talkwrench · 08-05-2015, 06:58 PM

What carb did you buy?

mike42 · 08-08-2015, 05:19 AM

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The carb I bought was from Dennis Carpenter I believe. I can't find the paperwork right now. The car starts right up and idles at 600 rpm perfect and smooth, but upon start up there's black soot on the ground.

I'll try putting my hand over the carb and see what happens.

Thx

Mike

08-05-2015, 11:34 AM	#1
mike42 Senior Member Join Date: Jun 2012 Location: Gaylord, Michigan Posts: 1,606	Carb Jets Guys.... I've seen many threads here about gas mileage. They range for 7 to 25 mpg. I'm getting about 9 or 10, but black smoke at start up. You guys have said change the jets.....! I bought a new carb 3 years ago and just left it the way it came and drove it. What size jets should I go to in order to lower the richness ? Thx Mike

08-05-2015, 11:49 AM	#2
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Carb Jets It's mostly trial and error. First you need to determine what size you have now and then try two sizes smaller. Black smoke at startup may not be jets, could be other issues. You can get some suggestions for a starting point, but every engine/car combination is different and also depends on elevation, etc. But first you need to know where you are now.

08-05-2015, 12:31 PM	#3
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,889	Re: Carb Jets Black smok ,might be a bad PV or float setting. An old timers way to check carb jets is to bering the engine up to a fast idle (1000-1200). Place the flat of your hand next to the top of you carb and slowly bring it over the opening. listen to the engine or watch the tack and if it increases in speed it's on the lean side if it doesnothing by the time your half way across it probably close and if it starts to fall off it's rich.. BUT!! I think something is wrong with the carb.

08-05-2015, 06:58 PM	#4
Talkwrench Senior Member Join Date: Aug 2012 Location: Perth, Western Australia Posts: 2,687	Re: Carb Jets What carb did you buy? __________________ *"Came too close to dying to stop living now!"*

08-08-2015, 05:19 AM	#5
mike42 Senior Member Join Date: Jun 2012 Location: Gaylord, Michigan Posts: 1,606	Re: Carb Jets Sponsored Links (Register now to hide all advertisements) The carb I bought was from Dennis Carpenter I believe. I can't find the paperwork right now. The car starts right up and idles at 600 rpm perfect and smooth, but upon start up there's black soot on the ground. I'll try putting my hand over the carb and see what happens. Thx Mike