The Ford Barn

bgalla · 09-06-2022, 02:35 PM

This is a 36, entirely stock,21 stud engine with a Stromberg Carb. It runs like a top, but I only get 8-9 MPG. Checking two plugs next too each other they both are black so I must be dealing with a rich mixture. Is this totally the carb? If so what is the most common cause of a rich mixture in this 97? Thanks Bruce

Jacques1960 · 09-06-2022, 05:59 PM

Easy part first: How long do you leave the choke when starting / warming up ? Does it truly go in all the way when you push it in ? Has timing been verified ?

Jacques1960 · 09-06-2022, 06:09 PM

PS - you can locate / print the Stromberg manual from the company web site; this includes easy to understand idle jet adjustment instruction

Tinker · 09-07-2022, 01:21 AM

As mentioned look at spark. Not saying a flathead is a super efficient motor. But you should get a bit better then that. Lot of factors including compression.

Terry,OH · 09-07-2022, 10:17 AM

Suggest you remove both of the main jets and the power valve. Nearly all are stamped with their size. Stock size is .045 main & 65 power. It is possible the power valve is leaking.

bgalla · 09-08-2022, 01:50 PM

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Thanks for the advice. I did check the choke and it opens fully. It runs fine but I have not rechecked the timing since I started driving it, only about 150 miles ago, after rebuilding the engine completely. I did rebuild the carb at that time. I don't know about the power valve, but does one need a special tool to remove it? Sorry about the delay in response but was out of town yesterday. thanks again

Terry,OH · 09-09-2022, 07:51 AM

You need a special tool for the main jets only. It is available through Stromberg on their web page.

09-06-2022, 02:35 PM	#1
bgalla Member Join Date: Aug 2011 Location: Chico,Ca Posts: 72	36 running rich This is a 36, entirely stock,21 stud engine with a Stromberg Carb. It runs like a top, but I only get 8-9 MPG. Checking two plugs next too each other they both are black so I must be dealing with a rich mixture. Is this totally the carb? If so what is the most common cause of a rich mixture in this 97? Thanks Bruce

09-06-2022, 05:59 PM	#2
Jacques1960 Senior Member Join Date: Sep 2020 Location: Mount Desert, Maine Posts: 504	Re: 36 running rich Easy part first: How long do you leave the choke when starting / warming up ? Does it truly go in all the way when you push it in ? Has timing been verified ? __________________ No job’s done ‘til it’s all done

09-06-2022, 06:09 PM	#3
Jacques1960 Senior Member Join Date: Sep 2020 Location: Mount Desert, Maine Posts: 504	Re: 36 running rich PS - you can locate / print the Stromberg manual from the company web site; this includes easy to understand idle jet adjustment instruction __________________ No job’s done ‘til it’s all done

09-07-2022, 01:21 AM	#4
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: 36 running rich As mentioned look at spark. Not saying a flathead is a super efficient motor. But you should get a bit better then that. Lot of factors including compression.

09-07-2022, 10:17 AM	#5
Terry,OH Senior Member Join Date: May 2010 Posts: 4,751	Re: 36 running rich Suggest you remove both of the main jets and the power valve. Nearly all are stamped with their size. Stock size is .045 main & 65 power. It is possible the power valve is leaking.

09-08-2022, 01:50 PM	#6
bgalla Member Join Date: Aug 2011 Location: Chico,Ca Posts: 72	Re: 36 running rich Sponsored Links (Register now to hide all advertisements) Thanks for the advice. I did check the choke and it opens fully. It runs fine but I have not rechecked the timing since I started driving it, only about 150 miles ago, after rebuilding the engine completely. I did rebuild the carb at that time. I don't know about the power valve, but does one need a special tool to remove it? Sorry about the delay in response but was out of town yesterday. thanks again

09-09-2022, 07:51 AM	#7
Terry,OH Senior Member Join Date: May 2010 Posts: 4,751	Re: 36 running rich You need a special tool for the main jets only. It is available through Stromberg on their web page.