Yesterday's Tractor Co. Shop Now
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
Classified Ads
Photo Ads
Tractor Parts

Discussion Forums
Project Journals
Tractor Town
Your Stories
Show & Pull Guide
Events Calendar
Hauling Schedule

Tractor Photos
Implement Photos
Vintage Photos
Help Identify
Parts & Pieces
Stuck & Troubled
Vintage Ads
Community Album
Photo Ad Archives

Research & Info
Tractor Registry
Tip of the Day
Safety Cartoons
Tractor Values
Serial Numbers
Tune-Up Guide
Paint Codes
List Prices
Production Nbrs
Tune-Up Specs
Torque Values
3-Point Specs

Tractor Games
Just For Kids
Virtual Show
Museum Guide
Memorial Page
Feedback Form

Yesterday's Tractors Facebook Page

Related Sites
Tractor Shed
Ford 8N/9N Club
Today's Tractors
Garden Tractors
Classic Trucks
Kountry Life
Stationary Engines Discussion Forum

Re: Ford 172 stationary power unit

[Show Entire Topic]  

Welcome Guest, Log in or Register
Author  [Modern View]

05-01-2013 07:54:57

Report to Moderator

You wrote " I check voltage at coil, 11.75 volts coming to coil and 11.75 volts going to distributor. "

Is that with the points "open" or "closed" If the points are "open" those voltages would be normal. If the points are "closed", the coil primary terminal connected to the distributor should be art ZERO Volts. If it is NOT, the points are not making contact, which is what I suspect is happening.

HOW did you "shine up" the points? If you used any type of sandpaper or emery cloth, it is VERY likely that the points are the problem.

Post back and let's work this problem out!

[Log in to Reply]   [No Email]

05-01-2013 17:18:25

Report to Moderator
 Re: Ford 172 stationary power unit in reply to Bob, 05-01-2013 07:54:57  
I am not electrically smart when it comes to ignitions systems. I did not know it would make a difference in voltage if the points were open or closed. The numbers above is with the points open. With points closed I get 5.91 volts on the side of the resistor going to the coil. On the switch side I have 11.22 volts. On the distributor side of the coil I get .079 volts. Isn't that kind of low on the distributor side of the coil?

To shine up the points I used an already used piece of sand paper. I use the same process on the points in a wico Mag that I have not changed the points in, in over 30 years. It still runs great, but only gets used 10 to 15 hours a year.

I am leaning towards a bad coil, I don't want to buy a new one if that is not the problem. I would like to know how to test the coil. Last summer when I had this problem I was running the machine and all of a sudden it sounded like someone turned the key off. So I was thinking now that the coil got hot and failed. I should have thought of that last summer. Just a guess. I should have checked for spark out of the coil wire immediately when the engine shut down. But did not know any better.

[Log in to Reply]  [No Email]

05-02-2013 07:43:10

Report to Moderator
 Re: Ford 172 stationary power unit in reply to JOB, 05-01-2013 17:18:25  
You wrote "On the distributor side of the
coil I get .079 volts. Isn"t that kind of low on
the distributor side of the coil?"

NO! Not with the points closed.

Connect a spark tester (spare spark plug) to the secondary terminal (tower) on the coil and using an insulated tool, open and close the points.

You should see a small spark at the points each time they open and a good, hot spark coming out of the coil each time.

If not, the coil MAY be bad and the condenser is a possibility.

Here is a link to the John Deere FOS manual for ignition systems, as posted on the Farmall Cub site. That MAY give you some further insight into this.

[Log in to Reply]  [No Email]

05-02-2013 17:25:30

Report to Moderator
 Re: Ford 172 stationary power unit in reply to Bob, 05-02-2013 07:43:10  
Thanks for the help Bob, I Tried the opening the points with a screwdriver and having a grounded spark plug, and could not get a spark.

I borrowed a coil off a similar engine and put it on the 4 cylinder engine and had the same luck with the screwdriver. I then took the coil wire and held it a 1/4 inch or so from ground and spun the engine with the starter motor. Had plenty of spark. I am now up and running but one coil short.

I now understand how the ignition system works sort of. The points act as a switch, but how does the opening and closing of the switch make the coil fire? Thanks again Bob I need that chipper off and on all summer.

[Log in to Reply]  [No Email]

05-03-2013 00:48:33

Report to Moderator
 Re: Ford 172 stationary power unit in reply to JOB, 05-02-2013 17:25:30  
Quoting Removed, click Modern View to see

The buildup of a magnetic field in the coil when the points are closed and it's collapse was points open, causing a spark from the secondary winding is explained in the first 3 pages of the previously linked manual FAR better than I could!.

[Log in to Reply]  [No Email]

05-03-2013 01:21:13

Report to Moderator
 Re: Ford 172 stationary power unit in reply to Bob, 05-03-2013 00:48:33  
I looked at that link. If I would have done that when you first posted it I would not have had to ask so many questions and take up your time. When it mentioned John Deere I thought it pertained to John Deere. I should have known all ignition systems work basically the same way. Thanks Bob

[Log in to Reply]  [No Email]
[Show Entire Topic]     [Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:

Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

Home  |  Forums

Copyright © 1997-2018 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters