The Serial Numbers Of

ASSOCIATED MANUFACTURERS Co.

WATERLOO, IOWA

I would like to explain this database  and as with any part of this web page it is an ongoing uphill battle of research, gathering information at shows by taking pictures of Associated engines and recording their characteristics,  and documenting the serial numbers that go along with these characteristics.  Any of this information can be either wrong or in need of adjustment and I will adjust and or make corrections as I find and discover more basis of fact as it relates to serial numbers, development of Associated engines and the dates of manufacture.  Any and all info is appreciated and if you own or know of an Associated engine and would like to submit a description of the engine along with the serial number that would be appreciated.

The Associated Serial Number Data Base Table below is a compilation of information.  It is believed by me that late in 1916 the trip style was changed from the straight trip to the "improved" style goose neck style trip.  I have a copy of the June 1916 edition of "The Chore Boy" magazine, which was a publication for dealers and distributors of Associated Manufacturers Co. engines, and the illustrated engines still have the straight trip and since I am assuming that any of the latest improvements would surely be illustrated in such a publication, I would guess that the change from the straight trip to the goose neck improved trip was after June 1916.  The chart following the production date chart gives the cut off serial number for the change from the straight style trip to the improved trip.  I have also found a reference that states that on 1 January 1924 the Associated Manufacturers Co increased the power ratings of all engines.  This meant the Chore Boy went from 1 3/4 to 2HP, the Hired Man went from 2 1/4 to 2 1/2HP and the Three Mule Team went from 3 to 3 1/2 HP etc...  I am assuming that this is also the time that the "Iowa Oversize" name was used to describe the engines.  It was also around this time that the change to the smaller 2-Bolt John Deere style magneto, also known as a Number 25 Magneto (The earlier 4-Bolt magneto was known as a Number 10 Magneto) was also made.  I have not as of yet documented such a change but I believe that the increased HP ratings of the Iowa Oversize engines was due to increased flywheel weight, larger valves and higher RPM.  I own a Repair List & Instructions booklet that lists the serial number cut off for the Jan 1924 change to the Iowa Oversize design.  Refer to the following Table:

Iowa Oversize Starting Serial Numbers as of 01 January 1924
Engine Type /

New HP Rating

1 1/2HP

Air cooled and Water Cooled

2HP

Air cooled

2HP

Water Cooled

2 1/2HP

Air Cooled

2 1/2HP

Water Cooled

3 1/2HP 6HP 8HP 10HP 12HP
Starting Serial # Not Listed 37070 338001 158100 161150 512750 420000 612010 802800 901520
Old HP Rating 1 1/2HP 1 3/4HP 1 3/4HP 2 1/4HP 2 1/4HP 3HP 4HP 6HP 8HP 12HP
#25 Mag used as of Not Listed 37000 336000 158000 160000 512000 420806 Not Used Not Used Not Used

 Assuming that the serial numbers are sequential, notice that as of Jan 1924 51,150 water cooled Hired Man engines were built  (the 150000 to 159999 block being reserved for the Hired Hand engines) as compared to a mere 1520 12 Mule Team engines.  This would also lead me to believe that The Hired Man was the best selling model followed by the water cooled Chore Boy which is supported by the fact that the most common engine still in existance is the Hired man engine.  The short lived 3 Mule Team only selling 12,750 engines because it was first introduced in 1915.

Trying to determine when exactly Associated engines went from the 4-Bolt bronze magneto to the 4-Bolt pot metal mag would be virtually impossible unless actual documentation from the factory was found.  I doubt that will ever happen!   Update!!!  I have found the exact serial number that the change from 4-bolt to 2-bolt magneto occurred as listed in my recently acquired AMANCO price list for repair parts.  This information is listed above as "#25 Mag used as of".

In 1923 the 4HP was re-rated to 6HP and underwent severe design changes in doing so.  The water hopper was extended to overcome inherent cooling problems, the valve diameter was increased and the bore was increased from 4 3/4" to 5".  The RPM was also was increased from 400 to 470 

____________________________

The following table is entirely my own fabrication.  It is nothing more than a guide and should be assumed to be nothing more than that.  No production/serial number records exist that I am aware of  for Associated Manufacturer Co. engines and since there is no other guide to possibly date the manufacture of an Associated made engine, I have created this table by dividing production numbers with serial number information that states what serial existed on of both about October 1916 with the change of trip styles and Jan 1st 1924, as listed in Associated instruction manuals.  These are the companies own published serial numbers so I presume they are accurate.  Also assuming that Associated engine production started in July 1909 as per a letter published in the back of a reproduction Associated catalog that I own that is dated Feb 1st 1913 and states:

Gentlemen:  In response to yours, I beg to state that I have been handling the Associated Manufacturers Co. line of engines for the last three years and a half, ever since the Chore Boy engines were first built. During this time I have sold a good many engines having bough them in (train) car lots and local, and that I must say that I have had less trouble with your line of engines than any other line of engines previously handled.  It seems that all I have to do is get them out and they take care of themselves.  I wish you much success for 1913 and if nothing happens, you can count on me for another car the coming fall and oblige.  Yours truly, HA Pasewalk, Studebaker Wagons & Carriages, Norfolk, Nebraska.

Any number of factors may have had an effect on production numbers for a given year such as slow early production and the war in Europe.  But I have decided to not try to make this a complicated table, but only a calculated best guess as to the production year for any given serial number.  If any one out there can think of a better way to devise a serial number/date of manufacture table, I am open to any and all suggestions.  I would also like to mention that as engines wore out, broke or what have you, parts were readily available from the manufacturer and were also interchangeable from engine to like engine.  And because of that, there may very well exist an early brass tagged Hired Man sub base with a goose neck (post 10/1916) improved style trip.  Or even in an extreme case, since the Chore Boy and Hired Man engines shared the same sub base, it is possible to find a water cooled Chore Boy (6 Digit Serial Number starting with a 3) sub base that has been fitted with a Hired Man cylinder jug.  This may lead to confusion of serial number series and an engine owner might think that the Hired man serial numbers start with a 3 when what he or she may very well have is a Chore boy sub base retro fitted with a Hired Man / Hand Cylinder.  I believe it is safe to assume that generally, and I am sure that there are exceptions, All Busy Boy engines are 6 digit and start with a 2 (2xx,xxx), all Johnny Boy engines (Introduced in 1915) start with a 25 (25x,xxx) all air cooled Chore Boy engines are 5 digit starting with a 2 or 3, all water cooled Chore Boy engine serial numbers start with a 3, All Hired Man engine serial numbers start with a 1 and Hired Hand a 15 (15x,xxx), all 3 mule team engine (Introduced in 1915) serial numbers start with a 5, all 4 Mule Team/Farm Hand engine serial number start with a 4, all 6 Mule team engine serial numbers start with a 6, all 8 Mule team/Foreman engine serial numbers start with an 8 and all 12Mule Team serial numbers start with 9.  The only exception is with the Iowa Oversize engines that were re-rated.  For example an Iowa Oversize 6HP engine will have a serial number starting with a 4 because it is actually a 4HP engine that has been modified and re-rated as being 6HP.  Please forgive me for any inaccuracies that I have made and any documentation as to positive engine date of manufacture would be very much appreciated.  I hope this guide helps all of you out there to better date your engines.  Unfortunately, I do not have a production /serial number for Johnny/Busy Boy engines dated jan 1st 1924 so I do not have those numbers broken down in this table.  Any numbers higher than the Jan 1924 numbers would be part of the re-rated Iowa Oversize engine line.

Early in my deciphering of numbers for the Hired Man series of engines, I had determined that the serial number for the build date of Jan 1st 1911 would be about 106325.  Well, recently discovered evidence has changed that theory since I have found a Hired Man engine, serial number 104777, with the "patent dated" push rod.  Some earlier Hired Man engines I have seen have the Jan 3rd 1911 patent date stamped on the top of the push rod.  Since 104777 was certainly built after the issuance of the patent, this would date this engine to 1911, not 1910 as I previously thought.  So I have adjusted the Jan 1st 1911 date to 104500 which I feel is a more accurate number by which to date with.  And also since I have collected more photos of engines to verify trip style changes according to serial number, I have adjusted the serial number list to reflect the trip change according to date which I judge it to be about Oct 1st. 1916.

Update Feb '07 I recently was able to aquire an original Associated invoice dated October 24th 1928. The invoice listed a Chore Boy engine serial number 346855. So now I have been able to extend the water cooled Chore Boy engine dates to Jan 1st 1929. I hope this helps alot of people!

Hopefully, one day when I am old and grey, this list will be a very accurate engine dating tool.

Year of

Engine

1 1/2 HP Busy Boy 1 1/2 HP Johnny Boy 1 3/4 HP

Chore Boy

Air Cooled

1 3/4 HP

Chore Boy

Water Cooled

2 1/4 HP

Hired Hand

Air Cooled

2 1/4 HP

Hired Man

Water Cooled

3 HP Mule

Team

4 HP Mule

Team

6 HP Mule

Team

8 HP Mule

Team

12 HP Mule

Team

18 HP Mule

Team

22 HP

Twin Cyl

1/2HP

Colt

June 1909 200001 N/A 30001 300001 150000 100001 N/A 400001 600001 800001 900001 ? ? ?
Jan 1st 1910 N/A 30244 301310 150441 102108 N/A 400512 600316 800097 900052
Jan 1st 1911 N/A 30731 303930 151323 104500 N/A 401537 601580 800290 900156
Jan 1st 1912 N/A 31219 306551 152204 109427 N/A 402562 602844 800483 900261
Jan 1st 1913 N/A 31706 309172 153086 114354 N/A 403587 604107 800676 900366
Jan 1st 1914 N/A 32194 311793 153968 119281 N/A 404612 606635 800869 900471
Jan 1st 1915 250001 32682 314413 154849 124208 500001 405637 607899 801062 900576
Jan 1st 1916 33169 317034 155732 129135 501416 406663 607899 801255 900681
Year of

Engine

1 1/2 HP Busy Boy 1 1/2 HP Johnny Boy 1 3/4 HP

Chore Boy

Air Cooled

1 3/4 HP

Chore Boy

Water Cooled

2 1/4 HP

Hired Hand

Air Cooled

2 1/4 HP

Hired Man

Water Cooled

3 HP Mule

Team

4 HP Mule

Team

6 HP Mule

Team

8 HP Mule

Team

12 HP Mule

Team

18 HP Mule

Team

22 HP

Twin Cyl

1/2HP

Colt

Jan 1st 1917 33657 319655 156452 133462 502833 407688 609023 801449 900786
Jan 1st 1918 34144 322276 156687 135989 504250 408713 609450 801642 900890
Jan 1st 1919 34632 324896 156922 138515 505667 409738 609877 801835 900995
Jan 1st 1920 35120 327517 157158 141042 507083 410763 610303 802028 901100
Jan 1st 1921 35607 330138 157393 143569 508500 411789 610729 802221 901205
Jan 1st 1922 36095 332759 157629 146096 509917 412814 611156 802414 901310
Jan 1st 1923 36582 335379 157865 148623 511333 413839 611583 802607 901415
Jan 1st 1924 37070 338001 158100 161150 512750 414865 612010 802800 901520
Year of

Engine

1 1/2 HP Busy Boy 1 1/2 HP Johnny Boy 1 3/4 HP

Chore Boy

Air Cooled

1 3/4 HP

Chore Boy

Water Cooled

2 1/4 HP

Hired Hand

Air Cooled

2 1/4 HP

Hired Man

Water Cooled

3 HP Mule

Team

4 HP Mule

Team

6 HP Mule

Team

8 HP Mule

Team

12 HP Mule

Team

18 HP Mule

Team

22 HP

Twin Cyl

1/2HP

Colt

Jan 1st 1925 339833
Jan 1st 1926 341665
Jan 1st 1927 343496
Jan 1st 1928 345328
Jan 1st 1929 347160

Note: The jury is still out on the WC Hired Man and AC Hired Hand engines.  Hired Hand serial numbers start at 150000 and I don't know where they stop so I don't know where Hired Man picks back up.  The 01/01/1924 serial number for the Hired Man is 161150 and for the Hired Hand is 158100.  Also the late 1916 trip style change serial number for the Hired Hand is 156393, for the Hired Man is 132830.  I still need more information to make a better decision on these engines. Update!!!  I have found water cooled engine number 160021 so it would seem the 150000 to 159999 block was exclusive to the Hired Hand and water cooled engines picked back up at 160000.  Until I find an air cooled engine numbered in the 16xxxx number range to tell me otherwise, I will adjust the serial number dating list accordingly!  I believe the Hired Hand was greatly out sold by the AC Chore Boy and very few original, two bolt magneto, Hired Hand engines exist.

The following table was created from information taken directly from an original parts and repair list printed by Associated Manufacturers Co. in January 1927 for AMANCO engine owners in Great Britain.   This includes all engines both Regular and Iowa Oversize.  The reason for the table was to show what type trip was used according to certain hammer stop styles and positions used on various styles of igniters originally installed on Associated engines.  Each of the three groups shown below: Straight trip, No Cam, Cam On Trip Rod and New Style Trip had a different hammer stop or position on the moving electrode in the igniter.  There was also another style represented for paraffin engines (Throttle governed kerosene) which was merely the igniter hammer stop for the new improved G 340 "Goose Neck" in the "points closed" position, which leads me to believe that all TG engines were powered by magneto (No battery models) and they all date to after the introduction of the improved trip (No straight trip TG engines).
Trip styles According To Serial Number
Engine Size / Type Straight trip, No Cam

Cam On Trip Rod

New Style Trip Introduced
1 1/2 HP WC

All Thru 259967

None

Starting 259967

1 3/4 HP AC

All Thru 34713

None

Starting 34713

1 3/4 HP WC

All Thru 317151

None

Starting 317151

2 1/4 HP AC

All Thru 156393

None

Starting 156393

2 1/4 HP WC

All Thru 132830

None

Starting 132830

3 HP

None

500001 Thru 502856

Starting 502857

4 HP

All Thru 405362

405362 thru 408526

Starting 408527

6 HP

All Thru 606668

606668 Thru 608951

Starting 608952

8 HP

All Thru 800607

800607 Thru 801358

Starting 801359

12 HP

All Thru 900641

900641 Thru 900995

Starting 900996

Another great thing about this table is that it helps to nail down production dates even more. I have the Jan 1st 1924 serial numbers and now also the serial number of the change to the Goose Neck style trip, which to the best of my knowledge occurred some time in late 1916 so I will be adjusting my serial number dating chart accordingly.  

Click HERE for an Associated "Photo" Serial Number Data Base of serial numbers that I have collected.  You can click on each serial number to see each engine and see the characteristics of each engine.