Indian Serial Numbers

OTC Resource Library

 
Indian Serial Number Data
Year Model Eng. Number Cyl. H.P Bore Stroke Frame Number Notes
1953 353 CS61001-CS62500+ 2       CS61001-CS62500+ last batch of 53's where a large sequence of serials were skipped
1953 353 CS6501-CS6999 2       CS6501-CS6999 'Chief' 53, serials above 6500  accepted as 53 if registration supports.
1952 352 CS6001-CS6500 2       CS6001-CS6500 'Chief' 52,  up to 6500 whether '52 or '53 may depend on registration?
1952 ? BB1001T-up 2       B1001T-up 'Warrior TT', last model year
1952 ? CS4001-up 2       CS4001-up 'Warrior', last model year, Warrior Patrols (3 wheeler for Police/FD)
1951 351 C4001-C4500 2       C4001-C4500 'Chief' 80ci, the last of the eighty's without yr confusion!
1951 651? FEA101-? 2       FEA101-? ''Dispatch Tow' Scout, NYC Fire Dept Only?, note 14
1951 ? B1001T- 2       B1001T- 'Warrior TT', frame sequence continues thru '52
1951 ? B101-up 2       B101-up 'Warrior'
1950 350 C2001-C2500 2       C2001-C2500 'Chief' 80ci, 2nd series, #'s changed, C2441-C2500 to PDNYC Police
1950 350 CEJ1001-CEJ1500 2       3501001-3501500 'Chief' 80ci (1320cc), first year for  telescopic forks, 1st series
1950 ? BEJ1001-up 2       2501001T- 'Warrior TT', 30.50ci(500cc)
1950 ? BEJ101-up 2       250101-up 'Warrior', 30.50ci(500cc)
1950 250 BBEJ1001-up 2       22501001-up Scout', last model year
1950 150 AAEJ1001-up 1       11501001-up Arrow', last model year
1949 349 CDI1001-up 2       3491001-up Chief, very limited production, serials inflated
1949 249 BDI101-up 2       249101-up Scout', 26ci, (440cc), first vertical twin
1949 149 ADI101-up 1       149101-up Arrow', 13ci, (220cc), first vertical single
1948 348 CDH101-up 2       348101-up Chief', new frame, new oil pump etc
1948 648 FDH101-up150 2       648101-150 45" Daytona 'big base' Scout. note 13
1947 347 CDG101-up 2       347101-up 'Chief', no other models
1946 346 CDF101-up 2       346101-up 'Chief', new girder forks, no other models
1945 345 CDE101-up 2       345101-up 'Chief' limited production,
1944 344 CDD101-up 2       344101-up 'Chief', no other models, all military?
1943 343 CDC101-up 2       343101-up 'Chief', very limited civilian production, last of 741's, high serials
1942 442 DDB101-up 4       442101-up Indian 4, the last year of the 4ours..
1942 342 CDB101-up 2       342101-up 'Chief', 74ci
1942 642 FDB101-up 2       642101-up 45" 'Sport Scout', last year of the SS/SSDT, Daytona in '48
1942 542 EDB101-up 2       542101-up 30.50ci 'Junior Scout'
1941 441 DDA101-up 4       441101-up Indian 4, 78ci
1941 341 CDA101-up 2       341101-up 'Chief', 74ci
1941 841 HDA101-up 2       841101-up Military, 841, 45ci transverse, shaft drive
1941 641 FDA101-up 2       641101-up 45" 'Sport Scout' and DT's
1941 741 GDA101-up 2       741101-up Military 741(b) lightweight 30.50ci note 6 and note 18.
1941 541 EDA101-up 2       541101-up 30.50ci 'Junior Scout'
1940 440 DDO101-up 4       440101-up Indian 4, 78ci
1940 340 CAV101-up 2       CAV101-up CAV=Continental Army Vehicle (aka Military Chief, Canadian)
1940 340 CDO101-up 2       340101-up 'Chief', incl Military, except Canada
1940 640 FDO101-up 2       640101-up 45" 'Sport Scout'  and Military 640 Scouts note 6 and note 18.
1940 540 EDO101-up 2       540101-up 30.50ci 'Scout Pony' renamed 'Thirty-Fifty'
1939 439 DCI101-up 4       439101-up Indian 4
1939 339 CCI101-up 2       339101-up 'Chief' 74ci
1939 639 FCI101-up 2       639101-up 45" 'Sport Scout' and Dispatch Tows (DT)
1939 539 ECI101-up 2       539101-up 30.50ci 'Junior Scout'
1938 438 DCH101-up 4       438101-up Indian 4, 78ci
1938 338 CCH101-up 2       338101-up 'Chief' 74ci
1938 638 FCH101-up 2       638101-up 45" 'Sport Scout' and Dispatch Tows
1938 538 ECH101-up 2       538101-up 30.50ci 'Junior Scout'
1937 437 DCG101-up 4       437101-up Indian 4, 78ci
1937 337 CCG101-up 2       337101-up 'Chief'74ci
1937 637 FCG101-up 2       637101-up 45" 'Sport Scout' and Dispatch Tows
1937 237 BCG101-up 2       237101-up 45" Std 'Scout' last model year
1937 537 ECG101-up 2       537101-up 30.50ci 'Junior Scout' renamed 'Scout Pony'
1936 436 DCF101-up 4       436101-up Indian 4, 78ci
1936 336 CCF101-up 2       336101-up 'Chief',74ci
1936 636 FCF101-up 2       636101-up 45" 'Sport Scout' and Dispatch Tows
1936 236 BCF101-up 2       236101-up 45" Std 'Scout'
1936 536 ECF101-up 2       536101-up 30.50ci 'Junior Scout'
1935 435 DCE101-up 4       435101-up Indian 4, 78ci
1935 335 CCE101-up 2       335101-up 'Chief' 74ci
1935 635 FCE101-up 2       635101-up 45" 'Sport Scout' and Dispatch Tows note 14
1935 235 BCE101-up 2       235101-up 45" Std 'Scout'
1935 535 ECE101-up 2       535101-up 30.50ci 'Junior Scout'
1934 434 DCD101-up 4       434101-up Indian 4, 78ci
1934 334 CCD101-up 2       334101-up 'Chief', 74ci
1934 634 FCD101-up 2       634101-up 45" 'Sport Scout', 1st yr with new keystone frame
1934 234 BCD101-up 2       234101-up 45" Std 'Scout' (still chief frame]
1934 534 ECD101-up 2 5.0     534101-up 30.50ci 'Junior Scout'
1933 433 DCC101-up 4       433101-up Indian 4, 78ci (1278cc)
1933 333 CCC101-up 2       333101-up 'Chief' 74ci
1933 633 FCC101-up 2       633101-up 1yr only 45ci 'Motoplane' (in Jr Scout frame)
1933 233 BCC101-up 2       233101-up 45" Std 'Scout'
1933 533 ECC101-up 2 5.0     533101-up 30.50ci 'Junior Scout'
1932 403 DOC101-up 4       403101-up Indian 4, 78ci
1932 EOC/503 EOC101-up 2 5.0 2 1/2 3 1/16 503101-up 'Junior' or 'Pony' Scouts begin, 30.5ci (500cc) 101 mo end
1932 COC/303 COC101-up 2 8.5 3 1/4 4 7/16 303101-up Chief ,74"
1932 BOC/203 BOC101-up 2 6.61 2 7/8 3 1/2  203101-up Std 'Scout' 45" in Chief frame,
1931 HEP/302 EH1536-up 2 8.45 3 1/4 4 7/16  H1410-up Chief, 74"
1931 GP/101 EGP3081-up 2 6.61 2 7/8 3 1/2 G4050-up 101 Scout 45", also first service car. [last year]
1931 G/101 EG925-up 2 6.05 2 3/4 3 3/16  S1344-up 101 Scout 37", frame numbers continue note 9
1931  402 EA1510-up 4 12.10 2 3/4 3 1/4 A 982-up Indian 4, sequence continues to 11/1/31
1930 HEP/302 EH100-EH1535 2 8.45 3 1/4 4 7/16  -none- Chief 74", sequence continues to 11/1/31
1930 GP/101 EGP100-EGP3080 2 6.61     -none- 101 Scout 45" ,sequence continues 11/1/31
1930 G/101 EG100-EG924 2 6.05     none-SI322 note 9 101 Scout 37", continues to 11/1/31, late '30 frame no's commence
1930  402 EA776-EA1509 4 12.10 2 3/4 3 1/4  -none- Indian 4, sequence continues to 11/1/31
1929 GEP/101 DGP4318-up 2 6.61     -none- 45" 101 Scout
1929 GE/101 DG2638-up 2 6.05     -none- 37" 101 Scout
1929 402 EA100-EAXXX 4 12.10     -none- Indian 4, after 6/1/29 changes to EA series, which lasts till '31
1929 402 DA701-DAXXX 4 12.10     -none- Indian 4. up to 6/1/29 then changes to EA100 and up
1929 HEP/301 CH2225- 2 8.45 3 1/4 4 7/16 -none- 'Chief' 74ci, CH numbers continue to 11/12/29
1928 GEP/101 DGP100-DGP4317 2 6.61     -none- 45" 101 Scout changeover yr from sf scout, mostly assumed '29
1928 GE/101 DG100-DG2637 2 6.05     -none- 37" 101 Scout changeover fm short frame (sf) scout assumed '29
1928 -none- CZ100- 2 7.81 3 1/8   -none- 'Chief' 61ci,[last yr]
1928 LE/201 CL100- 1 3.03     -none- 'Prince'  21ci [last yr]
1928 -none-? CH100-CH2224 2 8.45 3 1/4 4 7/16 -none- 'Big Chief' 74ci, to 3/15/28 then model change to HEP/301
1928 -none- CGP1762- 2 6.61     -none- 101 Scout 45"  change to 45" 101?note 7
1928 -none- CGP100-CGP-1761 2 6.61     -none- Scout 45" to 3/15/28  change to 45" 101? CGP444+ note 5
1928 -none- CG2385- 2 6.05     -none- 101 Scout 37" to 3/15/28 then change to 37" 101.
1928 -none- CG100-CG2384 2 6.05     -none- Scout 37" to 3/15/28 then change to 37" 101. note 7
1928 402 DA100-DA700 4 12.10     -none- Ace name dropped, model added, serial CA-DA change 6/1/29
1928

 Ace

CA100-CAXXX 4 12.10     -none- Indian 'Ace' to 8/1/28, DA101-DA700 are also 1928. note 10
1927 Ace VF100-up 4 12.10     -none- First Indian 'Ace' 4 cyl,78ci, and poss E1100  up note 11
1927 -none- BZ100-up 2 7.81 3 1/8 3 31/32 -none- 'Chief' 61ci(1000cc)
1927 -none- BL100-up 2 3.03     -none- 'Prince' 21ci
1927 -none- BH100-up 2 8.45     -none- 'Big Chief" 74ci
1927 -none- BGP100-up 2 6.61     -none- Scout' 45ci(750cc)
1927 -none- BG100-up 2 6.05     -none- 'Scout' 37ci (600cc), last pedestal eng mounts before though-bolt
1926 -none- AZ100-up 2 7.81     -none- 'Chief' 61ci
1926 -none- AL100-up 1 3.03     -none- 'Prince' 21ci
1926 -none- AH1180 only 2 ??     -none- 'Big Chief' 80ci, prototype, 1 only?
1926 -none- AH100-up 2 9     -none- 'Big Chief' 74ci
1926 -none- AG100-up 2 5     -none- 'Scout' 37ci
1925 Model Y 90Y001-up 2 9     -none- 'Big Chief' 74ci
1925 Model Y 80Y001-up 2 8     -none- 'Chief' 61ci
1925 Model Y 50Y001-up 2 5     -none- 'Scout' 37ci
1925 Model Y 30Y001-up 1 2.75     -none- 'Prince' 21ci (350cc) single, [first model yr]
1924 Model X 90X001-up 2 9     -none- 'Big Chief' 74ci
1924 Model X 80X001-up 2 8     -none- 'Chief' 61ci
1924 Model X 70X001-up 2 7     -none- 'Standard' ,last year for the former Powerplus
1924 Model X 50X001-up 2 5     -none- 'Scout' 37ci
1923 Model V 90V001-up 2 9     -none- 'Big Chief' 74ci(1200cc)
1923 Model V 80V001-up 2 7     -none- 'Chief' 61ci
1923 Model V 70V001 2 7     -none- 'Standard' (pplus) 61ci note 12
1923 Model NP VP001-up 2 8     -none- 'Powerplus' 72ci renamed 'Standard' note 12
1923 Model V 50V001-up 2 5     -none- 'Scout' 37ci
1922 Model T 80T001-up 2 7     -none- 'Chief' 61ci (1000cc) first year, tho sold oct '21
1922 Model NP TP001-up 2 8     -none- 'Powerplus' 72ci big valve note 12
1922 Model T 70T001-up  2 7     -none- 'Powerplus' 61ci
1922 Model T 50T001-up 2 5     -none- 'Scout' 37ci
1921 Model NP SP001-up 2 8     -none- 'Powerplus' 72ci big valve note 12
1921 Model S 70S001-up 2 7     -none- 'Powerplus' 61ci
1921 Model S 50S001-up 2 5     -none- 'Scout' 37ci
1920 Model NP RP001-up 2 8     -none- 'Powerplus' 72ci big valve note 12
1920 Model N 70R001-up 2 7     -none- 'Powerplus' 61ci
1920 Model R 50R001-up 2 5     -none- 'Scout'  37ci - [first model year]
1919 Model MP MP001-up 2 8     -none- 'Powerplus'  72ci, 8hp, big valve
1919 Model M 70M001-up 2 7     -none- 'PowerPlus', 61ci, 7hp, 2nd series
1919 Model M 40M001-up 1 4     -none- 'PowerPlus', 30.5ci single,loop frame,
1919 Model M 30M001-up 2 2.5     -none- 2 hp, loop frame, twin cyl, ci=?
1918 Model K KRX001-up 2 ??     -none- ?hp, loop frame, 2nd series, special?
1918 Model N 70K001-up 2 7     -none- 'Powerplus' 61ci
1918 Model B 50K001-up 2 4     -none- Little Twin 42ci, Hedstrom f-head motor note 17
1918 Model W 40K001-up 1 4     -none- 'PowerPlus', 33.5ci single, commercial
1918 Model 0 30K001-up 2 2.75     -none- Light Twin 15.7ci,(Horizontally opposed motor)
1917 Model J RX001-up 2 7     -none- 7hp, loop frame,  special?
1917 Model N 70J001-up 2 7     -none- 'Powerplus' 2nd model year for 61ci (1000cc)
1917 Model B 50J001-up 2 4     -none- Little Twin 42ci, Hedstrom f-head motor note 17
1917 Model W 40J001-up 1 4     -none- 'PowerPlus', single,4hp, 33.5ci commercial model
1917 Model O 30J001-up 2 2.75     -none- Light Twin 15.7ci, (Horizontally opposed motor)
1916 Model G 70H001-up 2 7     -none- 'Powerplus' first model year for L-head 61ci with cradle spring frame.
1916 Model F 70H001-up 2 7 3 1/8 3 31/32 -none- 'Powerplus' first model year for L-head 61ci model with rigid frame.
1916 Model B 50H001-up 2 5     -none- Little Twin 42ci, Hedstrom f-head motor note 17
1916 Model K 20H001-up 1 2.5 3 1/8  3 3/32  -none- Featherweight" 2 hp,  loop frame,two stroke
1915 Model G 70G001-up 2 7 3 1/4  3 43/64 -none- 7hp, loop frame, Big Twin, 1st series 6ci, {B}
1915 Model G 50G001-up 2 4 2 3/4  3 1/2  -none- Little Twin, 2nd series, 7hp, loop fr,  note 4, chrome vanadium frames!{B}
1915 Model E 40G001-up 2 4 3 1/4 3 43/64 -none- Little Twin 42ci, Hedstrom f-head motor note 17
1914 Model F 70F001-up 2 7 3 1/4 3 43/64 -none- 7hp, loop frame, twin, 1st series, Hendee electric starter offered!
1914 Model F 40F001-up 1 4 3 1/4 3 43/64 -none- 4hp, loop frame, single, electrics fitted!
1913 Model E 70E001-up 2 7 3 1/4 3 43/64 -none- 7hp, loop frame, twin, yes & 80E0001 up as 32,000+ were built. note 4 and note 8
1913 Model E 40E001-up 1 4 3 1/4 3 43/64 -none- 4hp, loop frame, single, cradle spring rear frame, rigid still avail.
1912 Model D 70D001-up 2 7 3 1/4 3 43/64 -none- 7hp, loop frame, twin, rigid rear only.
1912 Model D 40D001-up 1 4 3 1/4 3 43/64 -none- 4hp, loop frame, single, first for kick starter!
1911 Model C 70C001-up 2 7 3 1/4 3 43/64 -none- 7hp, loop frame, 2nd series, improved carb jets!
1911 Model C 40C001-up 1 4 3 1/4 3 43/64 -none- 4hp, loop frame,  2nd series
1911 Model C 20C001-up 2 5 3 1/4 3 43/64 -none- 5hp, loop frame, twin, 1st series
1911 Model C 1C001-up 1 2.75 3 1/4 3 43/64 -none- 2 hp, loop fr. sgle, 1st series, int and ext brakes, knock out rear axle!
1910 Model B 70B001-up 2 7 3 1/4 3 43/64 -none- 7hp, loop frame, 2nd series
1910 Model B 40B001-up 1 4 3 1/4 3 43/64 -none- 4hp, loop frame, 2nd series, footboards and front axles fitted!
1910 Model B 20B001-up 2 5 2 3/4 3 1/4 -none- 5hp, loop frame, twin
1910 Model B 1B01-up 1 2.75 2 3/4 3 1/4 -none- 2 hp, loop fr. sgle, 1st series, mech. oilers  multidisc clutch fitted!
1909 -none- IOA001-up 1 3.5     -none- 3 hp, loop frame, single, 1st series, 26.96ci (440cc)
1909 -none- IA01-up 1 2.75     -none- 2 hp, loop frame, 19.30ci (315cc)
1909 -none- 70A001-up 2 7     -none- 7hp, loop frame, 2nd series, Big Twin, 61ci (1000cc)
1909 -none- 40A001-up 1 4     -none- 4hp, loop frame, 2nd series, 30.50ci(500cc), hand brake introduced!
1909 -none- 20A001-up 2 5     -none- 5hp, loop frame, twin, 38.61ci(630cc), first 2spd transmission!
1908 -none- T500-T1200 2 5     -none- 5hp, diamond frame
1907 -none- T100-T499 2 3.5     -none- 3 hp, diamond frame, first production v-twin!
1907 -none- 5000-up 1 2.25     -none- 2 hp, diamond frame, first  yr of mechanically operated valves!
1906 -none- 2350-4048 1 2.5     -none- 2 hp, diamond
1905 -none- 1168-2349 1 2.25     -none- 2 hp, diamond frame, also a light weight twin cyl
1904 -none- 621-1167 1 1.75     -none- 1 hp, diamond frame, first yr of spring front and tandem attachment!
1903 -none- 244-620 1 1.75     -none- 1 hp, diamond frame,  first yr of handlebar controls!
1902 -none- 101-243 1 1.75     -none- 1 hp diamond frame,  first chain transmission!
1901 -none- -none- 1 1.75   -none- 1 hp diamond frame 90lbs!!, Indian Carb!


Engine Number Series and Year Decoding
J A B C D E F G H I
0 1 2 3 4 5 6 7 8 9

Frame

Arrow 1xx
Scout/Warrior/TT 2xx
Chief 3xx
1950-1953
Midstream the 1950 Chief serial numbers changed from CEJ to just C on BOTH engines and frames, upsetting the rules as shown in the 1932-1950 table. Early 50's Chiefs were CEJ, late '50 and' 51 Chiefs were  just 'C', and all '52 and '53 Chiefs were 'CS' . When this change happened all vertical twins also had frame numbers matching the engine exactly too. Examples :
Eng# BEJ911, Frame # 250911 is 1950 Warrior.
Eng# B1003, Frame # B1003 is 1951 Warrior.
  A B C D E F G H I
0 1 2 3 4 5 6 7 8 9

Frame

Jr. Scout 5xx
Std Scout, & VT 2xx
Sport Scout, MP 6xx
101 Scout 101
741 (mil) 741
841 (mil) 841
Chief 3xx
Indian 4 4xx

MP=Motoplane (in Jr.Scout frame)
VT=Vertical Twins excl Arrow.

1932-1950
Frame Numbers introduced late 1930 early 1931  See note 9.
Example:we have an unknown motor (or cycle) that's stamped CDF 6403 and a spare frame stamped 441 1089  <work in reverse, i.e. numerals to letters using table or your fingers!>

1st letter is C, this is the series, all Chiefs are 3, Fours are 4 etc (see table left)
2nd letter D is the decade year  4 and the
3rd letter F is the digit year 6

Answers:
Motor is 1946 Chief, Serial# 6403 (6303rd* made!)
Frame is 194 1 Four, Serial# 1089, (989th* made!)   *as first machine started at xxx101
 
In order for a cycle to have 'matching numbers', the frame number must match the engine number and the first three numeric digits of the frame number equal the decoded motor number. i.e. for our example, the frame would have to read 346 6403.  see Frame Numbers.

  A B C D E F
Yr '26 '27 '28 '29 '30 '31

Engine

Prince 21ci L
Scout 37ci G
Scout 45ci GP
Chief 61ci Z
Big Chief 74ci H
Four 1926/7 E
Four 1928-1931 A
1926-1931 
Indian lost the plot for a few years between 1925 and 1933 with their numbering, possibly exacerbated by the 101 series 'no new model years', the Ace acquisition and how to incorporate frame numbers in 1930/31 which I will ignore in this scenario.

Examples:
AH1088 is a 1926 Big Chief, 74ci, serial 1088 
(similarly, AZ1088 would be 1926 61ci)
BGP1055 is a 1927 Scout, 45ci, serial 1055
(similarly, BG1055 would be 1927 Scout 37ci)
EA779 is a 1930 Four,  serial 779
(similarly, BL779 would be 1926 Prince)
Model/hp(Hendee/Indian)
1=
2 hp single
2
= 5hp twin or 2 hp single
3 = 4hp twin or 2 hp twin,
 or  21ci Prince single
4 = 4hp single or 30.5ci Pplus
5 = 7hp twin or Scout 37"
7 7hp twin or 61ci PowerPlus
8 = 8hp twin or  Chief 61ci
9 = Chief 74ci = or 72ci Powerplus

Years     Example

A=1909
B=1910
C=1911
D=1912
E=1913   Ex.3
F=1914
G=1915
H=1916
J=1917
K=1918
M=1919  Ex.2
R=1920
S=1921
T=1922
V=1923
X=1924  Ex.1
Y=1925
 
(I, L, N-Q, U & W  not used.)
also see note 12 for ?Pxxx models (where ?=R,S,T or V)
 1909-1925 hang on it gets a little tougher now!.  
Its a little like an odometer that clocks over in units, tens, hundreds and thousands and tens of thousands. You may find it easier to pay attention to the year first, then look at table and determine the models for that year, see Example 2.

Example 1 - 51X107
Take the engine number 51X107 which breaks down to:
5 is Scout 37", (because of X) then because the second number is not zero (as it would be if serial < 1000)  we add it ( 1000) to the serial 107 making it 1,107,
The X is the year 1924. So it is a 1924 Scout with a engine serial of 1107...
eg.  a serial of 54X155 would be the same model and yr with a serial of  4,155.
similarly, a serial of 67X157 would be the same model and yr with a serial of 17,157.

Example 2 - 72M911  
Take the engine number 72M911 which breaks down to:
'72 equals 7 &2 and  think of this as 2000 (thousandths digit)
The M is the year 1919. The 7 is a 61ci Powerplus (because of  the M) and the remaining 2000 is the thousandths unit of the engine number whereby adding it to 911 gives us 2,911.
So it is a 1919 Indian Powerplus with a engine serial of 2911...
similarly, a serial of 81M177 would be the same model and yr with a serial of 11177.

Example 3 - 86E630   <please see note 8>
Take the engine number  8 6E630 which breaks down to:
 86 equals 7 &10+6,  think of this as 10000 (ten thousandths digit, i.e 70xxx-80xxx), then add this PLUS the 6000 (thousandths) to the 630 it gives us16,630.
The E is the year 1913. The 7 is a 7hp Hendee twin.  So it is a 1913 7hp Twin with a engine serial of 16630...
similarly, a serial of 70E433 would be the same model and yr with a serial of 433.

1902 101-243
1903 244-620
1904 621-1167
1905 1168-2349
1906 2350-4048
1902-1908  
There was no commercial sales in 1901 but numbering began 1902 starting at #101 and remaining in sequence to #4048 until 1906. This gives us an insight into production numbers. From this point till 1909 as the database illustrates, its anyone's guess what someone was dreaming up!
Engine number suffixes
"A letter may be stamped after the engine number (but off to right of boss itself, i.e. on crankcase): these letters are:-
A is for aluminum pistons which were optional over std cast iron pistons in scout 45"in 1928 see note 5
B is for Battery ignition (distributor).  (post 1933, see below note) ...BUT
   - B
was used (briefly) to denote blackout lighting fitted by the factory on mil. cycles during WWII. see note 6
   - B
also designated aluminum piston and/or special clearances for performance and/or sustained speeds on pre '28".
   - B
also designated aluminum piston, chief carb (DLX81?), chief valve springs and chief inlet nipples/manifold used on special factory 101 Scouts.
BM
is for Bonneville Motor.
BY is for Battery (Distributor) ignition on 'Y' motors, i.e.. Y manifolds, trench heads (Ricardo) etc - mostly mid 30's models.
M
is for Magneto ignition.
MY
is for Magneto ignition on 'Y' motors, - rare, mostly mid thirties models.

Frame number locations (also see note 9)
'31 and up rigid frames are on a boss just below the left rear axle slot,
'40 spring frames are on the left rear shock casting above the axle slot,
'41 through '51 are on the lower left  shock mounting ring,
'52 through '53 are on the front face of the right front footboard casting mount.
'49-'52 VT's (Vertical Twins), i.e Scouts, Warriors/ TT's and Arrows, have the frame serial on the front forks.
'34-'42 DT's (Dispatch Tows), i.e 3 wheel Sports Scouts have the frame # under the seat on the frame casting.

Matching Numbers
The practice of re-stamping frames to match engines to make a 'matching number machine ' an vice versa often results in the frame number being exactly the same as the engine number, eg CDF 4321 and CDF 4321. In actual fact the frame would have been stamped, in this case, 346 4321. This is often the single most giveaway as Indian did not match serials on chiefs till mid 1950, watch out for this on ebay!

Production Numbers
Much of this data has been gleamed from Jerry Hatfield.
sc=sidecars,  nr=no records?,  co=chiefs only, ap=approximate

Year Qty Note Year Qty Note Year Qty Note
1901 3 1919 21,500 1937 6,037
1902 143 1920 ? nr 1938 3,650
1903 376 1921 ? nr 1939 3,012
1904 596 1922 ? nr 1940 10,431
1905 1,181 1923 ? nr 1941 8,739
1906 1,698 1924 ? nr 1942 16,647
1907 2,176 1925 ? nr 1943 16,456
1908 3,257 1926 ? nr 1944 17,006
1909 4,771 1927 ? nr 1945 2,070
1910 6,137 1928 ? nr 1946 3,621
1911 9,763 1929 ? nr 1947 11,849
1912 19,500 1930 ? nr 1948-49 9,000 ap
1913 32,000 1931 4,557 1949 ? nr
1914 25,000 1932 2,360 1950 2000+ co,ap
1915 21,000 sc=3,200 1933 1,667 1951 500+ co,ap
1916 22,000 sc=3,700 1934 2,809 1952 500+ co,ap
1917 20,500 1935 3,703 1953 2000+ co,ap
1918 22,000 sc=13,300 1936 5,028  
Extended Notes and Contributions.

1. Introduction. This database is by no means perfect, but as close as we can collectively get it to-date, if you have something to contribute, or query my info Contact Us as this is a collaborative effort. Consternation lies mainly between the dates of March 15th, 1928 and 1st November 1st, 1931, the latter being when frame numbers were introduced and numbering and model numbers were somewhat rationalized.

2.
Several of the serials & dates have been assumed or generalized based on rationalizing conflicting info from each source all of which have differed. Remember model years differ from production years, many new models were offered in the last qtr of the prev year
All dates are of the MM/DD/YY format.

3.
Four valve specials and factory racer motors were not identified and/or recorded.

4. The 1915 parts book also uses letter designation of models;
B is a twin (50 series) with smaller or lighter engine with few parts interchangeable with other twins models C & D,
E model is the single cyl 40G series 

5. Cast iron pistons std on Scout 45 unless motor bears the letter 'A', which uses aluminum pistons, this is from: CGP444 on, i.e. CGP445 A.  see eng# suffixes

6. All Export 741's GDA101 & up were supplied with blackout lighting as standard.
1940 640B's #'s FD01015-FDO1515 and FD02310-FD02636 were also factory fitted with optional kits offered for others.

7. The highest 'CG' number recorded for '28 short frame (std) scouts by the 101 Association is:
CG2384, the highest 45" 'CGP" number is CGP1761, deducting 100 from each should give known numbers produced before the change over to 101.

8. All 09 thru 12 were rigid frames and all 13 were leaf spring front and swing arm rear.  In 1914 and subsequent there were also rigid frame models.
70E1005 would be the same Model 7 (61 CID Twin)  with a SN of 1005.
80E0450 would be the same engine/model with a SN of 10450 (7+1, i.e 1 in front of serial number).

9. A 1930 101 (EG901) has been found with a frame number of SI322. Originally SI344 was recorded as the starting frame number as first used in '31. This proves frame numbers started late '30 not '31. (EG901 is just 24 units serials off a '31 101). We would like to know about any lower frame numbers than SI322 please, until then we will use SI322 a starting reference.

10. The 28 Ace had been listed with serials starting as CA210 up, a reader has said "I was lucky enough last year to find a 100% complete 1928 Indian ACE in Sweden with all the delivery dockets and service history for the first few years, its serial number is CA196"

11. While not Indian (yet!) 1920-1926 Ace Motorcycle serial numbers are included here to give some insight into the numbering before Indian acquired Ace from Michigan
1920 A1000-
1921 A1xxx-?
1922 B3000-
1923 B3xxx-?
1924 D8000-,
1925 no production? or no info? -
1926 E1000-, (poss just E1100 up?)

12. Starting 1920 the 61ci PowerPlus (N and NE) was offered in a larger 72ci capacity named the NP and NEP (electrics) models. These 1178cc models had engine numbers starting with the following:
1920 ="RPxxx", 
1921="SPxxx",
1922="TPxxx" 
1923 ="VPxxx".
These were invariably big valve models, but there was 61" big valve models also that had an enlarged (chief size) exhaust valve. In 1923 Indian renamed the PowerPlus to Standard in order to dispel the myth that the PowerPlus had more power than the Chief.

13. The rear frame # began with 648 followed by a 3 digit #. Such as, 648 106. I used to own the bike Floyd Emde rode at Daytona in '48. I restored it in '78-79 and later sold it to a mid-west collector-dealer. The rear frame on these machines was standard 741 with the addition of a ferrule on either side for the seat spring bolt. To the best of my recollection they started at FDH 101 and went to FDH 150. The rear frames were stamped 648 101 to 648 150.

14. The Sport Scout based three wheel dispatch tows (DT), (previously known as the service car in 1931 in the form of a 101 scout.  later known as traffic car in some configurations). These 1934 to 1942  where offered in many styles and had the standard sports scout engine serial nomenclature, with the following exception:  the frame number is under the seat on the casting where the tubes meet.
This configuration was revived again for the police depts in 1950-1952 in the Indian Patrol which consisted of either 45ci Scout, 80" Chief or 30.5 ci Warrior models.

I had a 1951 (FEA106), a friend has FEA103 & FEA104. A FEA105 is overseas and is a two wheeler, I have pics.  You cant say it was never made because if you wanted special orders they would make it. 103 &  were NYCFD (fire dept) bikes. I sold mine 20 years ago, my friend still has his.

15. I have a listing of factory serial number listings from 1910 to 1931. while the form doesn't have the factory's name on it persay,  the weight and age of the paper, the typeface and layout, plus the mention of Form M801 (Form M779 is a riders manual, M809 is a parts list and so on) leads me to believe it is authentic. Greg

16. "Starting with Motor no. EA580, machines were equipped with all steel clutch, wide transmission gears, single keyway trans shaft
and engine sprocket. Prefix letters AB are used to designate this change".

17. The Model B Little Twin (with 42ci Hedstrom motor), continued to be sold in the UK, Australia, NZ? etc for a number of years after the 1915 cut-off that occurred in the USA.  The 1916 UK sales catalogue states: This model has proved so wonderfully popular during the past year, that we are continuing it on the market.=E2=80=9D  The same model is still listed in the 1918 UK sales catalogue.
..."Earlier this year I purchased a 1917 Indian Model B 'Little Twin' (this is the one with the 680cc (42ci) Hedstrom motor). I have found documentation that these bikes continued to be sold in Australia, New Zealand and the UK right up until 1918. I currently know of 3 such machines a 1916, 17 and 1918 TT Racer-50K130. A number of engines also exist.".

18. I've never found an exact count of how many 1941 Sport Scouts Indian produced. We have a nice unrestored, low-mileage original bought in 1959, very high 1400 serial number. We also have a factory stamped motor in the low 1500's. The military 45 cu in Scouts, even though most were built in 1941, all carried 1940 numbers. FDO, not FDA. The 741's were 1941 Scouts, but due to military contracts, like the 640, 741's were built in 1941, 1942 and 1943, but they all carried GDA numbers. -Robin