Needed to do this for a while, so here is what I have figured out so far. There has been many people along the way that has contributed and a few that has helped set me straight. hahaah.
I don't know how far back this goes , but I know that Murray used a single letter to represent the year since at least 1949. Most of these bikes up until the early 60's had the serial number stamped on the bottom of the bottom bracket. I have seen the letters MOS stamped on most of these. I ASSUME that they stand for Murray of Ohio Supply. This is usually followed by a - and a single letter. That letter will be the year code. After the year code will be a 2 or 3 digit number that stands for the model number. This excludes bikes built for Sears and Gambles(Hiawatha). Sears bikes had a 502 and Gambles bikes had a WG or a WG and a single digit. Sears bikes then had a 2 - 5 digit number afterwards that stood as the model number and was actually used in there catalogs as the part number. Gambles Hiawathas were the same way.
F = 49
G = 50
H = 51
I = 52
J = 53
K = 54
L = 55
M = 56
N = 57
P = 58
R = 59
S = 60
T = 61
U = 62
W = 63
X = 64
Y = 65
In 65 they were changing there serial number style and by then they were on the left rear dropout. Some 65 bikes had an MO5 which stood for Murray of Ohio 1965. After these 3 digits was a 2 or 3 digit model number followed by and X and a 1 or 2 digit number that I will discuss momentarily.
MO5 = 65
MO6 = 66
MO7 = 67
MO8 = 68
In 69, they changed the layout yet again. They dropped the O. They also went to a 4 digit model number.
M9 = 69
M0 = 70
and so on.
This is what I have so far on the X numbers. We need to add to the list as more show up. Ron and I were talking about these numbers recently. We figure that a customer had to order a minimum number of bikes per order to have there own X number. If they didn't order a minimum number of bikes, they possibly shared an X number with a Murray badged bike. Kenny.
X6 or X6? = Otasco
X7 = BF Goodrich
X10 = Westernflyer (Western Auto)
X12 = All Pro (Kmart)
X13 = Murray
X18 = Hiawatha (Gambles)
X25 = Foremost (JC Penneys)
X28 = ?
X43 = Murray
X55 = Murray
X67 = Sportscrest
X69 = Special for 1969 (in 69 only, could have been used other years as a different meaning)
X70 = Special for 1970 (in 70 only, could have been used other years as a different meaning)
X71 = Sportscrest (?) Also Special for 1971 (in 71 only,could have been used other years as different meaning)
X81 = Murray
X82 = Murray
X83 = Might actually be a Sears number??????
X84 = Murray
