Following a request that my friend Enrique made to me in the La Maneta forum, I decided to write a small guide to help those who do not know how the amazing “Montesa parts manuals” work, which make life easier for everyone who uses them. Above all, if we understand them as they were conceived in the factory. Even today I am amazed by the mentality of Pedro Permanyer, at a time when we were far from the rising of computer science in our lives. The system can’t be more logical.
The first thing we should know is that, from the Impala, all Montesa parts have a unique reference formed by three groups of numbers (and sometimes a fourth group). These groups were separated from each other initially with a point, but eventually ended up joining the first two groups into one (I believe that because the point that separated the model and group was not necessary because there were no confusions). These composed references are those that appear in the sections of Montesa, and it is worth understanding how they are generated. Because understanding it will help us enormously to locate parts, know what compatibilities there are between models, etc.
The first number of the three that make up each reference is given by the factory code of the model, which was also used to number each frame and engine. The list-taken in part from the old Rocky Mountain Montesa of my missed friend John Haberbosch-is as follows:
4M post 20.000
Montesa 50 A 1
Cota 25, 25A
Impala Cross 175 (175 Scrambler)
Impala Cross 250 (250 El Diablo)
Ciclo Montesa / Indiana
Cappra 125 MX
Cotas 247 y 248
Texas 250 (Scorpion USA)
Impala Sport (USA)
Enduro 75 L
Mini Montesa (Moped)
Cota 123, 123T
Scorpion 50, 50R
King Scorpion 250
Cappra 360 GP Europe/USA
Cappra 125 VA a VF
Cota 242, 304, 307 y 309
Rapita 50, 50R
Impala 2 125
Cappra 250 Five
King Scorpion Automix 250
Rapita Automix 250
Cappra 360GP, 360DS
Enduro 125 L
Cota 25 C
Cotas 348, 349 y 350
Cappra 250 GP
Enduro 250 todas las versiones.
Cappra 360 GP
Enduro 75 H6 y H7
Cappra 250 MX
Cappra 360 VA a 414 VG
Enduro 360 H6 y H7
Enduro 125 H6 y H7
Cappra 250 VR a VG
In addition to those on this list, there is a "fictitious model" (the 2M, or 02 in the parts lists) that corresponds to the original Impala monoblock engine, from which everything changed at the Montesa factory. This number is very frequent and is maintained until a very late time because even the latest engines inherited many pieces of the original Impala.
The second digit of the part number is given by the "Group" to which the part in question belongs. The list of Groups is the following:
Usually divided into two sheets (I and II) that correspond to frame and fenders and to tank and seat.
Steering and front suspension
Handlebar, seat, grips, throttle and steering axle.
Spares that are part of the fork, except for the triple clamps.
Swinging arm and shock absorbers. Sometimes it includes cutting of the shock absorbers with their manufacturer's own codes.
Wheels and brakes
Tires, rims, hubs, rear sprockets and bearings.
Brake shoes, brake levers, rear brake levers and control cables.
It is usually divided into I and II which correspond respectively to thermodynamic group plus escape and to crankcases.
Flywheel, coils and spark plugs. It usually includes references of the manufacturer of the elements.
Carburetor and air filter, with references of the manufacturers of the elements.
Clutch and primary drive
Includes chain, control cable and sprocket.
Gear sprockets and selection forks.
Lever and internal mechanism.
Selector and shift lever.
Electrical wiring, headlamp and rear lamps. It usually includes cutting of the lighting elements with references from its manufacturer.
Odometer, tools, front plates, etc.
Combining these two tables we already have an idea of how the references work. We will know, for example, that an Enduro 360 frame part will always be a 67.20.XXX (6720.XXX after the loss of the first intermediate point), or that a steering part from a Cota 348 will be a 5130.XXX . We will even learn things about the evolution of the models: for example, when we see the sheet of Cota 348’s tank and see in it the piece 34.20.06201, corresponding to the tank’s badges, we will know that those badges comes from a King Scorpion since its numbers begin with a 3420.
Useful, right? But there is much more. Because Mr. Permanyer sent each dealer a series of ring binders containing the original sections of each of his bikes, arranged in the sequence given above for the Groups. This allowed that when the factory introduced an improvement or a change in the model, an additional sheet was added to know what changes were introduced.
To understand how it works, we’ll discuss the first two pages of a Cota 247 frame. The first one:
The first thing we must look at is the lower area where we are informed that it is a sheet of a Cota 247, corresponding to the Frame I Group (there is a Frame II that is a tank, seat and accessories), and that it applies to the motorcycle from 21M0001 (that is, to the first unit of Cota 247).
The next thing is that we will see a mixture of pieces 21.20.XXX created especially for the model, along with others from different models, such as 33.20.020 (the sidestand spring) that comes from a Cappra 250 (model 33M, as we see in the models table).
Finally, and to them I will refer last, we will see that there are also parts with numbers that start with 0.9X.YYY, which are special cases.
When we turn to the next page of the manual, we will see that we are facing the first modification, which was applied from motorcycle number 500 (21M0500).
And to make our lives easier, Montesa emphasizes the part numbers that have changed in this "Frame Group I", as it happens with the same sidestand spring, which is now a Cappra 250 Five (43M). It’s impossible to make it easier.
Finally, it is necessary to explain the special groups of parts, which we could call "generic". They are the following:
0090.XXYYY Metric screws.
Where XX marks the diameter in millimeters and YYY the length. Thus, a 0090.05022 is a hexagonal screw M5 of 22 mm in length. A “5x22” as they are commonly referred in the supply stores.
0091.XXXXX Special screws.
Where the casuistry is wide and I do not have it very clear. I believe that the denomination comes from the pieces "D91XX" that in the original Impala indicated Withworth measurements. In the last series they were used for countersunk screws (present in Dimensions from 330 and 242), Allen screws, etc. These last denominations are very long, as for example the 0091.0010502032 that indicates an Allen screw 5x20.
Where the XX is the diameter in millimeters, and can include several suffixes to indicate if it is self-blocking, standard, etc. For example, a 0092.08011 is an M8 self-locking nut and a 0092.08030 is an M8 elastic nut.
D92XX Withworth nuts
As far as I know, they were only used in Impala and derived for very specific things. They are the D9206 (1/4 inch) that fixed the saddle to the frame, D9210 (1/8 inch) and D9211 (5/32 inch).
0093.XXXXXX Washers and o-rings.
Where the casuistry is large:
0093.104 to 0093.112 indicate flat washer between M4 and M12
0093.30XXXXX are o-rings, like the 0093.3010015 that are 10x1,5 o-rings.
0093.4XXX indicate cable grommets.
0093.504 to 0093.518 indicate elastic washer between M4 and M18.
0093.7XX and 0093.8XX are spacial washers.
0094.XXXX Balls, bearings and bushes.
X is usually the numbering of the standard bearing model used. Sometimes it uses the suffix C3 to indicate tolerance, as in the crankshaft.
X and Y are usually measured in millimeters as in 0095.0413 which are 4x13 rivets.
0097.XXYY Plugs and fasteners.
X and Y is usually diameter and length.
0098.XYY Elastic rings (Seeger type).
Being the X values 1, 2 and 3 for axis, hole or "type E", and the YY diameter in millimeters. A 098.114 is a seeger for a 14 mm sahft, a 0098.240 is the seeger for a hole of 40 mm, and a 0098.310 is a “type e” seeger for a 10 mm shaft.
Normally X and Y mark internal and external diameter. As a general rule, the thickness is usually 7 mm, with few exceptions that I remember now, and that go to 10.
Sorry for such a heavy text. But I hope it will be of help for those who love Montesas and a good starting point to make your own discoveries.