Model differences

Yes

No

Yes

No

No

Yes

Yes

3 shallower vertical ribs

Most had 3 deeper vertical ribs plus additional diagonal rib running rearward from cylinder base

Very late had horizontal webbing

Horizontal webbing

80 mm

83 mm

70 mm

78 mm

703.717 cc

757.486 cc

844.05 cc

4, 3 above wrist pin, 1 below

4, all above wrist pin

3, all above wrist pin

38 mm intake and 34 mm exhaust

40 mm intake and 35 mm exhaust

Single

Dual

9:1

9.2:1

6000

6500

50

60

64

No boss for future exhaust studs

Early models had no boss for future exhaust studs; later models had a boss for later exhaust studs

Most had no boss for future exhaust studs; Some had a boss for later exhaust studs

One piece design with o-ring

Early models had one piece design with o-ring; later models had two piece design with crush washer

Two piece design with crush washer

Valve guide casting is proud of the top of the cylinder head.

Valve guide casting is level with the top of the cylinder head.

Early models had Moto Guzzi printed below raised area, no ridge on raised area, longer hex-head securing bolts

Later models had Moto Guzzi printed on raised area, no ridge on raised area, shorter allen-head securing bolts

Moto Guzzi printed on raised area, no ridge on raised area, shorter allen-head securing bolts

Early models had Moto Guzzi printed on raised area, no ridge on raised area, shorter allen-head securing bolts

Later models had Moto Guzzi printed on raised area, ridge on raised area, shorter allen-head securing bolts. There were two versions of this valve cover, one style appeared completely shiny while the other style appeared rough with only the raised area shiny. It is believed the shine was not the result of polishing, but rather the result of the manufacturing process.

4.5 gallon

early models had 4.5 gallon

late models had 5.84 gallon

5.84 gallon

Petcocks positioned forward

Early models had petcocks positioned forward

Late models had petcocks positioned rearward

Petcocks positioned rearward

Narrow tunnel

Early models had narrow tunnel

Late models had wider tunnel

Wider tunnel

Cap with lever, lever secured via special boss on tank

Early civilian models had cap with lever, lever secured via special boss on tank

Later civilian models had a cap with a lever, lever secure via ring and groove on neck

Police models had a screw-on cap, taller neck

Push button release style, like was fitted to the 850 T

screw-on cap, taller neck

Civilian models had a cap with a lever, lever secured via ring and groove on neck

Police models had a screw-on cap, taller neck

Screw-on cap, taller neck

most had twin leading shoe

some very late models had four leading shoe (circa 1977)

twin leading shoe

most had twin leading shoe

some in 1973 had four leading shoe

late 1973 and 1974 had single disk

Early models were fit with a two leading shoe front brake. These models used fork lowers with a single retainer for the brake plate (on the left fork lower). These early fork lowers only used an axle pinch bolt on the left fork lower. The right fork lower did not have a pinch bolt for the axle.

Very late models (circa 1977) were fit with four leading shoe front brakes. These models used fork lowers with a retainer on each side for the the pair of brake plates.

Some models were fit with a two leading shoe front brake. These models used fork lowers with a single retainer for the brake plate (on the left fork lower). These fork lowers used an axle pinch bolt on both the left and right fork lowers.

Some models were fit with four leading shoe front brakes. These models used fork lowers with a retainer on each side for the the pair of brake plates (a right side fork lower from a two leading shoe front brake is identical in all other respects). These fork lowers used an axle pinch bolt on both the left and right fork lowers.

Some models were fit with a two leading shoe front brake. These models used fork lowers with a single retainer for the brake plate (on the left fork lower). These fork lowers used an axle pinch bolt on both the left and right fork lowers.

Some models were fit with four leading shoe front brakes. These models used fork lowers with a retainer on each side for the the pair of brake plates (a right side fork lower from a two leading shoe front brake is identical in all other respects). These fork lowers used an axle pinch bolt on both the left and right fork lowers.

Some models were fit with single disc brake. These models used entirely different forks with completely different components.

27°

56.94 mm

81.94 mm

90 mm

70 mm

Information from Gerhard Ziesemann:

I can assure you there is a 3rd type of triple trees with an inclined steering tube. Unfortunately I don't have a pic of that although (or because) I ride a set of these on my sidecar outfit. The only pics to show the three versions I have are of their upper ends with different positions for the steering tube.

Thanks to Patrick Buss for posting these photos on Facebook. I believe the part number for the matching lower triple tree is MG# 12494270.

4 speed

5 speed

1:2.230

1:1.333

1:0.954

1:0.750

1:2.000

1:1.388

1:1.047

1:0.869

1:0.750

Smooth

Ribbed

Earliest all straight cut, middle first straight cut/second-fourth helically cut, latest all helically cut

All helically cut

Larger overall diameter and stepped down where it interfaces with the inner body of the bearing.

Smaller overall diameter and not stepped down.

Smaller overall diameter and not stepped down.

8/37

8/35

8/37

Star burst, polished

Star burst, polished

very late may have had the deeper sump, unpolished

Deeper sump, unpolished

1:14.180

1:8.473

1:6.063

1:4.768

1:13.413

1:8.015

1:5.735

1:4.510

1:11.424

1:7.929

1:5.980

1:4.964

1:4.284

Dellorto SS1 29mm

later models had an intake liner to increase air flow velocity

Dellorto VHB 29mm

Dellorto VHB 29mm

Some were fitted with Amal 930 carburetors while the Dellorto factory was on strike.

Smooth polished aluminum band

Early models had smooth polished aluminum band

Later models had steel bands perpendicular to the carb body

Steel bands perpendicular to the carb body

Most had heel-toe, few had toe only

Heel-toe

Right side, had a different bend to clear the swing arm nut

Left side

Aluminum

Chrome plated steel

Shaft at 12 o'clock, shoe pivot doubles as tie rod attachment point

Early had shaft at 12 o'clock, shoe pivot doubles as tie rod attachment point

Later had shaft at 3 o'clock

Shaft at 3 o'clock

Left side

Right side

1 up, 3 down

1 up, 4 down

Deep shell

Shallow shell

Very early models used an entirely unique tail light which is exceedingly rare.

Later models had additional horizontal mount to the frame, round lens

Early models had additional horizontal mount to the frame, round lens

Later models lacked additional mount, round lens

Early models lacked additional mount, round lens

Later models had a rectangular lens

Civilian models only had a speedometer See civilian and police variations here

Early civilian models only had a speedometer; later civilian models had speedometer and tachometer See civilian and police variations here

Civilian models had speedometer and tachometer See civilian and police variations here

Narrow, non louvered

Early models had narrow, non louvered; later models had wider, louvered

Wider, louvered

Knobs

Early models had knobs

Later models had locks

Locks

Magneti Marelli

Early models had Magneti Marelli; later models had Bosch

Bosch

Across the frame

In line with frame

Narrower backbone (later tank will fit on earlier frame, but not vice versa)

Wider backbone

Siren mount (mechanical sirens had different mounts than electrical - not sure of difference???), stronger gusset plate for seat, gusset plate drilled for rear crash bars, dimple in rear fender mount at the rearmost part of the frame

Magneti Marelli

Early models had Magneti Marelli, later models had Bosch

Bosch

Two individual metal plates (most painted, there is some debate as to whether or not some were chromed)

Early models had two individual metal plates (most painted, there is some debate as to whether or not some were chromed)

Later models had a single black plastic cover

Single black plastic cover

Magneti Marelli

Early models had Magneti Marelli; later models had Bosch

Bosch

Magneti Marelli

Early models had Magneti Marelli; later models had Bosch

Bosch

Short feet, deployment arm only on one side

Early models had short feet, deployment arm only on one side; later models had long curved feet, deployment arm on both sides

Long curved feet, deployment arm on both sides

None

Front and rear

None

Early models had none; later models has reflectors with wide chrome trim; some very late models had reflectors with very narrow trim

Early models had reflectors with wide chrome trim; later models had reflectors with very narrow trim

Shorter

Shorter for all drum brake models. Disc brake models are longer.

Aluminum cap on the back end of the swing arm...just before the rear drive

Boss that could be drilled for aluminum cap

No boss.

Smooth lever with a perch that angled toward the handlebar

Early models used a smooth lever with a perch that angled toward the handlebar

Later models used a finger-grooved lever with a perch that was more square to the handlebar

Finger-grooved lever with a perch that was more square to the handlebar

Models with 4 leading shoe front brakes used a finger-grooved lever with a special adapter to connect both front brake cables

Early models had a black plastic inner cover to hide the rod

Later models used a chrome steel cover to hide the rod

Early models used a chrome steel cover to hide the rod

Later models had a black plastic inner cover to hide the rod

All used a black plastic inner cover to hide the rod

Dual seat.

If used in police service, a solo seat was likely fitted.

Dual seat.

If used in police service, a solo seat was likely fitted.

Dual seat.

If used in police service, a solo seat was likely fitted.

Dual seat.

If used in police service, a solo seat was likely fitted.

Buddy seat.

Dual seat.

If used in police service, a solo seat was likely fitted.

Solo seat.

Foot pegs.

Foot pegs.

If used in police service, footboards were likely fitted.

Foot pegs.

If used in police service, footboards were likely fitted.

Foot pegs.

If used in police service, footboards were likely fitted.

Footboards.

Foot pegs.

If used in police service, footboards were likely fitted.

Footboards.