The motor of an Horex Regina 01

Typ 01.


Motor Typ 01 Bj. 2/53

On the first view, the engine looks not bad for me. Ignition and generator are OK. I can kick the starter and shift the gears. The compression is bad, and after kicking the starter, there was oil on the street. Due to the massive dirt everywhere on the motor, i could not localize where it was comming from.


Motorblock tripartite.

My motor housing (on the picture) is made from three parts. The older HOREX Regina Model has a housing made from four parts.
You can detect a quadripartite motor by the additional parting point on the left side of the vent screw.


"Small motor".

This motor is called "small motor" due to the size of the left cover of the primary drive, which is 45mm thick. Later on, the housing was 55mm thick because there is an additional bearing in the cover.


Housing numbers.

On the front of the motor you will find numberst stamped on each part of the housing. When the motor was produced, the numbers on each part were equal.


Ignition and generator Noris MLZa 6/45/60 re.

On the test-run everything was OK. The centrifugal adjust device for the ignition timing is workung properly.


Carbon brushes.

Also the carbon brushes are in good condition.


Generator -rotor.

The rotor with the collector.


Left shaft.

After removal of the rotor you can see the left part of the crankshaft.



Cover primary drive.

In the cover of the primary drive is only a shaft sealing ring.

On the 55mm wide cover, there is a bearing inside.


Pressure pin clutch.

A misfortune happens when i try to open the screws of the left housing.

To get a lot of pressure on the screwdriver, i place the motor on the right side. At this time the pin was fallen out of the shaft and got wedged. The result you can see here.

Nobody is perfect. Take care in the future....


Primary drive.

The primary drive with clutch and starter after opening the housing..



The ventilation system ejects the overpressure directly into the primary drive on my



On my primary drive there is a duplex-chain, on older motors it is a simpley chain.


Chain tensioner.

The chain tension is controlled by a spring steel sheet. On newer models there is a adjustable chain tensioner.


Coupling disc wheel.

The coupling disc wheel without discs, after opening the screw nut (right-hand thread on my motor).


Clutch body.

The clutch body is fixed on the chain-wheel with six screws.



Chain wheels of primary drive.

On the right wheel, where the clutch body was fixed, you will find six rubber mountings.



Splined shaft.

To remove the chain wheel form the splined shaft i have to use a pull-off tool. Take care about the spring for the kick-starter.
When i have done this the the shaft of the kick-starter gets out an the spring of the kick-starter expands instantly.
So it was not possible to count how many turns i was pretensioned. Also it is a good idea, to make some pictures before starting to disassemble.

The screw nut has a right-hand thread as you can see on the picture.


Crank shaft bearing.

Up to a type 1 motor, the rolls of the left crank shaft bearings are running directly on the shaft.



Bearing mainshaft gearbox.

The mark maybe means 46 week of 1952


Washers mainshaft gearbox.

This two washers ajdusts the alignment of the two chainweels, to get a straight run of the chain.


Timing case with camshaft.

The camshaft is driven by helical Gear wheels. On older models there was a chain. How to remove the worm-gear wheel you find in the Puller for worm-gear wheel.



Cover of timing case.

Mounted in the cover of the timing case, there is a oil pump. This oil pump is driven by a worm gear.
There are two different oilpumps. This one is the old one, where a piston is working inside. The newer one is a toothed wheel pump.
Due to this, there ar also two different worm gear wheels (right winding, left winding).


Oil pump.

The lubrication of the motor is working like a dry sump lubrication.

The pump is working in two directions.
One direction is, to suck oil out of the oiltank and pump onto the critical parts of the motor.
The other direction is, to pump the oil back from the motor into the oiltank.


Foot shift control box.

A lot of desiccated grease, but better than rusty.

On the right side is the contact part for the detection the neutral gear.
The cable was cut off at the position, where it left the housing. So the control light in the headlamp wasn´t working.


Foot shift control box.

View from left side.


Cover of foot shift control box.

The axis of the gear lever has a lot of space. Looks like that the bush or the shaft is worn out.


Ratchet lever.

There ar two ratchets on the lever. They are hold apart by a spring.


Chain case.

After removing the foot control box completely, I found a possible source of the oil-leaking of the motor.
Maybe the sealing of the drive sprocket is damaged.


Stress marks.

Due to a low tension, the chain was sliding on the bottom of the chain case.


Cover of chain case.

Oil everywhere.


Stress marks on cover of chain case.

Also on the cover of the cain case i found stress marks.


Shaft of drive sprocket.

After removing the drive sprocket, you can see the alu gasket ring, which should retain the oil in the gearbox.
The grooves on the gasket are not from the removal of the drive sprocket. Maybe thats the reason of the heavy oil leakage.


Drive sprocket.

The worm gear on the shaft of the sprocket, is to transport the oil back into the gearbox, when the sprocket is turning.
At the first Models of the motor, it is intended that a minimal part of the oil comes out of the gearbox, to lubricate the chain.
Later models have a different drive sprocket without worm gear and a different sealing. There you have to lubricate the chain manually.


New drive sprocket.

In meantime i got the new drive sprocket.
It has s plain shaft. For sealing a simmerring is used.


Identification cover bolts.

The screws of the motorhousing have different lengths.
To get each screw back in place later, i put a mark on the housing. To mark the screws i used a tape.



Left motorhousing


Take care when opening the housing if you have the bearing, where the rolls running directly on the crankshaft.
In this case the rolls are bare in the bearing and its possible that the fall out.
To avoid this, i placed a old pipe through the bearings..






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