Rotax 532 disassembly, Rotax 532 aircraft engine rebuilding manual.



Looking for a heater to keep you warm while flying? Click here for more information!

Rebuilding  the Rotax  532 ultralight aircraft engine.

Removal -Engine from aircraft

To remove the 532 Rotax liquid cooled engine from the aircraft it may be necessary to remove or disconnect the following:

.if necessary
-drain then disconnect cooling system from engine.
-disconnect fuel lines
-disconnect fuel pump
-disconnect throttle cables
-disconnect air filter or air intake silencer box
-disconnect carburetors at rubber intake flange
-disconnect wiring harness from engine
-disconnect any temperature sending units from engine
-remove prop and store in safe place
-if necessary disconnect reduction drive
-if necessary remove recoil
-if convenient remove exhaust system
-remove remaining engine assembly from aircraft

Engine is extremely heavy and awkward. Do not attempt to remove from aircraft without adequate help!


If aircraft is equipped with a battery disconnect the battery ground cable before starting any work!


If engine is hot allow to cool before starting any work!


Prior to disconnection label all wiring for proper reinstallation!

Disassembly -Exhaust Manifold/Recoil removal

Tools Required
10 mm deep reach socket
6mm allen wrench

With a 6 mm allen wrench loosen, then remove the 4 allen head screws used to retain the exhaust manifold to the cylinders. The manifold will then come free.

Using the 10mm deep reach socket and ratchet remove the 4 bolts, or 6mm allen head screws retaining the recoil to the two crankcase halves

Once the 4 bolts/screws have been removed the recoil will come free.


-Inspect ball joint at end of exhaust manifold for wear.
-Inspect manifold, for warpage .
-Inspect the recoil housing for cracking around the center, and where the recoil rope exits the housing.
-Inspect for proper recoil return spring action.
-Inspect the recoil rope for fraying.


Note the position of the recoil in relation to the engine installation for proper recoil starter rope angle during reassembly.

Disassembly -Starter pulley assembly

Tools Required.
6 mm allen wrench
13 mm socket
locking pin
plastic mallet


Located behind the recoil starter assembly is the starter pulley .To remove it lock the crankshaft, by placing the locking pin (supplied with the Rotax engine tool kit), into the fuel pump impulse hole.

Then slowly turn the engine over until it locks.

With the crankshaft locked use a 6mm allen wrench, electric start models use 13 mm socket head bolts, to remove the 3, retaining bolts. This allows the removal of the recoil cup.


This is a special locking pin developed for this purpose. The use of any other tool, or material may cause serious damage to the engine.

Disassembly -Magneto removal

Tools Required
Locking pin
Magneto puller
30mm socket
3 bolts, proper length


To remove the magneto nut from the end of the crankshaft, install the outer half of the flywheel puller. To align the holes in the puller correctly, rotate the crankshaft. Position the puller so that the puller extension locks into the hole in the lower crankcase half. With the puller bolts snug and the crankshaft locked use a 30 mm socket and ratchet to remove the magneto nut, and lock washer. In order to allow the socket to fit inside the puller half it may be necessary to grind the sides of the socket down.


Make sure that the puller bolts are the correct length. The use of incorrect bolts can strip the magneto threads and/or damage the internal coils.

Part # 940-580 - 3 required

Disassembly - Magneto removal

Once the nut and washer are removed install the inner half of the puller. With the puller locked in position and the 3 bolts snug, turn the puller bolt in using a wrench, or socket. If a considerable amount of pressure is required remove the socket and using a hammer,. carefully, strike the puller bolt sharply. Reinstall the socket and tighten down on the puller bolt, until the magneto comes free. Then by hand pull the magneto clear of the crankshaft and engine.


-Inspect the key way area for signs of wear.
-Inspect the interior of the magneto for foreign material.
-Inspect the crankshaft end for signs of wear.
-Inspect lock washer and nut for signs of damage.


During removal of the magneto, the key used to align the magneto to the crankshaft may come loose, and can be easily lost. When pulling the magneto free be careful not to loose the key, or that it does not get pulled into the magneto.

Disassembly - Carburetor removal

Tools Required
Small Phillips screw driver
Blade screw driver


If still connected use a blade screw driver and remove air cleaner(s) from carburetors. Then using a Phillips screw driver loosen clamp retaining carburetors to rubber intake manifolds. With the clamp loose gently pry down and back on carburetor and it will come free of manifold..


-Inspect rubber intake flanges for damage or cracking. Inspect areas around two retaining bolts, and under clamp very carefully.
-Inspect carburetor bowl gasket for pinching or cracking.
-Inspect floats for leakage.
-Inspect air filter(s) for damage

Replace all rubber sockets with a flat side on one side.

Disassembly -Draining rotary valve oil

Tools Required
-13 mm deep reach socket
-blade screw driver

Shop supplies
Oil drain pan.


Before removing the rotary valve tank bracket, it is first necessary to drain the rotary valve tank. On early model engines it will be necessary to remove the hose connected to the tank, from the outlet located directly below the carburetors, on an engine installation where the spark plugs are facing up.

To do this. loosen off the tank cap, use a blade screw driver, and loosen the lower hose clamp, then using the screw driver, while exerting pressure on the hose gently remove the hose from the outlet. This will allow the oil to drain from the engine and rotary valve tank.

On new model engines there will be a drain plug (10mm socket head) located directly below the water pump housing on the exhaust side of the engine. Removal of the drain plug will allow the oil to drain from both the tank and engine.

Once the rotary valve tank hose, or the drain plug, is removed the oil will spill out.

Disconnect lower hose here
(Early models) Remove drain plug here
(Later models) Loosen cap before draining system

Disassembly - Rotary valve tank bracket

Tools Required
-10 mm deep reach thin walled socket
-13 mm deep reach socket
-blade screw driver


Using a 13 mm deep reach socket remove the two top bolts retaining the rotary valve cover plate to the engine. Loosen but do not remove the two lower bolts. Using a 10 mm deep reach thin walled socket remove the two 10 mm nuts, flat washers and lock washers holding the water outlet socket in place. It may be necessary to push gently over on the rotary valve hose to allow placement of the socket. With these removed gently tilt the rotary valve plate outward, then using a blade screw driver loosen off the clamp holding the rotary valve hose to the top engine outlet. With the hose removed the complete bracket with coils will now come clear of the engine.

To remove the bracket completely, disconnect the two wires running to the ignition suppressor box, and the two leads running to the top of the coils. Next remove the nut from the back of the bracket which retains the bolt holding the ground wire. With all the wiring removed the plate should be come free of the engine.


There is little room between the end of the bolts and the cylinders. Incorrect bolt installation on reassembly, can cause severe damage to the rotary valve plate securing ears.

Remove top two bolts, but only loosen bottom two bolts.

Disassembly - Rotary valve plate and rotary valve

Tools Required
13 mm socket


To completely remove the rotary valve plate remove the two remaining bolts from the bottom of the plate. Carefully lift the cover off. Remove the rotary valve, wrap it in cloth, and store in a safe place. Be careful not to loose or damage large sealing 0 ring.


-Inspect hoes for damage
-Inspect tank for damage
-Inspect tank bracket for damage
-Inspect tank cap for wear or damage
-Inspect rotary valve plate for damage
-Inspect intake manifold flanges for wear/damage
-Inspect washers for damage
-Inspect ignition coils for damage/wear at retaining brackets


Wrap rotary valve in cloth and store in safe place.

Disassembly - Cylinder head

Tools Required.
13 mm socket


To remove the cylinder head remove the, 13 mm nuts located in the top of the cylinder head starting from the outside of the head and working in. Lift the cylinder head off. Remove the head gaskets. Remove two outer rubber sealing rings

-Inspect the interior dome of the cylinder heads for signs of damage.
-Inspect the cylinder head rings for signs of leakage or damage
-Inspect outer sealing rings for damage

Disassembly - Cylinder Removal.

Tools Required
Rubber mallet


To remove the cylinders use a 13 mm thin walled deep reach socket, or 6 mm allen wrench depending on which your engine has and remove the 4 bolts/screws holding the cylinders to the upper crankcase.
With the nuts/screws removed the cylinders can be GENTLY lifted off. Be EXTREMELY careful that damage is not done to the piston skirts during removal of the second cylinder.


-Inspect the interior of the cylinder for signs of wear or damage.
-Inspect the interior of the cylinder for signs of seizure.
-Inspect the interior of the cylinder for signs of aluminium deposits.
-Inspect the cylinder with your finger about 5/8 of an inch from the top for signs of wear.


During cylinder removal ensure that the pistons and connecting rods do not bang against the side of the crankcase halves.

Disassembly - Removal Wrist pin clips

Tools Required
Circlip removal tool #H4435
Rag or paper towel
Eye protection


For disassembly it is only necessary to remove two wrist pin clips, the clips on the PTO side and Magneto side of the pistons.

While wearing eye protection, carefully insert the point of the tool into the groove on the side of the wrist pin hole, until it is under the wrist pin clip.

Using a rag or a towel with your other hand cover the clip area. Now slowly apply pressure and pry the clip out.


The wrist pin clip is very springy, use a rag or other material to prevent it from flying free. Wear eye protection. Clear work area of bystanders.

Disassembly -Removal Wrist pins

Tools Required
-wrist pin puller/socket/screw driver
-small hammer


To remove the wrist pin raise the magneto piston to the top of its travel. Insert the wrist pin puller Part # H 4430 through the pin, lock the puller clip tighten up the puller and extract the pin.

To remove the wrist pin with a socket, use a socket that is a smaller diameter than the pin (a 10mm deep reach thin walled socket with a short extension works). Come in from the side of the pin that still has the wrist pin clip in it, gently apply pressure until the pin comes free.

-Inspect the wrist pin clip retaining groove for signs of wear.
-Inspect the wrist pin bearing for signs of wear or contamination.
-Inspect the wrist pin for signs of bluing ( an indication of heat), wear, or damage.
Inspect for slop in piston the up and down direction


If your engine is equipped with cageless wrist pin bearings these bearings will fall out once the wrist pin is removed. Take whatever steps necessary to prevent their loss. There are 31 needle bearings in the new cageless bearings.

Disassembly -Removal Pistons


Once the pin is free remove the piston, and wrist pin bearing. To prevent damage to the piston never place the piston on its skirt, always lay it on its dome. Using marker or scribe to identify pistons magneto and PTO.

Repeat the procedure for the piston on the PTO side.

-Inspect the dome of the piston for signs of damage.
-Inspect the dome for signs of carbon build up, and ignition burning pattern.
-Inspect the rings for signs of damage.
-Inspect the piston sides for signs of seizure.
-Inspect the rings for signs of seizure and carbon build-up.
-Inspect the ring dowels for signs of damage or wear.
-Inspect the ring lands for signs of damage/wear/carbon build up.
-Inspect the piston sides for signs of wear or damage.
-Inspect the base of the skirts for shine, indicating piston slop.
-Inspect the underside of the piston dome for carbon build up.


If your engine is equipped with cageless wrist pin bearings these bearings will fall out once the wrist pin is removed. Take whatever steps necessary to prevent their loss. Ensure you have 31 bearings.

Disassembly -Stator unit removal

Tools Required
4 mm allen wrench


.. Note routing of wiring! Remove the two allen screws, washers, and lock washers holding the stator plate to the crankcase halves. Remove rubber grommet protecting wires. The stator unit will now come free, slowly pull the stator plate out while carefully pulling the wiring harness through the crankcase hole. Once the wires are free the stator unit can be completely removed from the engine.

-Inspect the stator unit for signs of wear or damage.
-Inspect the points and condensers for signs of oil contamination.
-Inspect points for signs of wear.
-Inspect the coils for damage.
-Inspect the wiring for wear, cuts, or pinching. .


Be careful not to cut or bare the wires on the sharp edges of the crankcases while pulling them through the crankcase hole.

Disassembly - Separating crankcase

Tools Required.
10 mm socket
13 mm socket
6 mm allen wrench
Screw driver
Rubber mallet


To separate the crankcase halves, turn the remaining engine assembly upside down. Remove the , 10 mm socket head bolts from the outside of the cases. Remove the remaining 13 mm/6mm allen socket head bolts, from the casing, starting from one end and working to the other.

With all of the bolts removed, insert a screw driver into the non sealing area between the crankcase halves and pry up gently in several places on both sides of the casing.


Some of these 13 mm bolts at the PTO end of the casing have been changed to allen head screws to allow for easier socket, and gear drive installation.

Disassembly - Crankcase

Then using a rubber mallet gently tap the crankshaft at either end to break it free from the casings. The bottom crankcase should now come free.

After the bottom case has been removed, remove the crankshaft, by placing your hands around the crank at either end and using your thumbs pry down on the casing while lifting up on the crank until it comes free.

-Inspect the bolts for signs of corrosion.
-Inspect the seals for signs of leakage.
-Inspect the crankcase halves for signs of damage.
-Inspect the crankcase halves for signs of wear in the bearing retaining areas.
-Inspect the crankshaft bearings for signs of wear.
-Inspect the connecting rods for signs of wear or heat.
-Inspect the center crank spacer for signs of seizure.
-Inspect the crankshaft key way for signs of wear.
-Inspect rotary valve sealing area
-Inspect rotary valve shaft
-Inspect rotary valve gear.

Disassembly-Rotary valve shaft

Tools Required
10 mm socket
screw driver
Snap wring pliers


Using the snap ring pliers remove snap ring from carburetor end of rotary valve shaft.

Water pump housing/impeller removal

Remove the water pump housing, it is retained by 4, 10 mm socket head self threading bolts. This will expose the water pump impeller and retaining nut. Remove the 10 mm nut, and flat washer. Remove the impeller, remove the special serrated washer and flat washer.

Located directly below the exhaust manifold is the water pump housing, it is retained by 4, 10 mm socket head self threading bolts, remove these and the housing can be removed.

This will expose the water pump impeller and retaining nut. Remove the 10 mm nut, and flat washer. Remove the impeller, remove the special serrated washer and flat washer.


It may be necessary to gently tap the housing with a plastic hammer to break it free from the sealing gasket.


It is sometimes necessary to apply pressure to the sides of the water pump impeller to break it free from the shaft.

Disassembly-Rotary valve shaft .


Insert the extrusion jig (part # 876 612) onto the water pump end of the rotary valve shaft, threading it in until it is butts against the end of the shaft.

Carefully, and forcefully strike the end of the jig with a hammer. This will drive the rotary valve shaft out the intake side of the crankcases.

Tools Required
small screw driver
extrusion jig
half of bearing puller tool

Pressing the gear end of the rotary valve shaft against your body, with your fingers apply pressure down on the spring holding cup, (2) break the circlip (1) free from its retaining groove on the rotary valve shaft. This will allow removal of the spring (3) gear (4) shim O ring (5).

To remove bearing, spacer and shim, install the lower half of a bearing puller in behind the bearing, supporting the bearing and shaft carefully hit the end of the extrusion jig protecting the other end of the shaft.

Disassembly-Rotary valve shaft

Another procedure that can be used is a small press. Support the bearing., and shaft then gently press down on the jig protected end of the shaft until the bearing, spacer and shim come free.

Bearing removal
To remove remaining bearing insert bearing removal tool, 876 500 into exhaust side of rotary valve hole and carefully and forcefully strike with a hammer until bearing comes out.


Use extreme Caution when hitting shaft. Make sure the driving force is straight down onto the shaft end, or damage to the shaft will result.
Have high speed internet & Real Player installed? Subscribers to the Ultralight Flyer web video magazine have access to Rotax Engine Rebuilding videos right on the web.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16   Index for this section.


Ellef Air, light sport and ultralight aircraft sales, service and repair.

Ultralight Aircraft News Web Magazine .-.-.-. . No part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic,  mechanical, manual, or otherwise,  without written permission . By copying or paraphrasing the intellectual property on this site, you're automatically signing a binding contract and agreeing to be billed $10,000 payable immediately. Copyright Ultralight News -  Ultralight Flyer.