Dismanteling the new 250/300Fi 2S TM Racing engine

The TM Racing 250 / 300Fi 2S engine is new in 2020. To help you maintain your tm racing motorcycle. We wanted you to do a tutorial presenting the complete disassembly from A to Z, or should we say from cylinder head to the gearbox.

The different stages concerning the reassembly of the engine are indicated in bold.

Removing the pinion cover from the TM Racing

Démontage moteur 250/300Fi 2S 2020 - Photo 1

1 - Unscrew the two screws (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 2

2 - Remove the pinion cover (2) and the protection bracket (3). 

Upon reassembly, make sure that the two bushes (4) are present on the pinion cover (2). Tighten the two screws (1) with a torque of 15 Nm

Démontage moteur 250/300Fi 2S 2020 - Photo 3

3 - Remove the seeger ring (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 3

4 - Remove the pinion (2).

Temperature sensor removal of the TM Racing 250Fi 2S engine

Démontage moteur 250/300Fi 2S 2020 - Photo 5

1 - Unscrew the sensor (1) and remove it from the head. Check that the OR gasket (2) is not damaged.

When refitting, smear the thread (3) with lithium grease and screw with a torque of 30 Nm

Démontage moteur 250/300Fi 2S 2020 - Photo 6

2 - Remove the spark plug and the temperature sensor as described in the relative paragraph.

Undo the screws (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 7

3 - Remove the head (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 8

Upon reassembly, replace the seals (3) and screw the screws (1) without tightening, then tighten them crosswise with a torque of 20 Nm

Injectors disassembly of the TM Racing 300Fi engine 2020

Before disassembling the injector, the area around the injector must be clean.

Démontage moteur 250/300Fi 2S 2020 - Photo 5

1 - Unscrew the two screws (1). Collect the two Teflon washers (2) for each screw.

Démontage moteur 250/300Fi 2S 2020 - Photo 6

2 - Remove the injector (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 7

3 - Remove the injector (3) from the duct (4), clean it and put it in a plastic bag so that it does not get dirty. If the duct (4) with its piping must also be dismantled, also put these in a plastic bag so that they do not become dirty.

Cylinder and piston of the 250 2 stroke injected

The drain valve nut (1) must be screwed or unscrewed only when the valve has to be overhauled and only with the cylinder removed.,Do not act on the nut (1) with the cylinder mounted as there may be adjustment problems.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Unscrew the nuts (2) as follows: L oosen the nuts (2) then completely unscrew the nuts (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Remove the cylinder (3) by sliding it from the stud bolts.

Démontage moteur 250/300Fi 2S 2020 - Photo 20

3 - Remove the gasket (4).

Démontage moteur 250/300Fi 2S 2020 - Photo 21

4 - Remove the lock ring (5) of the piston (6)

Démontage moteur 250/300Fi 2S 2020 - Photo 22

5 - Extract the pin (7) and remove the piston (6).

Démontage moteur 250/300Fi 2S 2020 - Photo 23

6 - Remove the roller cage (8).

Reed valve pack from the TM Racing 300Fi 2020

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Unscrew the screws (1) that fix the external frame (2) of the reed valve pack.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Check the rubber fitting (3) on the carburettor/throttle body, if damaged, cracked, etc. replace.

Démontage moteur 250/300Fi 2S 2020 - Photo 20

3 - Check the OR gasket (4); if damaged, replace.

Démontage moteur 250/300Fi 2S 2020 - Photo 21

4 - Remove the reed valve pack (5) and the relative gasket (6); if damaged, replace.

Démontage moteur 250/300Fi 2S 2020 - Photo 21

5 - Remove the internal frame (7).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

6 - Remove the external blades (8).

Démontage moteur 250/300Fi 2S 2020 - Photo 20

7 - With a screwdriver, slide out the two internal stops (9).

Démontage moteur 250/300Fi 2S 2020 - Photo 21

8 - Remove the internal blades (10). Check the state of the blades, if chipped or deformed, they must be replaced.

Dismantel clutch and clutch actuator of the TM Racing 250Fi 2020

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Unscrew the screw (1) and remove the actuator (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Remove the piston (3). Check the conditions of the OR gaskets (4 and 5); replace them if ruined. On re-mounting, lubricate the gaskets with clutch oil.

Démontage moteur 250/300Fi 2S 2020 - Photo 21

3 - Unscrew the M5-L25 screws (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - Remove the flywheel cover (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

5 - Remove the gasket (3). Use a new one on the re-assembling process

Démontage moteur 250/300Fi 2S 2020 - Photo 20

6 - Retrieve the two centring bushes (4). On re-mounting, check that the two centring bushes (4) are positioned correctly. Clean the surface of the cover and the split crankcase of any residues and check that the gasket (3) is not damaged, otherwise replace. Tighten the screws (1) with a torque of 8 Nm

Démontage moteur 250/300Fi 2S 2020 - Photo 20

7 - Unscrew the two grub screws (1). Remove the sensor (2). Reassemble everything in the reverse order of disassembly, taking care to position the non-threaded part of the grub screws (1) in the brass bushes (4). 

Démontage moteur 250/300Fi 2S 2020 - Photo 21

8 - Position the cable harness (5) as originally and reassemble the flywheel housing.

Démontage moteur 250/300Fi 2S 2020 - Photo 21

9 - Remove the flywheel cover as described in the relative section. Unscrew the screws (1) that secure the stator (2). Unscrew the screws (3) and remove the stop plate (4). Remove the stator (2) with the relative cabling.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

10 - Unscrew the two screws (1) and remove the pick-up (2).On re-mounting, check that the washers notched under the screws (1) are positioned correctly. Tighten the two screws (1) with a torque of 8 Nm (0.8 kgm, 5.9 ft/lb) + Loctite 243. Make sure the rubber cap (3) is fitted correctly on the guard.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

11 - Block rotor rotation (1) and use an impact gun to loosen the nut (2) with relative curve washer (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 20

12 - Screw the extractor (4) onto the thread of the rotor (1) and tighten the screw (5) to detach the rotor (1) from the crankshaft.

Démontage moteur 250/300Fi 2S 2020 - Photo 20

13 - Remove the complete rotor (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

14 - Retrieve the key (6). Make sure the key (6) is properly positioned in its housing.

Starter motor of the 300 2 stroke TM Racing engine

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Remove the Bendix starter (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Unscrew the two starter motor fastening screws (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

3 - Remove the starter motor (3).

Water pump of the 250 2 stroke TM Racing engine

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Undo the screws (1); the screw (1a) is the system drain screw and is equipped with an aluminum washer (2). Remove the pump cover (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Check the condition of the gasket (4) if damaged, replace. Remove the transmission cover (5) as described in the relative paragraph.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Put aluminum jaws (6) in a vice and lock the shaft (7) of the water pump.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

4 - Unscrew the impeller (8).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

5 - Remove the shaft (7) from the crankcase (5).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

6 - Check the condition of the seal (9) if damaged, replace. Check the correct functioning of the bearing (10), if it does not slide freely replace; to replace, heat the crankcase to a temperature of 50° C and with a punch remove the bearing and reassemble the new one.

Transmission guard of the TM Racing

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Unscrew the screws (1)

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Remove the guard (2), with the aid of a rubber hammer.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Remove the gasket (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

4 - Recover the three centring bushes (4).

Idle Kick starter removal

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Release the spring (1) from the relative housing, turn the starter (2) anticlockwise by 1/4 of a turn.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Remove the starter (2) complete with spring (3) and washer (4).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - In sequence, remove the washer (4), spring (3), socket and ratchets (5), the seeger (6), shim (7), gear (8), shaft (9), socket (10) and the spring (1).

Drum and clutch bell of the TM racing 300Fi 2S engine

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Open the lock washer (1) with a chisel.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Use a spanner to block rotation of the clutch drum (2) and tighten the nut (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Remove the safety washer (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - Remove the drum (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

5 - Remove the washer (4).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

6 - Remove the bell (5).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

7 - Remove the two roller bearing (6) and the spacer (7). Remove the washer (8).

Transmission side counter gears

Démontage moteur 250/300Fi 2S 2020 - Photo 18

Components layout: :

1. Countershaft gear
2. Idle gear kick starter removal
3. Kick starter
4. Gearbox primary shaft
5. Gearbox command shaft
6. Crankshaft gear

Démontage moteur 250/300Fi 2S 2020 - Photo 19

1 - Remove the pedal start gear (3) as described in the relevant paragraph.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

2 - Unscrew the fixing screw (7) of the pedal start retaining gear (2) .

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Remove the screw (7) and the washer (8). Remove the gear (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - Unscrew the screw (9) of the countershaft (1). Remove the gear (1).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

5 - Collect the key (10).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

6 - Retirer le clip (11) du pignon (6) de l'arbre de vilebrequin et retirer le.

Gearbox control shaft and ratchets holder removal

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Turn the gearbox putting the 5th or 6th gear according to the type of engine. Remove the transmission casing and the countershaft gear as described in the relevant paragraph. Remove the gearbox control shaft (1) and recover the shim (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Remove the socket (3).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Unscrew the two screws (4).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - Remove the pawl ratchet plate (5). Remove the ratchet support (6) from the plate (5).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

5 - Dismantle the ratchets (7) and (8) with the relative tips (9) and the springs (10).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

6 -Unscrew the pin (11) securing the desmodromic shaft head (12). Remove the pin (11).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

7 - With a screwdriver (13) move the rod (14) and with a screwdriver (15) lever to remove the ring nut (12).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

8 - Remove the ring nut (12).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

9 - To remove the rod (14) unscrew the screw (16).

Semicase separation of the TM Racing 250Fi 2S 2020

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - On the transmission side, remove the gearbox secondary shaft locking seeger (1). Unscrew the screws (2) M6 x 50 and the screw (3) M6 x 35.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - Turn the engine on the ignition side and remove the countershaft (4).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Undo the screws (5). Take not to forget any.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - With a rubber hammer open the two split crankcases (6) and (7).

Crankshaft, gearbox, gear drum of the TM racing 300Fi 2S engine

Démontage moteur 250/300Fi 2S 2020 - Photo 18

Components position :

1. Crankshaft
2. Gearbox primary shaft
3. Gearbox secondary shaft
4. Gears selector drum (desmo)

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 -Using a rubber hammer, slide the complete crankshaft (1) from the semicase. If necessary, heat the bearing to facilitate removal of the crankshaft.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Extract the secondary shaft fork pin (1) complete with fork (2).

Démontage moteur 250/300Fi 2S 2020 - Photo 18

4 - Slide the primary shaft fork pin (3) out.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

5 - Spread the forks and remove the gear selector drum (4) (desmo).

Démontage moteur 250/300Fi 2S 2020 - Photo 19

6 - Remove the fork (5) of the primary shaft.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

3 - Remove the complete gear assy (6) with the fork inserted.

Démontage moteur 250/300Fi 2S 2020 - Photo 18

Primary shaft, gear sequence

Démontage moteur 250/300Fi 2S 2020 - Photo 18

Secondary shaft, gear sequence

Bearing replacement 250/300Fi 2S 2020

Démontage moteur 250/300Fi 2S 2020 - Photo 18

1 - Unscrew the screws (1) that block the bearing and remove the plates (2). Unscrew the screw (3) with relative bearing safety washer. After having replaced the bearings, re-position the safety washers and tighten the screws again and applying Loxeal 82-33 on the thread.

Démontage moteur 250/300Fi 2S 2020 - Photo 19

2 - After having the case warmed at around 50°C extract the bearing.

Your 2020 TM Racing 250 or 300Fi engine is now completely disassembled. Only reassemble your engine with original parts guaranteeing its reliability. All original parts are available, in case of doubt, do not hesitate to contact us.

Find all our others tutorial :