We have compiled a list of the manufacturer-recommended tightening torques*.
It's happened to all of us: the workshop saying "Too tight and it breaks!" - SNAP - and suddenly it's true. Not a huge problem if you've only destroyed a nut or stud, these are usually easy to replace. It's already annoying when you don't have a spare on hand. Thread repair: It gets really annoying if you've damaged a thread in the engine case! That often becomes complicated and expensive, especially if it can't be repaired with a thread insert. Before replacing or welding the case, thread repair using Weicon adhesive might be an option.
Besides overtightening, there's also not tightening enough! Loose nuts or bolts can be dangerous. You don't want to imagine what could happen if wheel nuts or brake disks come loose. Loose carburetors, intake manifolds, or cylinders can quickly cause engine damage. Depending on the application, self-locking nuts or thread locker might be advisable!
It's also important to tighten screws and nuts evenly. Everyone knows this from changing tires-tighten in a cross pattern, for example, to ensure an even fit. On engine housings or cylinder heads, unevenly tightened studs should be avoided to prevent tension. Some components even require a specific tightening sequence. Always follow the manufacturer's instructions. 
Right-hand thread? Left-hand thread? Generally, nuts and bolts tighten clockwise (right-hand thread) and loosen counterclockwise. But there are exceptions like the flywheel nut on Lambretta and left mirrors, which often use left-hand threads.
For many jobs, you'll need special tools, pullers and especially holders-otherwise, parts often can't be loosened. You'll find the right tools for your scooter model after selecting it from the vehicle list:
For stuck connections, penetrating oil like WD40 often helps!
We recommend consistently using a torque wrench and adhering to the recommended tightening torques. We offer various torque wrenches for small and large jobs:
Lambretta Torque Specs
| Original | MB Developments | |
|---|---|---|
| Flywheel/Fan Nut | 68 Nm | 75 Nm |
| Exhaust/Intake Cylinder Nuts | 4.7-5.2 Nm | 9.8-11.8 Nm |
| Cylinder head nuts | 19-22 Nm | 20-24 Nm |
| Ignition Base Plate Screws | 4.7-5.2 Nm | |
| Gear Selector Bolt (9 mm) | 4.7-5.2 Nm | |
| Transmission Cover Nuts | 9.8-11.8 Nm | 14-17 Nm |
| Front Sprocket Bolt | 29-34 Nm | |
| Chain Cover Nuts (10 mm) | 4.7-5.2 Nm | |
| Rear Brake Cam Bolt (gear control) | 4.7-5.2 Nm | |
| Rear Wheel Bearing Cover Plate Nut | 4.7-5.2 Nm | |
| Brake Drum Nut (8° + 11° taper) | 161 Nm | |
| Brake Drum Nut (20° taper) | 203 Nm | |
| Brake drum nut lock | 14-14.7 Nm | |
| Fork Left | 54-55 Nm | |
| Front Axle Nut | 54-55 Nm | |
| Rim Fastening Nuts | 19.6-22.5 Nm | |
| Oil Seal Retaining Plate (gear control) | 4.7-5.2 Nm | |
| Chain Guide (gear control) | 4.7-5.2 Nm | |
| Transmission Spacer (gear control) | 0.07-0.30 Nm |
Torque Specs Vespa Largeframe pre-1977
| Nm | |
|---|---|
| Crankcase Halves Nuts | 12-15 Nm |
| Stator Plate Screw | 3-5 Nm |
| Clutch Nut | 40-45 Nm (up to 65 depending on clutch) |
| Secondary Shaft Nut | 30-35 Nm |
| Gear Selector Cross (left-hand thread, thread lock) | 15-18 Nm |
| Rotor Nut (Flywheel) | 60-65 Nm |
| Carburetor Mounting Screw | 16-20 Nm |
| Clutch Cover Screw | 6-8 Nm |
| Exhaust Manifold (P200) | 75-80 Nm |
| Exhaust to Cylinder Nut | 16-26 Nm |
| Aluminum Cylinder (follow manufacturer specs) | 14-16 Nm |
| Cylinder head groove (P 125 X, P 150 X, M7) | 16-18 Nm |
| Cylinder head groove (P 200 E, M8) | 20-22 Nm |
| Spark Plug (follow manufacturer specs) | 20-24 Nm |
| Engine Swing Arm Bolt | 60-75 Nm |
| Lower Shock Mounting Nut | M9 = 14-22 Nm, M10 = 16-24 Nm |
| Wheel Rim to Drum Mounting Nut | 20-22 Nm |
Torque Specs Vespa PX
| Nm | |
|---|---|
| Crankcase Halves Nuts | 12-15 Nm |
| Stator Plate Screw | 3-5 Nm |
| Clutch Nut | 40-45 Nm (up to 65 depending on clutch) |
| Secondary Shaft Nut | 30-35 Nm |
| Gear Selector Cross (left-hand thread, thread lock) | 15-18 Nm |
| Rotor Nut (Flywheel) | 60-65 Nm |
| Carburetor Mounting Screw | 16-20 Nm |
| Clutch Cover Screw | 6-8 Nm |
| Exhaust Manifold (P200) | 75-80 Nm |
| Exhaust to Cylinder Nut | 16-26 Nm |
| Starter Motor Groove (M8) | 10-15 Nm |
| Starter Motor Screw (M6) | 6-8 Nm |
| Aluminum Cylinder | 14-16 Nm (see manufacturer specs) |
| Cylinder Head Nut PX 125-150 (M7) | 16-18 Nm |
| Cylinder Head Nut PX 200 (M8) | 20-22 Nm |
| Spark Plug (see manufacturer specs) | 20-24 Nm |
| Engine Swing Arm Bolt | 60-75 Nm |
| Lower Shock Mounting Nut | M9 = 14-22 Nm, M10 = 16-24 Nm |
| Wheel Rim to Drum Mounting Nut (front/rear) | 20-22 Nm |
*We have compiled this information to the best of our knowledge, but we assume no liability for the accuracy.
Torque Specs Vespa Smallframe
| V50, PV, ET3 | PK | |
|---|---|---|
| Crankcase Halves Nuts | 13-15 Nm | 13-15 Nm |
| Stator Plate Screw | 3-5 Nm | 3-5 Nm |
| Kickstarter Screw | 23-26 Nm | 23-26 Nm |
| Primary Gear Nut | 50-55 Nm | 50-55 Nm |
| Clutch Nut | 40-45 Nm (up to 65) | 40-45 Nm (up to 65) |
| Gear Selector Fork Screw | 17-22 Nm | |
| Flywheel/Fan Nut | M10 = 45-50 Nm, M12 = 60-65 Nm | |
| Intake Manifold Nut | 6-8 Nm | 8-10 Nm |
| Exhaust Manifold to Cylinder (M6/M8) | 8-10 Nm | 8-10 Nm |
| Clutch Cover Screw | 8-10 Nm | PK 50: 8-10 Nm PK 80-125: 9-10 Nm |
| Brake Anchor Plate Nut | 17-22 Nm | 17-22 Nm |
| Engine Swing Arm Bolt | 38-50 Nm | |
| Brake Drum Nut | M14 = 60-100 Nm, M16 = 90-110 Nm | |
| Oil Drain and Fill Plug | 3-5 Nm | |
| Gear Shift Fork Screw | 17-22 Nm | |
| Exhaust Bolt to Engine Swing Arm | 18-20 Nm | 18-20 Nm |
| Pick-Up Screw | 2-2.5 Nm | 2-2.5 Nm |
| Fan mounting screw (Dynastart) | 8-10 Nm | |
| Dynastart Group Nut (?) | 60-65 Nm | |
| Aluminum Cylinder | 13-18 Nm (see manufacturer) | 12-18 Nm |
| Cylinder Head Nut | V50: 14-18 Nm | PK 50: 13-18 Nm |
| Cylinder Head Nut | PV, ET3: 14-18 Nm | PK 80-125: 13-18 Nm |
| Cylinder Base Nut | V50: 12-16 Nm | PK 50: 12-16 Nm (not HP) |
| Spark Plug (see manufacturer) | 14-18 Nm | 18-24 Nm |
| Rear Axle Stub Nut (under swing cover) | 50-55 Nm | 50-55 Nm |
| Locking Nut Front Axle (V50 w/ or w/o speedo drive) | 45-50 Nm | 45-50 Nm |
| Speedo Drive Ring Nut | PV/ET3: 45-50 Nm | |
| Upper Shock Mount Nut | 20-27 Nm | PK 50: 20-30 Nm PK 80-125: 30-40 Nm |
| Lower Shock Mount Nut | 20-27 Nm | PK 50: 20-30 Nm PK 80-125: 20-27 Nm |
| Engine Swing Arm to Frame Nut | 38-52 Nm | 38-52 Nm |
| Upper Headset Bearing Ring (hand-tight to bearing contact) | 6-7 Nm (check) | 50-60 Nm (check) |
| Lock Ring for Upper Headset Bearing (after reaching torque, back off ~1/4 turn) | 50-60 Nm (check) | |
| Handlebar Bolt | 30-44 Nm | 30-44 Nm |
| Notched Nut Upper Headset Bearing | 30-40 Nm | |
| Rear Axle Nut | 90-110 Nm | 90-110 Nm |
| Wheel Nuts front/rear to Brake Drum | 23-27 Nm | 20-27 Nm |
| Front Wheel Central Nut | 75-90 Nm | PK 50: 50-80 Nm PK 80-125: ? |
*We have compiled this information to the best of our knowledge, but we assume no liability for the accuracy.
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