HPI Tutorial - How to Clean Your Baja 5b Pull Start and Engine
The Baja 5b 1/5 scale buggy is an off road vehicle. When driving off road your buggy may get dirty, especially if used in damp conditions. It is important to keep the engine and pull start of the Baja 5b clean to keep it running reliably and to maintain top performance.
Pull Start Cleaning
The pull start unit on the Baja 5b may need regular maintenance if the buggy is run in damp or dirty conditions.
The pull start may fail to operate after your Baja 5b has been run in damp conditions and then left to dry. This is caused by contamination with grit or dirt, but this is really easy to fix by cleaning.
To clean the pull start mechanism you first need to remove it from the engine. To do this first you need to remove the left rear wheel from the buggy to gain access to the screws that hold on the pull start mechanism.
With the left rear wheel removed you have access to the 4 screws that hold on the pull start mechanism. Undo these 4 screws with the supplied 3mm allen key.
Undo the screws that hold on the pull start mechanism
With the complete pull start mechanism removed you can see the moving parts of the mechanism.
To clean the mechanism you need to take it apart. To do this you need to unscrew the screw that holds it together.
Undo the screw that holds the pull start mechanism together
Remove the screw and the metal plate. Now you can remove the sliding part of the mechanism so that you can clean the sliding surfaces properly. It is grit and dirt on these sliding surfaces that cause the pull start mechanism to stick.
Remove the sliding part of the pull start mechanism
Remove the sliding part of the pull start mechanism by lifting and twisting in a clockwise direction. Now you can clean the pull start mechanism, pay special attention to the surfaces that slide over each other. Dirt and girt on these surfaces causes the mechanism to stick.
Brush off dirt and grit from the sliding part of the pull start
Brush dirt and grit from the pull start mechanism
Once you have cleaned the moving parts of the pull start re assemble it and then pull the pull start handle a short way out. The sliding part of the pull start should move out from the pull start mechanism. When this part moves outwards it engages with the flywheel of the engine, allowing the engine to be turned.
The sliding part will move out if the pull start is operating correctly
Before re-attaching the pull start mechanism to the engine it is a good idea to clean the flywheel, paying particular attention to the fins on the flywheel. These fins draw cooling air through the pull start housing, if they are full of dirt and grass they will not be as effective and the engine cooling will be reduced.
Remove dirt and debris from the flywheel area
Once you have cleaned the pull start and the flywheel you should reattach the pull start mechanism to the engine.
As the engine is air-cooled it is important to keep the outside of the engine clean. Airflow around the engine removes heat from the engine and keeps the engine in the normal operating temperatures. If the outside of the engine becomes covered in dried on dirt the engine may overheat.
To clean the engine you need to brush off any mud, dust, grass etc from the outside of the engine. Pay special attention to the air slots in the pull start housing as this is where cooling air is sucked in.
Remove dirt and debris from the slots in the pull start housing
You also need to clean the engine cylinder head cooling fins. The engine is cooled by air passing over these fins, if they are covered in dirt the engine cooling will be less effective and the engine may get hot.
Use a brush to remove dirt from the fins
With the engine clean and free from dirt and debris it will run cooler and give you the best performance.