Reviving a Craigslist Motorcycle Project

InfoThis is a summary of the following YouTube video:

Buying a Motorcycle in a Box off Craigslist – Can We Make It Run?

BigTime

Nov 20, 2024

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Autos & Vehicles

Reassembling a Craigslist motorcycle project

  1. The team purchased a project motorcycle from Craigslist, which is currently disassembled. They aim to reassemble it to assess the risk involved in buying incomplete projects.
  2. Jerry, a self-proclaimed Project Vehicle Accumulator (PVA), frequently buys project vehicles, including a big rig and now a 2004 RM 125 two-stroke motorcycle.
  3. The RM 125 was bought as a potential source for a two-stroke engine for another project: converting a Rascal Mobility Scooter into a high-speed vehicle.
  4. The motorcycle was sold in pieces because the previous owner disassembled it for repairs but never completed the project.
  5. The team believes all necessary parts are present and plans to reassemble the motorcycle in under an hour to demonstrate the feasibility of such projects.
  6. The motorcycle parts arrived in two boxes and a grocery basket, with the engine being the primary component needed for the scooter project.
  7. The goal is to show that reassembling a disassembled motorcycle is straightforward and can be done quickly, encouraging others to undertake similar projects.

Reassembling a motorcycle from parts

  1. The project involves reassembling a motorcycle, specifically an RM 125, from parts bought on Craigslist. The motorcycle is currently in pieces, and the goal is to put it back together to assess its value.
  2. The reassembly process is broken down into four main steps: examining the frame, the engine, the suspension components, and the wheels. These steps help in organizing the reassembly process efficiently.
  3. Before starting the assembly, all parts are laid out to ensure that a complete bike can be built. This step is crucial to identify any missing components early in the process.
  4. The team faces a minor setback as Jerry's garage floor is scheduled to be epoxied soon, which could interfere with the project timeline.
  5. The video mentions the success of their merchandise, which sold out quickly, and expresses gratitude to their audience for their support. This success is attributed to their partnership with Shopify, a platform that helps manage their business operations.
  6. Shopify is highlighted as a key tool for their business, providing a platform to launch their store and manage sales both online and in-person. The platform's features, such as a drag-and-drop editor and marketing tools, are praised for their ease of use.
  7. The team emphasizes their commitment to working with brands they trust, like Shopify, which has helped them deliver products to their customers efficiently.
  8. The narrative concludes with Joby working on assembling the motorcycle's core components, including the triple trees, forks, and handlebars, indicating progress in the reassembly process.

Rebuilding a Craigslist motorcycle project

  1. The project involves rebuilding a 125cc two-stroke engine from a motorcycle bought in pieces on Craigslist. The initial step is to inspect the engine cases for any damage, as these are costly to replace. Common issues include cracks or previous repairs with welding or JB Weld.
  2. The condition of the crank is checked for play in the main bearing. While some side-to-side play is normal, the up-and-down movement should be minimal. The crank in this project appears to be in good condition.
  3. The piston shows signs of wear, with noticeable skirt damage, indicating it has been heavily used. Despite this, the top of the piston looks relatively new, suggesting some parts may have been replaced recently.
  4. The cylinder bore has visible damage, possibly from a cracked piston, but it seems repairable. A ball hone is used to clean the cylinder and create new cross-hatchings, which improve lubrication and reveal any imperfections.
  5. The seller claimed the engine runs, but a full rebuild is planned before using it extensively. This involves splitting the cases and replacing all parts to ensure reliability.
  6. While the engine is being worked on, the frame and suspension are assembled. This includes securing the forks, handlebars, and connecting components like the radiator.

Reassembling a motorcycle from parts

  1. The swing arm is a crucial component of the motorcycle, connecting to the frame and allowing vertical movement of the rear wheel. It absorbs bumps and rocks, functioning similarly to a control arm in a car but with more movement due to the nature of dirt biking.
  2. The motorcycle came with aftermarket reed valves, which are one-way valves that manage the air-fuel mixture. These valves open to allow the mixture in when the piston moves down and close during compression to prevent backflow. Checking for gaps in the valves can indicate when they need replacement.
  3. The process of reassembling the motorcycle involves various steps, including installing the swing arm and checking the engine components. The team works together to ensure each part is correctly fitted, highlighting the complexity and precision required in motorcycle assembly.
  4. Jerry, one of the team members, is noted for his hoarding tendencies, particularly with motorcycles and other items, which raises concerns among his peers. This adds a humorous and personal element to the narrative.
  5. The electrical work on the RM 125 involves connecting the ECU, which has three plugs for the ignition, kill switch, and Magneto. This setup is essential for generating electrical power from the engine, similar to a car's electrical system.

Reassembling a motorcycle from parts

  1. The process begins with checking the electrical system by grounding a new spark plug against the engine head and manually kicking the engine to check for a spark. A small spark indicates no electrical issues.
  2. The narrator emphasizes the importance of securing all parts properly, as leaving them loose can lead to project failure, especially with complex components like the carburetor.
  3. Carburetors often cause frustration due to gunk buildup, which occurs when fuel is left in the carburetor for extended periods, leading to clogs that affect the air-fuel mixture.
  4. Pump fuel, a mix of gasoline and ethanol, has a shelf life of about 30 days. Ethanol absorbs moisture over time, turning into a gel-like substance that clogs the carburetor jets.
  5. Clogged jets disrupt the precise air-fuel ratio needed for the engine to run smoothly, akin to a clogged artery in the human body, necessitating cleaning or replacement of the jets.
  6. The narrator performs 'open carb surgery' by installing new jets and cleaning the carburetor to ensure proper fuel flow.
  7. With the carburetor cleaned and reassembled, along with the engine and spark system in place, the motorcycle is nearly ready to be started.

Reassembling a two-stroke motorcycle

  1. The video begins with Jerry purchasing a disassembled RM 125 motorcycle from Craigslist, which he believes is a great deal despite it being in pieces.
  2. The team starts reassembling the motorcycle, beginning with attaching the airbox to the subframe, followed by the mud flap and rear fender, which connect to the frame and the carburetor.
  3. A discussion ensues about the unique design of two-stroke engine exhausts, particularly the expansion chamber, which is crucial for the engine's function.
  4. The expansion chamber's shape helps manage exhaust pressure waves, aiding in the intake and exhaust flow, which is different from four-stroke engines.
  5. The exhaust gases create a vacuum that draws in fresh air and fuel, and a pressure wave that reflects back to push unburnt fuel-air mixture into the combustion chamber.
  6. Aftermarket companies, like ProCircuit, design these pipes to enhance power output, likening the pipe to a musical instrument for the engine.
  7. The team humorously acknowledges their lack of geometry skills while working on the bike, highlighting the practical challenges faced during the assembly.
  8. After approximately an hour and 44 minutes, the team successfully assembles the motorcycle, transforming it from a box of parts to a functional dirt bike.
  9. The moment of truth arrives as they attempt to start the bike, expressing confidence in their work despite anticipating it to be loud.
  10. The bike starts, albeit running a bit rough, but the team is satisfied with the night's work, noting the achievement of making it run.

Reassembling a motorcycle from parts

  1. The team spent an evening reassembling a motorcycle purchased in parts from Craigslist, which was a cost-effective decision.
  2. They successfully saved money by buying the motorcycle in pieces and putting it together themselves.
  3. An additional engine was acquired for another project, referred to as the 'Rascal,' indicating future plans for further mechanical work.
  4. The team ensured legality by renting the street and obtaining a permit for their assembly activities, highlighting their adherence to regulations.