Replace Yamaha 2-Stroke Carburetor/Oil Pump Cables

| 6/11/2015 4:55:00 PM

1973 Yamaha RD350

If you’ve replaced carburetor throttle cables on a vintage 4-stroke engine, you know that the basic process is relatively simple. The complicating factor for anything other than a single-cylinder engine is making sure the carburetor slides are synchronized to each other so they pull off idle evenly. If your carbs are adjusted properly before you replace the cables, getting the slides synchronized isn’t that difficult, as we describe.


Vintage Yamaha 2-strokes equipped with Yamaha Autolube oil injection have one more component. These bikes have a cable working in conjunction with the throttle cables, operating an oil injection pump and increasing oil pump flow as throttle is applied. As a result, a 2-cylinder Yamaha 2-stroke such as our subject 1973 RD350 has four cables — two carburetor slide cables, one Autolube oil pump cable and one throttle cable at the handlebar twist grip. Additionally, the multicable setup has a cable junction that links the top or twist grip cable to the carburetor and oil pump cables. The cable junction can fail, falling apart from years of use. On our bike, a previous owner had clamped and zip-tied the junction to keep it in one piece.

If any one of these cables breaks or is damaged, you’re likely looking at replacing the entire cable assembly, as individual cables are increasingly difficult to find. Yet replacing them as a set is a good idea, as cables are service parts that have to be replaced occasionally. Regular use takes a toll, leading to stretched cables and worn-out cable housing ends. Nonuse does, too, resulting in sticking cables from years of sitting.

Original cable junction

Original “repaired” cable junction was on its way out.