Installing Mikuni Carbs on the Honda CB350 | Fuel Line Solution

Fitting Mikuni performance carburetors to a classic Honda CB350 can create an unexpected problem — the original fuel line arrangement may no longer work.

In this episode of the 1971 Honda CB350 Scrambler café racer build, I work through the fuel routing problems and come up with a practical solution for getting fuel to the Mikuni carbs cleanly and reliably.

Before tackling the fuel system, I finish the custom fuel tank paint, apply the final stencils and one-part 2K paint, and fit an LED headlight. Then it's time to tune the Mikuni carburetors and get the engine running again.

The main challenge is the fuel line routing. With the Mikuni performance carbs fitted, the original setup doesn't provide the right connections or routing, so I look at alternative fuel petcocks, different fittings and ways of rerouting the fuel lines. The eventual solution uses a T connector to create a workable fuel supply for both carburetors without compromising the installation.

In This Episode

• Finishing the Honda CB350 custom fuel tank paint

• Applying one-part 2K paint and custom stencils

• Fitting an LED motorcycle headlight

• Installing Mikuni performance carburetors

• Tuning the Mikuni carbs

• Troubleshooting motorcycle fuel line routing

• Looking at alternative fuel petcocks

• Adapting fuel fittings for Mikuni carburetors

• Using a T connector to reroute the fuel lines

• Finding a practical fuel line solution

• Starting the Honda CB350

• Getting the engine running successfully

With the fuel system finally sorted, the Honda CB350 is running and the café racer build is very nearly complete. This episode shows some of the less obvious problems that can crop up when fitting performance carburetors to an older motorcycle, along with a simple real-world solution to the fuel routing issue.

This 1971 Honda CB350 Scrambler project documents the transformation of a partly built classic Honda into a custom café racer, covering the mechanical work, fabrication, paint, electrics and finishing details involved in a garage-built motorcycle project.

If you're working on a Honda CB350, fitting Mikuni carburetors, building a café racer or simply trying to solve motorcycle fuel line problems, this episode should give you some useful ideas for adapting the fuel system to suit a custom carburetor setup.