Suzuki Katana carburettors are precisely engineered and machined components. The carburettor regulates the amount of air allowed into the engine and delivers precisely metered fuel, which is atomised into the intake airstream. The carburettors are linked together so that, when tuned, the carburettor bank delivers exactly the same fuel/air charges to each cylinder, providing smooth and equal power pulses. Fuel with debris in it can clog up the jets in the carburettors, and old fuel can leave a varnish that adheres to all surfaces that it contacts in the carburettor, which gradually restricts the fuel flow. Either condition requires a rebuild and cleaning to rectify.
- Skill level:
Things you need
- Mechanic's tools
- Safety goggles
- Carburettor cleaner
- Shop rags
- Rebuild kit for each carburettor
Remove the throttle cable from the carburettor bank. Turn the fuel petcock off. Remove the fuel lines from the carburettor bank. Loosen the intake clamps with a screwdriver or nutdriver and pull the carburettors out of their intake grommets and free of the bike.
Remove the bowl bolts from each carburettor and discard the bowl gaskets. Remove the pivot pins from the floats and remove the floats and float needle valves. Unscrew the jets from their jet towers with a flat screwdriver. Inspect the jet orifices and passages in the carburettors for signs of trash or debris.
Spray the jets liberally with carburettor cleaner and let them soak to dissolve fuel varnish. Squirt carburettor cleaner into the passages and airways in the carburettors, including up the inside of the jet towers. Inspect these areas for signs of trash or varnish. Flush them liberally with carburettor cleaner to dislodge any trash and dissolve varnish. Mechanical slide and constant velocity type carburettors must also have their venturi slides cleaned and inspected for heavy scoring.
Remove the float needle valves from the floats and replace them with new ones. Ensure that the retainer clip is properly installed on each needle valve to prevent problems during reassembly. Position the float in place and guide the needle valve up into its recess. Install the float pivot pin by hand. Check the float height as per factory recommendations for your year of Katana.
Install the new float bowl gasket into its recess on the bowl. Push the bowl into position, being careful to not deform or roll the bowl gasket, and reinstall the bowl bolts. Tighten the bowl bolts firmly with a screwdriver.
Tips and warnings
- Keep the parts, floats, jets, etc. segregated during the process. The parts should be identical, but still it is good to not mix parts between carburettors if it can be helped.
- Wear safety goggles when spraying the carburettor cleaner. The cleaner is a strong solvent that can cause eye injury. Use in a well-ventilated area and do not smoke while working on the carburettors. Carburettor cleaner is volatile, and the gas remnants in the carburettors can be as well.