Manufacturer: Tillotson
Carburetor Series: HR Series
Primary Equipment Application: Stihl 070 / 090 Contra Big Timber Saws
Before ordering, inspect the carburetor body to confirm the stamped model number (RK-21HR). This carburetor uses standard HR Series internal components.
Recommended for machines that have been in long-term storage or exposed to ethanol fuel degradation. Includes fuel pump diaphragm, metering diaphragm, high/low needle, internal filter screen, and metering spring.
Sufficient for seasonal tune-ups when metal jets and metering levers remain clean and undamaged.
| Symptom | Probable Cause | Corrective Action |
|---|---|---|
| Engine bogs down upon acceleration | Stiff or hardened metering diaphragm; clogged high-speed jet | Install Master Kit (RK-21HR); inspect metering lever height |
| Engine idles fine, dies at full throttle | Partially clogged internal fine-mesh fuel strainer screen | Remove pump cover; replace screen with RK-21HR component |
| Fuel leaking into air box / flooding throat | Inlet needle worn or stuck open with fuel varnish | Replace inlet needle and clean brass seat |
| Engine runs lean or surges uncontrollably | Air leak through dried intake gasket or cracked impulse line | Install Gasket Kit (DG-1HR) and check fuel lines |