The Rato R670 is a 670 cc (40.9 cu-in) V-twin cylinder air-cooled four-stroke internal combustion small gasoline engine with horizontal shaft manufactured by Chongqing RATO Holding (Group) CO., LTD. The R670 is used for generators, hot water pressure washers, agricultural equipment.
The Rato R670 engine has an OHV (overhead valve) design with 90° V-twin cylinders; flat suction valve carburetor; recoil starter or electric starter, transistorized magneto ignition (TCI) system, and centrifugal mechanical governor system.
The Rato R670 motor has a 78.0 mm (3.07 in) cylinder bore and 70.0 mm (2.76 in) piston stroke with a compression ratio of 8.1:1. It produced 23.0 HP at 3,600 rpm of horsepower and 45 N·m (4.58 kg·m, 19.9 ft·lb) at 2,500 rpm of torque.
General information
| Engine Specifications | |
| Model | R670 |
| Type | 4-stroke, OHV, 90° V-twin |
| Displacement | 670 cm 3 (40.9 cu-in) |
| Max. horsepower | 23.0 HP at 3,600 rpm |
| Max. torque (crank PTO) | 45 N·m (4.58 kg·m, 19.9 ft·lb) at 2,500 rpm |
| Carburetor | Flat suction valve carburetor |
| Cooling system | Forced-air |
| Ignition system | Transistorized magneto ignition (TCI) |
| Lubricating system | Splash |
| Starting system | Recoil / electric starter |
| Stoping system | Ignition primary circuit ground |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| PTO shaft rotation | Counterclockwise (from PTO shaft side) |
Service Information
| Engine | |
| Maximum speed | 3,850 ± 100 rpm |
| Idle speed | 1,400 ± 150 rpm |
| Cylinder compression | 6.0-8.0 kg/cm2 (85-114 psi) at 500 rpm |
| Valve clearance | |
| Intake valve clearance | 0.15±0.02 mm (0.006±0.001 in) |
| Exhaust valve clearance | 0.20±0.02 mm (0.008±0.001 in) |
| Oil system | |
| Oil type | API SG or SF |
| Recommended oil | SAE 10W-30 |
| Oil capacity | 1.90 L |
| Oil change interval | Every 6 month or 100 Hrs. |
| Ignition system | |
| Spark plug | NGK: ZGR5A DENSO: J16CR-U |
| Spark plug gap | 0.7-0.8 mm (0.028-0.031 in) |
I have a Caterpillar RP12000e generator with the RATO 670 engine and I’ve been searching high and low where I can purchase a FUEL SHUT OFF SOLENOID. Solenoid not activating when ignition is turned on. Checked current on lead to solenoid connector and have good 12 volts. SO can only assume solenoid took a dump. Any idea who sells them? Been searching for 3 weeks! Generator left me high and dry during hurricane Helene.