The Rato RV170 is a 173.2 cc (10.57 cu-in) single-cylinder air-cooled 4-stroke internal combustion general-purpose gasoline engine with vertical shaft, manufactured by Chongqing RATO Holding (Group) CO., LTD. The RV170 emgine is used for lawn mowers, pressure washers and tillers.
The Rato RV170 engine has a single-cylinder with a vertical shaft; an overhead valve (OHV) design; flat suction valve carburetor; recoil starter or electric starter, Capacitance Discharge Type or Inductance Discharge Type ignition system and centrifugal mechanical governor system.
A 70.0 mm (2.76 in) cylinder bore and 45.0 mm (1.77 in) piston stroke give the Rato RV170 motor a total of 173.2 cc of displacement. Compression ratio rating is 8.5±0.3:1. It produced 6.0 HP at 3,600 rpm of horsepower and 9.0 N·m (0.92 kg·m, 6.64 ft·lb) at 2,500 rpm of torque.
General information
| Engine Specifications | |
| Model | RV170 |
| Type | 4-stroke, OHV, single cylinder |
| Displacement | 173.2 cm 3 (10.57 cu-in) |
| Max. horsepower | 6.0 HP at 3,600 rpm |
| Max. torque (crank PTO) | 9.0 N·m (0.92 kg·m, 6.64 ft·lb) at 2,500 rpm |
| Carburetor | Flat suction valve carburetor |
| Cooling system | Forced-air |
| Ignition system | Capacitance Discharge Type or Inductance Discharge Type |
| 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) |
Cylinder Block and Head
| Cylinder block | ||
| Compression ratio: | 8.5:1 | |
| Bore x Stroke | 70 X 45 mm (2.76 x 1.77 in) | |
| Sleeve internal diameter | 70.00 mm (2.7559 in) | |
| Piston skirt outer diameter | 69.985 mm (2.53 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Connecting rod small end ID | 18.005 mm (0.7087 in) | |
| Connecting rod big end ID | 30.02 mm (1.182 in) | |
| Crankshaft crank pin outer diameter | 29.980 mm (1.180 in) | |
| Cylinder Head | ||
| Warpage (limit) | 0.10 mm (0.004 in) | |
| Valve Arrangement: | OHV | |
| Valves: | 2 | |
| Stem outer diameter (standard): | INTAKE | 5.480 mm (0.216 in) |
| EXHAUST | 5.440 mm (0.214 in) | |
| Cam height: | INTAKE | 27.70 mm (1.090 in) |
| EXHAUST | 27.75 mm (1.093 in) | |
| Valve spring free length: | 34.0 mm (1.3386 in) | |
| Camshaft journal diameter: | 13.984 mm (0.5505 in) | |
Service Information
| Engine | |
| Maximum speed | 3400 ± 100 rpm |
| Idle speed | 1900 ± 150 rpm |
| Cylinder compression | 14.0 kg/cm2 at 1400 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 | 4-stroke or an equivalent (SJ) |
| Recommended oil | SAE 10W-30, 15W-40 |
| Oil capacity | 0.6 L |
| Carburetor | |
| Main jet | #65 |
| Float height | 13.7 mm (0.54 in) |
| Pilot screw opening | 2-5/8 turns out |
| Ignition system | |
| Spark plug | NGK: BPR6ES |
| Spark plug gap | 0.7-0.8 mm (0.028-0.031 in) |
| Primary ignition coil resistance | 0.8-1.0 Ω |
| Secondary ignition coil resistance | 5.9-7.2 kΩ |
| Ignition coil air gap | 0.4 ± 0.2 (0.016 ± 0.008) |
Author:
I have a Mi T M pressure washer with your 170 series motor and need a new recoil starter and am unable to get a replacement localy. HELP
You can get parts for the engine depending on who uses the engine. I can get parts for my engine through the local mower shop. This mower shop can not look up the parts and order. However, since the engine is used by Poulan…Husqavarna…etc I can find the part number online…..google till something comes up and get the Poulan or husky part with the same part number. Cool huh?
I have a Rato RV170 lawn mower engine. I need a carborator bowl gasket. Cannot find anywhere. local mower shops are at a loss when finding a part number. This gasket broke when I removed the bowl. Would not run and needed to be cleaned. Now it runs great but leaks gass from bowl. Help me find this penny part please?????
I had the same problem. I used a bowl gasket for a Briggs. For $5 you can get “Bowl Float ” box BS#796611. In this box you will find 2 bowl gaskets. Use the small gasket…it does not fit( too small)but close. To fit… push the gasket down into grove with thumb. If you push hard enough the gasket will pinch into place into groove. It should stay put and be ready for your bowl. I did this and it works perfectly.
I am looking for a service/trouble shooting manual as I can’t seem to get the engine to run.
I need a piston push rod for a rato 7.0 rv170. I have not been able to search one out or even find a part number.
I am trying to install a off/on valve for the fuel line for a 170cc engine in my DR mower/trimmer. However, the fuel line is not 1/4, as almost all the valves are sized for. What size is the fuel line? btw, it is much smaller than 1/4