Rato R210

Rato R210The Rato R210 is a 212 cc (12.94 cu-in) single-cylinder air-cooled 4-stroke internal combustion general-purpose gasoline engine with horizontal shaft manufactured by Chongqing RATO Holding (Group) CO., LTD.

The Rato R210 engine has an OHV design; flat suction valve carburetor; recoil starter or electric starter, transistorized magneto ignition (TCI) system and centrifugal mechanical governor system.

A 70.0 mm (2.76 in) cylinder bore and 55.0 mm (2.16 in) piston stroke give the Rato R210 motor a total of 212 cc of displacement. Compression ratio rating is 9.0:1. It produced 7.0 HP of horsepower at 3,600 rpm and 12.0 N·m (1.22 kg·m, 8.85 ft·lb) of torque at 2,500 rpm.

General information

Engine Specifications
Model R210
Type 4-stroke, OHV, single cylinder
Displacement 212 cm 3 (12.94 cu-in)
Max. horsepower 7.0 HP at 3,600 rpm
Max. torque (crank PTO) 12.0 N·m (1.22 kg·m, 8.85 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)

Cylinder Block and Head

The Rato R210 engine has cast-iron cylinder liner, dual ball bearings and steel forged and hardened crankshaft.

Cylinder block
Compression ratio: 9.0:1
Bore x Stroke 70 X 55 mm (2.76 x 2.16 in)
Sleeve internal diameter 70.00 mm (2.7559 in)
Piston skirt outer diameter 69.985 mm (2.7553 in)
Number of piston rings (compression / oil): 2 / 1
Ring side clearance Top/Second 0.015-0.045 mm (0.0006-0.0018 in)
Ring end gap Top/Second 0.20-0.40 mm (0.008-0.016 in)
Oil 0.15-0.35 mm (0.006-0.014 in)
Ring width Top/Second 1.5 mm (0.060 in)
Oil 2.0 mm (0.079 in)
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 29.98 mm (1.180 in)
Cylinder Head
Warpage (limit) 0.10 mm (0.004 in)
Valve Arrangement: OHV
Valves: 2
Stem outer diameter (standard): INTAKE 5.48 mm (0.216 in)
EXHAUST 5.44 mm (0.214 in)
Cam height: INTAKE 27.7 mm (1.09 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)

Tightening torque specs

Tightening torque specs
Connecting rod bolt 13 Nm; 1.3 kg·m; 9.6 ft·lb
Oil dran plug 22 Nm; 2.2 kg·m; 16 ft·lb
Crankcase cover 28 Nm; 2.8 kg·m; 21 ft·lb
Flywheel subassembly 75 Nm; 7.5 kg·m; 55 ft·lb
Cylinder head subassembly 32 Nm; 3.2 kg·m; 23.6 ft·lb
Rocker shaft bolt 24 Nm; 2.4 kg·m; 18 ft·lb
Cylinder head cover 10 Nm; 1.0 kg·m; 7 ft·lb
Spark plug 28 Nm; 2.8 kg·m; 21 ft·lb
Ignition coil 10 Nm; 1.0 kg·m; 7 ft·lb

Service Information

Maximum speed 3800 ± 200 rpm
Cylinder compression 12.0 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
Main jet 0.85
Float height 13.7 mm (0.54 in)
Pilot screw opening 2-1/8 turns out
Ignition system
Ignition timing 20° B.T.D.C. (Fixed)
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 5.9-7.1 kΩ
Ignition coil air gap 0.4 ± 0.2 (0.016 ± 0.008)
ATTENTION! Dear visitors, this site is not a trading platform, an official dealer or a spare parts supplier, so we do not have any price lists or spare parts catalogs. We are an information portal and provide the technical specifications of gasoline and diesel engines.

We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.


  1. Hi ,
    I noticed that there are two yellow caps. One is oil dipstick and the other one is oil plug. To which one do we need to put in engin oil?

  2. im looking for an air filter for a poulan pro power series 174cc push behind lawn mower. the numbers locate at the base of the engine is Z870130 and the the next number was 171207B. the other number located was *RV175591440601* and the next number was *A1712003936*. have not been able to find replacement parts. for the lawn mower your assistantance will be appreciated. what about engine parts list also. so i can order parts. if needed. thanks.

    • IMHO yours lawn mower uses the Rato RV175 engine, but we are not a trading company, so we can`t help you with spare parts.

  3. Rato recommends 15W-40 motor oil. This is for diesel engines and not readily available. Why such a heavy duty oil?

  4. The 7.0HP (5,1kW) is only the PeakPower.
    Does someone know the continuous Power of the Engine?
    I want to use the engine as charging Generator using a Dual-Fuel Carburetor and a Truck Alternator.

    I asume, the RATO make 4,4kW continuous, hence I could calculate 4,4kW * 0,6 efficiency of the Alternator / 28 V = 94A.

    Since I do not want to run the Alternator under full load, but only 75%, the Alternator should be a 120A one.

    Since an Alternator has not very much Iron in it, the magnetic field is very fast saturated and the Alternator should have its 60% efficiency at full load, which mean, running an Alternator with only 75% of its rated power should increase the efficiency.

    Hence, if I am right, I could use a 140Ah one.

    Any comments and/or suggestions?

    I am in Estonia and you can contact me also directly under mma4miisu@gmail.com

    Have a nice day or whatever.

  5. I am trying to get a copy of a manual for the RATO 210cc pressure washer engine. Is there anyway you could send me a copy. Thank you.

  6. Where is bypass valve as won,t kick down when trigger is out and dies quick,at least this is 1 problem i read about

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