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
Type4-stroke, OHV, single cylinder
Displacement212 cm 3 (12.94 cu-in)
Max. horsepower7.0 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
CarburetorFlat suction valve carburetor
Cooling systemForced-air
Ignition systemTransistorized magneto ignition (TCI)
Lubricating systemSplash
Starting systemRecoil / electric starter
Stoping systemIgnition primary circuit ground
Fuel usedUnleaded gasoline (octane number 86 or higher)
PTO shaft rotationCounterclockwise (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 Stroke70 X 55 mm (2.76 x 2.16 in)
Sleeve internal diameter70.00 mm (2.7559 in)
Piston skirt outer diameter69.985 mm (2.7553 in)
Number of piston rings (compression / oil):2 / 1
Ring side clearanceTop/Second0.015-0.045 mm (0.0006-0.0018 in)
Ring end gapTop/Second0.20-0.40 mm (0.008-0.016 in)
Oil0.15-0.35 mm (0.006-0.014 in)
Ring widthTop/Second1.5 mm (0.060 in)
Oil2.0 mm (0.079 in)
Connecting rod small end ID18.005 mm (0.7087 in)
Connecting rod big end ID30.02 mm (1.182 in)
Crankshaft crank pin outer diameter29.98 mm (1.180 in)
Cylinder Head
Warpage (limit)0.10 mm (0.004 in)
Valve Arrangement:OHV
Stem outer diameter (standard):INTAKE5.48 mm (0.216 in)
EXHAUST5.44 mm (0.214 in)
Cam height:INTAKE27.7 mm (1.09 in)
EXHAUST27.75 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 bolt13 Nm; 1.3 kg·m; 9.6 ft·lb
Oil dran plug22 Nm; 2.2 kg·m; 16 ft·lb
Crankcase cover28 Nm; 2.8 kg·m; 21 ft·lb
Flywheel subassembly75 Nm; 7.5 kg·m; 55 ft·lb
Cylinder head subassembly32 Nm; 3.2 kg·m; 23.6 ft·lb
Rocker shaft bolt24 Nm; 2.4 kg·m; 18 ft·lb
Cylinder head cover10 Nm; 1.0 kg·m; 7 ft·lb
Spark plug28 Nm; 2.8 kg·m; 21 ft·lb
Ignition coil10 Nm; 1.0 kg·m; 7 ft·lb

Service Information

Maximum speed3800 ± 200 rpm
Cylinder compression12.0 kg/cm2 at 1400 rpm
Valve clearance
Intake valve clearance0.15±0.02 mm (0.006±0.001 in)
Exhaust valve clearance0.20±0.02 mm (0.008±0.001 in)
Oil system
Oil type4-stroke or an equivalent (SJ)
Recommended oilSAE 10W-30, 15W-40
Oil capacity0.6 L
Main jet0.85
Float height13.7 mm (0.54 in)
Pilot screw opening2-1/8 turns out
Ignition system
Ignition timing20° B.T.D.C. (Fixed)
Spark plugNGK: BPR6ES
Spark plug gap0.7-0.8 mm (0.028-0.031 in)
Primary ignition coil resistance0.8-1.0 Ω
Secondary ignition coil resistance5.9-7.1 kΩ
Ignition coil air gap0.4 ± 0.2 (0.016 ± 0.008)
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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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