The Rato R100 is a 98 cc (6.0 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 R100 engine has an OHV design; flat suction valve carburetor; recoil starter or electric starter and transistorized magneto ignition (TCI) system.
A 56.0 mm (2.2 in) cylinder bore and 40.0 mm (1.60 in) piston stroke give the Rato R100 motor a total of 98 cc of displacement. Compression ratio rating is 8.5±0.3:1. It produced 3.0 HP of horsepower at 3,600 rpm and 4.7 N·m (0.48 kg·m, 3.46 ft·lb) of torque at 2,500 rpm.
General information
Engine Specifications
Model
R100
Type
4-stroke, OHV, single cylinder
Displacement
98 cm 3 (6.0 cu-in)
Max. horsepower
3.0 HP at 3,600 rpm
Max. torque (crank PTO)
4.7 N·m (0.48 kg·m, 3.46 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
Cylinder block
Compression ratio:
8.5:1
Bore x Stroke
56 X 40 mm (2.2 x 1.6 in)
Sleeve internal diameter
56.00 mm (2.2047 in)
Piston skirt outer diameter
55.965-55.985 mm (2.2033-2.2041 in)
Number of piston rings (compression / oil):
2 / 1
Ring side clearance
Top/Second
0.03-0.07 mm (0.0012-0.0027 in)
Ring end gap
Top/Second
0.15-0.30 mm (0.006-0.012 in)
Oil
0.1-0.6 mm (0.0040-0.023 in)
Ring width
Top/Second
1.5 mm (0.060 in)
Oil
2.0 mm (0.079 in)
Connecting rod small end ID
14.011-14.022 mm (0.5516-0.5520 in)
Connecting rod big end ID
23.02-23.03 mm (0.9063-0.9066 in)
Crankshaft crank pin outer diameter
22.975-22.985 mm (0.9045-0.9049 in)
Cylinder Head
Warpage (limit)
0.10 mm (0.004 in)
Valve Arrangement:
OHV
Valves:
2
Stem outer diameter (standard):
INTAKE
5.465-5.480 mm (0.2151-0.2157 in)
EXHAUST
5.445-5.460 mm (0.2143-0.2149 in)
Cam height:
INTAKE
29.4 mm (1.1575 in)
EXHAUST
29.4 mm (1.1575 in)
Valve spring free length:
25.0 mm (0.9842 in)
Tightening torque specs
Tightening torque specs
Connecting rod bolt
12 Nm; 1.2 kg·m; 9 ft·lb
Oil dran plug
22 Nm; 2.2 kg·m; 16 ft·lb
Crankcase cover
12 Nm; 1.2 kg·m; 9 ft·lb
Flywheel subassembly
55 Nm; 5.5 kg·m; 41 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
Engine
Maximum speed
3850 ± 200 rpm
Idle speed
1550 ± 150 rpm
Cylinder compression
9.2 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
0.35 L
Ignition system
Spark plug
NGK:BPR6ES
Spark plug gap
0.7-0.8 mm (0.028-0.031 in)
Author:Sergei WersAbout: 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.
1 Comment
The spark plug mentioned above is wrong,NGK CR5HSB is the correct plug for this machine.BPR6ES will not fit,please edit this fault.
The Rato R100 is a 98 cc (6.0 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.
Author:
The spark plug mentioned above is wrong,NGK CR5HSB is the correct plug for this machine.BPR6ES will not fit,please edit this fault.