Evinrude 112 SPL Specifications
| Engine Model: Evinrude 112 SPL |
| Engine Type: 2-stroke 4-cylinder gasoline outboard engine |
| Total Displacement: 105.4 cu.in (1.7 L) |
| Rated Engine Power: 112 Hp (83 kW) at 5000 rpm |
| Fuel System: Float-feed carburetors |
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The Evinrude 112 SPL represents a distinct
chapter in the outboard manufacturer's history, occupying a unique
position in the Hp lineup as a "Special" model derived from the
60-degree V4 loop-charged engine family. Produced primarily throughout
the mid-1990s and into the early 2000s, this powerplant was engineered
as a value-oriented alternative to the more feature-rich OceanPro and XP
series, offering boaters a dependable, straightforward outboard without
some of the premium amenities that increased cost and complexity.
The SPL designation indicated a model stripped of certain features, most
notably the VRO oil injection system, though later production years
often incorporated power trim and tilt as standard equipment. This
approach resulted in an engine highly regarded for its mechanical
simplicity, ease of service, and robust power delivery across a wide
operating range.
The 112 SPL utilizes a 60-degree V-block configuration, distinguishing
it from the older 90-degree V4 designs that preceded it. This narrower
angle creates a more compact, lighter powerhead while maintaining
excellent power-to-weight ratio characteristics. The loop-charged
induction system represents a sophisticated approach to two-stroke
scavenging, where precisely machined ports in the cylinder walls and
specially designed piston crowns direct the incoming fuel charge in a
looping pattern that efficiently expels exhaust gases while maximizing
cylinder filling.
This design contributes to the engine's strong torque curve and fuel
efficiency relative to cross-flow scavenged designs. As an SPL model,
this engine was marketed as a "Special" value package, often featuring
simplified trim packages, reduced decorative elements, and the
deliberate omission of the Variable Rate Oiling system in favor of
traditional pre-mix operation.
The Evinrude 112 SPL delivers 112 Hp measured at the propeller shaft,
representing the peak output of this 60-degree V4 platform. The engine
displacement measures 105.4 cubic inches, which converts to 1.7 liters,
providing the foundation for its power production capabilities. The bore
and stroke dimensions are consistent with other members of this engine
family, measuring 3.601 inches for the bore and 2.588 inches for the
stroke, creating an oversquare configuration that favors higher
operating RPM capabilities while maintaining reasonable piston speeds
for durability.
The induction system utilizes carburetors feeding a loop-charged
combustion process, with individual carburetors serving each cylinder
for precise fuel metering. The ignition timing specification requires
setting the initial timing to 28 deg before top dead center at 5000 RPM,
ensuring proper combustion phasing for maximum power output and
efficiency. The engine incorporates a gear ratio of 2.00:1 in the lower
unit, providing optimal torque multiplication for planing hulls and
load-carrying ability.
The SPL series engines utilize 13-spline propeller shafts,
distinguishing them from some premium models that may have used
different spline configurations. The weight range for this powerplant
falls between approximately 350 and 370 lbs, with variations depending
on the specific model year and included features such as power trim and
tilt systems. The shaft length was available in the 25-inch extra-long
configuration, making this engine suitable for boats with higher
transoms or those requiring deeper propeller submersion in rough water
conditions.
The Evinrude 112 SPL cylinder block is a precision-machined aluminum
casting featuring the distinctive 60-degree V configuration that houses
four cylinders in a compact, rigid structure. This architecture provides
exceptional strength while minimizing overall engine dimensions and
weight. The cylinder bores are machined directly into the aluminum block
and feature either chrome-plated or NICOM-coated surfaces, providing
excellent wear resistance and heat transfer characteristics without
requiring separate cast-iron cylinder liners.
The timing and duration of port opening and closing are determined
solely by piston position, creating an elegantly simple yet highly
effective method of controlling gas flow. The loop-charged design
incorporates multiple transfer passages that direct the incoming
fuel-air charge in a manner that promotes efficient scavenging and
complete combustion.
The cylinder heads bolt to each bank of the block, sealing the
combustion chambers at the top of each cylinder. These heads contain the
combustion chamber recesses and provide mounting points for the spark
plugs. The cooling system incorporates thermostats housed in the
cylinder heads, regulating operating temperature for optimal efficiency
and component longevity.
The power head disassembly procedures detailed in service manuals
specify the proper sequence for cylinder head removal, enabling access
to the pistons, rings, and cylinder walls for inspection,
decarbonization, or major overhaul operations.
The fuel system on the Evinrude 112 SPL employs carburetion as the
primary induction method, with each cylinder served by an individual
carburetor for precise fuel distribution. These carburetors are of the
float-feed variety, incorporating calibrated jets, idle circuits, and
high-speed circuits to meter fuel across the entire operating range. The
design of the SPL models deliberately omitted the VRO oil injection
system found on premium variants, requiring the operator to pre-mix
two-stroke oil with the gasoline in the main fuel tank at a 50:1 ratio.
The fuel delivery circuit begins at the boat-mounted fuel tank, where an
anti-siphon valve prevents fuel from siphoning should a line rupture. A
portable fuel tank may utilize a quick-connect fitting at the engine
cowling. The fuel line incorporates a primer bulb that must be squeezed
to fill the carburetor bowls before starting a cold engine. A
diaphragm-type fuel pump, driven by crankcase pressure pulses, draws
fuel from the tank and delivers it to the carburetors under pressure.
The pump incorporates check valves and a diaphragm that flexes with
pressure changes to move fuel through the system.
The carburetors require periodic cleaning and rebuilding, particularly
if the engine has been stored for extended periods or if ethanol-blended
fuels have contributed to varnish formation. The idle mixture and idle
speed adjustments must be performed with the engine at operating
temperature, using a tachometer for accuracy. An important component is
the air silencer base gasket, which seals the airbox to the carburetors;
a deteriorated gasket can allow raw fuel to accumulate in the lower
cowling, as the airbox drain hose recirculates this excess fuel to the
crankcase.
The Evinrude 112 SPL lubrication system follows the total-loss principle
inherent to two-stroke engine design, where oil mixed with the fuel
provides lubrication to the crankshaft bearings, connecting rod
bearings, piston pins, and cylinder walls before being consumed during
combustion. The SPL designation specifically indicates the absence of
the Variable Rate Oiling automatic injection system, simplifying the
engine by eliminating the oil reservoir, injection pump, interconnecting
hoses, and associated warning components.
For pre-mix operation, the operator must ensure proper oil-to-fuel ratio
at every refueling. The recommended mixture for break-in and normal
operation is 50:1, requiring one pint of TCW-3 certified two-stroke
outboard oil for every six gallons of gasoline. This ratio provides
adequate lubrication under all operating conditions, from slow trolling
to wide-open throttle running. Using oils meeting the TCW-3
specification is essential, as these formulations contain the correct
additive packages for water-cooled outboard operation, including
detergents to keep rings free, corrosion inhibitors to protect internal
components during storage, and ashless chemistry to minimize combustion
deposits.
The absence of an automatic oiling system on SPL models eliminates a
potential failure point and reduces maintenance requirements, though it
places greater responsibility on the operator to maintain correct
mixture ratios. This design choice aligns with the "Special" value
positioning, appealing to boaters who prefer the simplicity and
reliability of traditional pre-mix operation or who operate in remote
areas where VRO system service might be difficult to obtain.
The cooling system on the Evinrude 112 SPL employs a
positive-displacement water pump to circulate cooling water through the
engine's water jackets. The pump, located in the lower unit above the
gearcase, uses a flexible rubber impeller mounted on the driveshaft. As
the driveshaft rotates, the impeller vanes flex and create suction,
drawing water through the gearcase inlet screens and pushing it upward
through the water tube into the power head.
Once inside the engine, cooling water enters the cylinder block water
jackets surrounding the cylinders. Internal deflectors and cast passages
direct water flow to the hottest areas, including the exhaust ports and
combustion chamber surfaces. The water then rises to the cylinder heads,
where thermostats regulate flow based on engine temperature. When the
engine is cold, the thermostats remain closed, forcing water to
circulate through a bypass passage, allowing rapid warm-up to operating
temperature. Once the thermostats open at their rated temperature, full
water flow passes through the heads and exits through the exhaust system
or the tell-tale indicator.
The tell-tale, a small hose exiting the engine cowling, provides a
visual indication of water pump operation. A steady stream of water
confirms that the pump is moving water and the cooling system is
pressurized. Service manuals emphasize regular water pump impeller
replacement, every one to three years depending on usage, as a critical
maintenance item. A failed impeller can result in rapid engine
overheating and severe power head damage. The cooling system also
incorporates a pressure control valve that regulates water pressure at
high speeds, preventing excessive pressure that could damage gaskets or
seals.
| Mid Section and Lower Unit |
The midsection of the Evinrude 112 SPL serves multiple functions,
housing the exhaust passage that carries combustion gases from the power
head to the lower unit, providing structural support for the engine, and
incorporating the motor mounts that isolate vibration from the boat
hull. The 25-inch extra-long shaft length accommodates higher transoms
common on offshore boats, deep-V hulls, and vessels designed for rough
water operation where keeping the propeller submerged during wave action
is critical.
The lower unit contains the gearcase, which houses the forward, neutral,
and reverse gears, the driveshaft, the propeller shaft, and the water
pump assembly. The gear ratio of 2.00:1 means the driveshaft rotates
twice for each complete revolution of the propeller shaft, providing
mechanical advantage that allows the engine to operate in its optimal
power band while spinning a larger, more efficient propeller at lower
RPM. This ratio is well-suited for planing hulls requiring substantial
torque to reach plane and maintain cruising speeds.
The lower unit incorporates a sacrificial zinc anode to protect against
galvanic corrosion, a trim tab that can be adjusted to counteract
propeller torque steering effects, and a skeg that protects the
propeller and aids in directional stability. The gearcase requires
periodic oil changes using high-quality marine gear lubricant, with
service intervals specified in the maintenance schedule. Pressure and
vacuum testing of the gearcase, as outlined in service manuals, verifies
the integrity of seals and gaskets, preventing water intrusion that
could lead to gear and bearing failure.
The Evinrude 112 SPL, particularly in later production years,
incorporated power trim and tilt systems that allowed the operator to
adjust engine angle for optimal performance. These hydraulic systems
utilize an electric motor driving a hydraulic pump, which pressurizes
fluid to extend or retract the trim cylinders. The trim function
operates through a limited range of motion, up to approximately 20 deg,
allowing fine adjustments to boat attitude while underway. Trimming the
engine inward pushes the bow down for quicker planing and improved hole
shot, while trimming outward raises the bow for increased speed and
efficiency in calm water.
The tilt function extends the cylinders beyond the trim range, lifting
the engine completely out of the water for trailering, launching,
beaching, or performing maintenance. The system incorporates manual
release valves that permit manual raising or lowering should the
electric system fail or during servicing. Service manuals provide
comprehensive troubleshooting procedures for common trim and tilt
issues, including electrical faults, hydraulic leaks, and mechanical
binding.
Common problems encountered with these systems include unresponsive
operation due to electrical switch failure, corroded wiring connections,
or hydraulic pump motor failure. Hydraulic issues may include fluid
leaks from cylinder seals, air ingestion causing spongy operation, or
internal valve malfunctions. Regular maintenance includes checking fluid
levels, inspecting for leaks, and verifying proper operation of the
manual release mechanism. The trim and tilt system represents one of the
few areas where the SPL models differ from base engines, as later
production years often included this feature despite the stripped-down
positioning of the series.
Propeller selection for the Evinrude 112 SPL requires careful
consideration of boat weight, hull design, and intended usage to achieve
optimal performance. The engine's 2.00:1 gear ratio and 13-spline
propeller shaft configuration determine the compatible propeller types.
Common propeller sizes utilized with this powerplant include 13 3/4 x 15
and 13 x 19 configurations, with the appropriate choice depending on
load conditions and performance priorities.
The 13 3/4 x 15 propeller represents a lower pitch option suited for
heavier boats, those carrying substantial loads, or operators
prioritizing hole shot and planing ability over top speed. This
configuration allows the engine to reach its recommended operating RPM
range more easily under load, reducing strain on the power head and
providing stronger acceleration for water sports or quick planing.
Conversely, the 13 x 19 propeller offers higher pitch for lighter boats
or operators seeking maximum top speed, allowing the engine to achieve
higher boat speeds at similar RPM.
Proper propeller selection requires verifying that the engine achieves
its recommended full-throttle operating range, 5500 RPM, with a normal
load. An over-propped condition, where pitch is too high, prevents the
engine from reaching proper RPM, causing lugging, increased carbon
buildup, and potential engine damage. An under-propped condition, where
pitch is too low, allows the engine to exceed maximum rated RPM, risking
mechanical failure from overspeed. The trim tab adjustment, located on
the gearcase above the propeller, may require repositioning when
changing propeller types to counteract steering torque effects. Factors
such as the presence of a hydrofoil can significantly impact
performance; removal of such devices often improves RPM and speed by
reducing drag.
The Evinrude 112 SPL presents specific physical dimensions that
influence boat fitment and trailering considerations. The overall weight
ranges from approximately 350 to 370 lbs, with the variation
attributable to differences in included equipment such as power trim and
tilt mechanisms, alternator output capacity, and specific model year
design changes. This weight class places the engine within the capacity
of most standard outboard brackets and transoms designed for 100-115 Hp
outboards.
The 25-inch extra-long shaft length represents the distance from the
transom mounting clamp to the anti-ventilation plate, accommodating
boats with transom heights designed for this shaft length. Proper
mounting height places the anti-ventilation plate approximately even
with or slightly above the boat bottom, allowing optimal water flow to
the propeller while minimizing drag. The overall width of the engine is
determined by the 60-degree V-block configuration within the cowling,
which creates a relatively compact profile suitable for dual-engine
installations where multiple outboards mount side-by-side on the
transom.
The height from the mounting clamp to the top of the engine cowling
varies by model year but generally falls within the range typical for V4
outboards of this Hp class. These dimensional considerations affect
trailer selection, storage requirements, and the ability to fit under
standard boat covers or in enclosed spaces. The engine's physical size
also influences the leverage forces on the transom and the clearance
required for tilting the engine fully up during trailering or beaching
operations.
Systematic maintenance ensures the longevity and reliability of the
Evinrude 112 SPL, with service manuals providing detailed schedules and
procedures. Routine maintenance tasks include lubrication of all pivot
points, steering components, and tilt tube with marine-grade grease at
specified intervals. The steering system requires particular attention,
as corrosion in the tilt tube can cause stiff steering and eventual
seizure.
The lower unit gear oil requires periodic inspection and replacement,
with the manufacturer recommending annual changes or every 100 hours of
operation, whichever occurs first. Checking the gear oil involves
removing the lower fill and vent plugs and observing the oil condition.
Milky or discolored oil indicates water intrusion, requiring immediate
investigation and seal replacement. The water pump impeller demands
replacement every one to three years, as aged rubber can crack, shed
vanes, or lose pumping efficiency, leading to overheating.
Spark plug inspection and replacement at recommended intervals maintains
ignition performance and fuel efficiency. The correct heat range and gap
specifications must be observed, with the service manual listing
approved plug types. Carburetor synchronization and linkage adjustments
ensure proper fuel delivery across all cylinders and smooth operation
from idle to wide-open throttle. The fuel system requires attention to
fuel line condition, primer bulb integrity, and periodic carburetor
cleaning to address the effects of ethanol-blended fuels and normal
varnish formation.
Winterization procedures for the 112 SPL include adding fuel stabilizer
to the tank, warming the engine on a flusher, fogging the engine by
spraying fogging oil into the carburetor intakes until the engine
stalls, removing and fogging the spark plug cylinders, greasing all
fittings, and draining and refilling the lower unit gear oil. The engine
features a schrader valve on the fuel primer solenoid that accepts a
specialized hose from fogging oil aerosol cans, simplifying the fogging
process.
The cylinder head bolts require careful torquing to ensure even clamping
pressure on the head gasket without distortion of the cylinder head or
block. The specified torque for these critical fasteners falls within
the range of 18 to 22 lb-ft, converted to 24 to 30 Nm. Following a
warm-up period and engine cool-down, retorquing the head bolts to
specification compensates for gasket compression and thermal cycling.
The flywheel nut, securing the flywheel to the crankshaft taper,
requires substantial torque to maintain this critical connection against
the forces of ignition and rotation. The specified torque for this
fastener is 100 to 105 lb-ft, or 135 to 142 Nm. Achieving this torque
with a quality torque wrench and verifying the flywheel is fully seated
on the taper prevents shearing of the flywheel key and maintains proper
ignition timing.
Connecting rod bolts, fastening the rod caps to the rods, must be
torqued to specifications that ensure proper bearing clearance and clamp
load without exceeding the fastener's elastic limit. These fasteners
require 60 to 65 lb-in, converted to 6.8 to 7.3 Nm. The use of a torque
wrench capable of accurate readings in this lower range is essential, as
over-torquing can stretch or break bolts, while under-torquing can lead
to bearing failure.
Spark plug installation torque of 15 to 18 lb-ft, or 20 to 24 Nm,
ensures proper compression seal and heat transfer without risking thread
damage in the aluminum cylinder head. The gearcase mounting nuts,
securing the lower unit to the midsection, require torquing to 30 to 35
lb-ft, or 41 to 47 Nm, maintaining the compression on the water tube
grommet and gearcase seal.
The Evinrude 112 SPL finds appropriate application on a variety of boat
types where its 112 Hp output matches hull requirements and performance
expectations. Deep-V center console boats in the 18 to 20-foot range
represent a natural application, where the engine's power provides
confident operation in coastal waters and offshore fishing grounds. The
extra-long shaft configuration suits these boats particularly well,
maintaining propeller immersion in following seas and rough conditions.
Dual console and bowrider family boats from 17 to 19 feet accommodate
this power level effectively, providing acceleration for water sports,
cruising capability for family outings, and reliability for day-long
adventures. The SPL model's straightforward design appeals to boaters
who value simplicity and ease of maintenance over premium features,
making it suitable for rental fleets, fishing guides, and recreational
users who operate in remote areas.
Aluminum fishing boats in the 18 to 20-foot range, including those used
for Great Lakes trolling, walleye fishing, and multi-species angling,
match well with the 112 SPL's power and weight characteristics. The
engine's torque enables these lighter hulls to achieve excellent
performance while maintaining fuel efficiency.
A specific example includes the 1995 Sylvan 16 Pro Select aluminum
fishing boat, which with a 1994 Evinrude 112 SPL achieved WOT RPM of
5500 and speeds of 42 mph with proper propeller selection and setup.
Classic hull designs and re-powered boats benefit from the engine's
modern 60-degree architecture and loop-charged efficiency, bringing
updated reliability and parts availability to older vessels. The 112
SPL's production span through the early 2000s ensures continued parts
support for these applications through marine dealerships and
aftermarket suppliers.
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