Small Gasoline Engines Engine
Define Engine:
Are these engines?
A. YES: An engine or motor is a machine designed to convert energy into useful mechanical motion Engine
Define Engine:
What is the primary difference between these engines and modern engines? Heat Engine
How does modern engines use heat? Two general categories based on how the heat is used.
External combustion engine
Internal combustion engine Internal Combustion Engines Small Engine Development
Year Engine Designer/developer 1680 Gunpowder Christian Huygens 1698 Savery Pump Thomas Saverly 1712 Newcomen Steam Thomas Newcomen 1763 Watt Double-acting steam James Watt 1801 Coal gas/electric ignition Eugene Lebon 1802 High pressure steam Richard Trevithick 1859 Pre-mixed fuel and air Etienne Lenoir 1862 Gasoline Nikolaus Otto 1876 Four cycle gasoline Nikolaus Otto 1892 Diesel Rudolf Diesel 1953 Die-cast aluminum B&S Internal Combustion--Intro
Engine designs can be classified by: 1. Size 2. Ignition system 3. Strokes per cycle 4. Cylinder orientation 5. Crankshaft orientation 6. Control system 7. Cooling system 1. Engine Size
Engines are available in a wide range of sizes.
Industry definition: “A small engine is an internal combustion engine rated up to 25 horsepower.” 1. Size - Largest The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today.
The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1,820 liters) and produces 7,780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version. 1. Size - Smallest
• Not much bigger than a stack of pennies, the "mini engine" is the first engine of its size to deliver power on a continuous basis.
• Currently will produce 2.5 watts of electricity (0.00335 hp).
• Uses 1/2 fluid ounce of fuel per hour 3. Cycles
Four stroke
Two stroke
Name one common use for each type. 4. - Cylinder Orientation There is no limit on the number of cylinders that a small engines can have, but it is usually 1 or 2.
Four common cylinder orientations for small engines Vertical Slanted Horizontal Multi position
Give an example of a use for each. 4. - Cylinder Orientation—cont.
Three common cylinder configuration in multiple cylinder engines:
V Horizontally opposed
In-line
Can you identify one application for each of these types? 5. Crankshaft Orientation
Small gas engines use three crankshaft orientations:
Multi-position Horizontal
Vertical
Identify a use for each one. 6. Controls Traditionally engines are controlled by mechanical means. Governor Throttle Choke Etc. Honda has an engine with an electronic control unit (ECU).
ECU - Electronic Control Unit – Monitors and controls engine functions including Throttle, Choke, Ignition Timing, Oil Alert – Offers programmable governor and throttle modes for unprecedented flexibility and diagnostic LED for trouble shooting – Stepper motors precisely control throttle and choke position 7. Cooling System
Small engines use two types of cooling systems:
– Air
– Water
Why does an internal combustion engine need a cooling system?
Why what are the advantages and disadvantages of both systems? 7. Cooling system—cont.
Convection – Transfer of heat via transfer from one material in contact with another (Water boiling in a pan)
Conduction – Transfer of heat via movement within the material being heated
Radiation – Transfer of heat through the air 7. Cooling System—cont.
How is excess heat moved within and removed from the engine? 7. Cooling system—cont.
Q. Why is it important to understand the transfer of heat in a small engine?
A. Heat is one of the single biggest hazards to an engine. Why?
Internal Temperatures can reach 3600 Degrees F Exhaust Manifolds can reach 1800 Degrees F
***Aluminum melts at around 1200 Degrees F*** ***Cast Iron melts at around 2300 Degree F***
The cooling system of an Aluminum Engine is critical to its efficient operation and life. Cooling System
So how does a Small Engine Cool? Conduction/Convection/Radiation?
A. All of the above, and all three methods must be maintained for efficient operation.
Fuel/Air Ignition by Convection heats the engine, The Cylinder (mostly) transfers heat to cooling fins by Conduction and the flywheel/shroud transfer heat by Radiation.
Example of a cooling system failure include scared cylinder walls, valve warpage, broken crank, connecting rod or cam, and engine seizure. Cooling System
Servicing Air-Cooled Engines
Most small, single-cylinder engines are cooled by a stream of air developed by fan blades on the flywheel. The air stream is deflected around the cylinder and cylinder head by a metal or plastic cover called a shroud. Additional engine heat is dissipated through cooling fins around the cylinder. Servicing air-cooled systems is generally very easy but often overlooked. Here's how to service an air-cooled system:
Step 1: Periodically (annual inspection) remove the shroud from around the engine flywheel and inspect the inside for debris.
Step 2: With the shroud removed, visually inspect the flywheel blades for debris and damage. NOTE: Broken Flywheel Blades DO NOT move air!
Step 3: Visually inspect cooling fins on the cylinder and cylinder head. Use a wooden stick or clean paintbrush to clear away any debris. When the engine is cool, wipe the surfaces of the cooling fins, cylinder, and cylinder head with a cloth. Remember that even the tip of a cooling fin can have a surface temperature of over 100 degrees Farenheit (38 degrees Celsius). NOTE: Broken cooling fins CAN NOT transfer heat. Oil and grease on a cooling fins WILL PREVENT efficient transfer of heat.
Step 4: Replace the shroud over the flywheel and cylinder. Make sure the flywheel blades aren't striking the shroud. Liquid Cooling Systems
Circulating fluid (coolant) assists in removing heat of combustion Coolant is usually a mixture of antifreeze and water Coolant must be changed periodically to remove corrosion and replace additives
UT Extension Antifreeze Types
Ethylene glycol (green) Propylene glycol (green) Long-Life ethylene glycol (orange)
UT Extension Replacing Antifreeze*
Regular antifreeze – Drain, flush and replace every one to two years Long life antifreeze – Drain, flush, replace every 5 years or 100,000 to 150,000 miles * Additives include corrosion inhibitors, sealers, water pump lubricant, heat transfer compounds
UT Extension Toxicity
Ethylene glycol – very toxic Propylene glycol – non toxic* * Will be slightly toxic after use in cooling system – picks up contaminants such as lead, mercury
UT Extension Freeze Protection
Pure antifreeze – minus 9 F 50% water + 50% antifreeze – minus 34 F 30% water + 70% antifreeze – minus 84 F
UT Extension Boil-Over Protection
Pure antifreeze – 98 degrees F 50% water + 50% antifreeze – 265 F 30% water + 70% antifreeze – 282 F
UT Extension Mixing Anti-Freezes
Regular antifreeze (green) and Long-life antifreeze (orange) cannot be mixed !!!!!!! Regular antifreeze contains alkaline corrosion inhibitors Long life antifreeze contains organic acid corrosion inhibitors
UT Extension Physical Principles of Engines Energy
Energy is the capacity for doing work.
What are the two forms of energy?
Which form are these? Physical Principles of Engines
Intake
Compression
Power
Exhaust Physical Principles of Engines
Intake System
• Air Intake
• Fuel Intake Main Causes of Premature Small Engine Failure (Short Engine Life)
UT Extension Dirt
60% to 70% of all failures are caused by dirt* getting into engine
*Dust, insects, bits of grass, etc.
UT Extension Service air filter on a regular basis (usually once a season)
Service more often under dusty or adverse conditions
UT Extension For every gallon of gasoline used, the air filter must clean 10,000 to 11,000 gallons of air
UT Extension Air Filter – Paper Type
UT Extension Carburetor
UT Extension Failure to use clean, fresh fuel
Dirty fuel tank Dirty fuel can Dirty funnel Trash/dirt around fuel cap
UT Extension Install a fuel filter on fuel line if not factory equipped
UT Extension Fuel Filter
UT Extension Use a suitable fuel container to prevent fuel contamination and insure safety
Metal cans will eventually rust inside Plastic containers will not rust Use a funnel with mesh filter
UT Extension Can Good Plastic Fuel
UT Extension Failure to use proper fuel
Unleaded fuel is cleaner burning Choose proper fuel octane level Do not use fuel containing alcohol Use lead substitutes if 1974 or older
UT Extension Operating tips to extend engine life
Let engine idle for two minutes before stopping Never stop under load Avoid stalls and sudden impacts
UT Extension Small Engines
Ignition System Ignition-Power Stroke
Spark ignition
Compression ignition
What is the primary difference? 2. Ignition
Spark ignition
Compression ignition
What is the primary difference? Ignition System Function
Ignite the fuel and air mixture at the proper time. Advance and retard the ignition timing as needed. “Ground-out” the ignition system so the engine will stop running. Ignition Parts Battery type
Battery Ignition coil Ignition switch Low voltage wires (battery volts) Ignition Pick-up ( points or electronic) High Voltage wire(s) Spark Plug Ignition Principles
Electromagnetic Induction How does the Ignition Coil work? Primary winding: creates a magnetic field by running current through it. When we open the circuit current stops, and the electromagnetic field collapses. Ignition Coil Parts
Primary Winding Secondary Winding Iron Core Switching current in Primary
Breaker Points and condenser Points: Mechanical switch Condenser: makes the switch last longer so the points don’t “ burn out”
Self Induction
When you run current through a coil of wire, you create a magnetic field. When you “open” the current flow through that coil of wire you collapse that magnetic field into itself. Coil output
You produce about 1 volt per turn of wire Example: 225 turns of coil wire can produce up to 225 volts, however your current output drops at the same rate that you voltage increases. Induction Principle
Coil of wire + Current flow = Magnetic field Magnetic field + Coil of wire = Current flow *Remember you must have the magnetic field or the coil of wire moving to have induction Mutual Induction
When you have two coils of wire in one housing. You create a magnetic field with one coil (primary) You collapse the magnetic field into both coils Primary and Secondary Mutual Induction Output
You can increase or decrease voltage output of your induction coils, by changing the primary and secondary windings ratio. Example: primary 250 turns secondary 20,000 turns Secondary output could reach up to 20,000 volts!! This is called a Step-up transformer Continued
250 turns primary and 20 turns secondary. Maximum output 20 volts. This is a “step-down” transformer. Magnetron Coil
The magnetron coil actually contains 3 separate coils of windings. In addition to the primary and secondary windings, there is a 3rd winding, called the "trigger coil”. Magneto Ignition Building the magnetic field
." When the leading edge of the magnets in the flywheel approach the coil, the magnetic field surrounding those magnets generates a small voltage (about 1 volt) that powers a solid-state switching device called a Darlington Transistor, turning the transistor "on." That "on" mode completes the circuit on the primary winding and a current of about 3 amps flows to ground on the crankcase Collapsing the magnetic field
As the flywheel continues to rotate that current builds the magnetic field around the secondary winding.When the trailing edge of the magnets the flywheel reaches the trigger coil, a second small current is induced in the trigger coil and that current tells the transistor to "turn off", effectively breaking the circuit of the primary winding to ground (Figure 3), the sudden break causes the magnetic field to collapse. Since current (amperage) and voltage are inversely proportional, suddenly stopping the current flow causes the voltage to "spike" as it compensates. It's that spike that builds the voltage required in the secondary winding to jump the sparkplug gap and ignite the mixture. By the way, in the Magnetron coil, the primary winding has 74 turns of wire and the secondary has 4400. That's a 59.5:1 ratio and that helps insure that there's enough voltage to get the job done. All this, the initial current in the trigger coil, the buildup of potential, the second trigger coil pulse, and the collapsing field with the resulting voltage spike and spark, in on about 10 degrees of crank rotation. That means that at 6000 RPM the whole thing, start to finish, only takes about 0.00027 seconds. Pretty amazing.
This simple, but very effective, spark control system even advances the ignition timing, causing the plug to fire earlier (in degrees of crank rotation) as RPMs go up. Electronic Ignition Conversion Physics of Engine Performance
related to the Power Stroke Effects of Poor Timing
Most internal combustion engines are designed to ignite between 10 and 12 degrees BTDC to account for time between spark/injection and combustion.
Set too advanced and engine will knock and put added stress on Rod/Crank as it fights the up stroke of compression. Too little and the engine will have reduced compression at time of ignition which will substantially effect power.
Most engines have some type of mechanical timing advancement as well as initial as engine RPM’s increase. Boyle’s Laws
Boyle’s Law: the volume of gas varies inversely with the pressure. – Any confined gas will double its pressure when the volume is decreased by one half. Small gas engines use a compression ratio of 8:1. Theoretical compression pressure. Using an atmospheric pressure of 14.7 psi and a compression ratio of 8:1 the theoretical compression pressure is: Note: 117.6 The actual psi cylinder press will be different because of the losses that occur and the complex relationship between gas pressure and temperature. Charles Law
The pressure and temperature of a confined gas are directly proportional.
The increase in temperature can be approximated by:
0.4 T2 = T1 x n For an engine with a 8:1 compression ratio and an initial temperature of 72 oF, T1= initial temperature the compression temperature will be: T2 = final temperature 0.4 n = Compression ratio T2 = T1 x n o 0.4 An engine with a 21:1 = 72 F x 8 0.4 compression ratio and an T2 = T1 x n = o initial temperature of 72 165 F o 0.4 oF, the compression = 72 F x 21 temperature will be: = 243 oF Diesel Fuel ignites at around 500D F
Testimonial to Ether
When we first got our used tiller it worked fine for the first season, but when I went to get it going the next year it wouldn't seem to start, so I used a couple squirts of Starting Fluid spray and off it went. I only did this a few times, but that was enough to get our innocent Statesman tiller addicted to Ether, which is the main ingredient in this wicked spray. Now it won't start without this high end boost.
Don't get me wrong...in the hands of a qualified expert a short spray of Starting Fluid can be used to safely troubleshoot several specific problems.
The trouble happens when a back yard mechanic like myself was never told in Health class how repeated use of Starting Fluid begins to wear off the oil that usually coats the inner walls of each cylinder, which leads to accelerated wear on the rings, piston, and the cylinder itself. This creates a decrease in compression and explains the increased difficulty in starting. How To Read A Damaged Piston When a tree falls on a saw, there is rarely any doubt what happened, but when the engine fails, it is sometimes difficult for pro users to understand what has occurred and why. The following images of damaged pistons illustrate what can happen inside an engine. While the piston is not the engines only internal part, it is often the part that "pays the price" when an engine is not operated or maintained correctly. We hope this information helps explain what can occur and why, and more over, provide knowledge of how to avoid common causes of failure in the first place. Damage From Excessive Starting Fluid mirrors Running Unmixed Fuel
The piston below has severe scouring on the skirt with the heaviest damage upper portion of the piston. All of this damage was caused from running excessive ether. The lack of lubrication on the piston has caused it to seize to the cylinder wall. The damage you see was caused in the moments before the piston "stuck," which seized the engine.
NOTE: This kind of piston damage can also be found on an engine that was run with the carburetor set too lean or one that was run with an air leak. Force
“Anything that changes or tends to change the state of rest or motion of a body.”
A force can result in pressure, torque or work, depending on how it is applied.
The force acting on a piston/rod/crank resulting from ignition is substantial and the way that force acts is directly related to the INGITION TIMING. Force--Pressure
Pressure is a force acting on a unit of area.
Cylinder Pressure 800 700 600 The cylinder pressure is not constant. 500 400 –Increases during compression. 300
Pressure (psi) 200 –Sharp spike after combustion 100 0 –Decreases through power stroke 0 25 50 75 100 125 150 175 200 Time
How high can the pressure reach in a combustion chamber? Force—Pressure—cont.
In an engine the pressure produced in the combustion chamber is converted to a force. – The pressure is applied uniformly to all surfaces, including the head of the piston.
lb 2 Pressure 2 x Area (in )= Force (lb) in
Torque
“A force acting on the perpendicular radial distance from a point of rotation.”
To (lb-ft) = Force x Radius
Problem: Determine the amount of torque that will be produced for an engine that has an average combustion pressure of 250 psi, a 2.75 inch bore and 1.25 inch throw. lb 2 Force(lb) = Pressure x Area(in ) in2 lb π B2 = 250 x in2 4 lb 3.14 x 2.752 To = Force (lb) x Lever (ft) = 250 x 2 4 1 ft in = 1484 lb x 1.25 in x = 1484 lb 12 in = 154 lb - ft Typical Torque for a 3/4" Hardened Bolt is 160 lb - ft
Power
Power is the rate of doing work. P = W T Problem: How much power is an engine producing if the torque is F x D 154 lb-ft and the engine operates at P = 3,000 RPM. T P = To x RPM lb - ft 154 lb - ft rev P = x 3,000 min rev min lb - ft = 46,200 min
Horsepower
A unit of power developed by James Watt to provide a basis for comparing the amount of power produced by horses and other engines.
1 Hp = 33,000 ft-lb/min
1 Hp Problem: How many horsepower is Hp = Power x ft - lb an engine producing if the power is 33,000 46,200 ft-lb/min? min ft - lb 1 Hp = 46,200 x min ft - lb 33,000 min = 1.4 Hp
Fuels and Lubricants for Small Engines Jim Wills
Biosystems Engineering and Environmental Science Department Extension University of Tennessee
UT Extension Four-Stroke Operation
UT Extension Two Stroke Operation
UT Extension Failure to use proper oil*
* Viscosity (This is NOT thick or thin) * API Classification (SJ, SL, Etc.)
UT Extension Failure to change oil on a regular schedule
Mileage Hours of use Time of use (weeks, months, etc.)
UT Extension Failure to maintain proper oil level in crankcase
Check dip stick Check oil level plug
*Should be done daily
UT Extension Checking Oil Level
UT Extension Motor Oils
UT Extension Functions of Motor Oil
Lubricate moving parts Seal around gaskets, seals, piston rings Clean contaminates from engine parts Remove excess heat from engine
UT Extension Oil container has information on oil quality and viscosity
UT Extension API (American Petroleum Institute) circle contains API Service Classification and Viscosity
UT Extension API Circle
UT Extension VISCOSITY
What is viscosity? Viscosity is not Thick or Thin, Maple Syrup is thick but has 0 viscosity. Viscosity is the ability of the fluid to resist shear forces. Affected by temperature Affected by shear of oil molecules in lubrication process All oils are tested at same temperatures to establish viscosity rating
UT Extension Viscosity Values
SAE 0W, 5W, 10W, 15W, 20W SAE 30, 40, 50 SAE 10W-30, 5W-30, 15W-50, 10W-40, etc.
“W” means suitable for wintertime use (cold temperatures) “SAE”- Society of Automotive Engineers
UT Extension API Service Classifications
“S” - for gasoline engines (S- Spark ignition) “C” - for diesel engines (C- Compression ignition)
UT Extension Gasoline Classes
SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL SA is lowest quality SL is highest quality
UT Extension Diesel Classes
CA, CB, CC, CD, CE, CF, CG, CH CA is lowest quality CH is highest quality
UT Extension Petroleum Based Oils
Base stock of about 85% oil by volume Additives of about 15% by volume Additives include detergent, anti-oxidation, anti-corrosion, extreme heat, extreme pressure, anti-rust, etc.
UT Extension Value of Oil Additives?
Slick 50, T-Plus, STP, Motor Honey, etc. Usually not worth the price !!!
UT Extension Why Change Motor Oil?
Replace additives Remove contaminants ( water, acid, carbon, etc.
UT Extension When to Change Motor Oil?
At recommended mileage (3,000 on cars, trucks, campers, etc.) At 50 hours on small engines More often under severe conditions (pulling heavy loads, steep climbing, etc.) Change when oil is hot, not cold
Generally use Mfg. Recommendations
UT Extension Changing Brands of Oil
You do not have to use the same brand of oil forever in a given engine To change brands, drain old brand and replace with new brand – change oil filter at same time Use same viscosity
UT Extension Oil for Your Small Engines
SAE 30* SAE 10W-30 Synthetic oil * Above 40 degrees F
UT Extension Temperature Chart
UT Extension Synthetic Motor Oil
Better than petroleum based oil More expensive
UT Extension Advantages of Synthetic Oil
More detergent additive Better cold weather lubrication Better high temperature protection Longer engine life Better lubrication Better fuel efficiency Can be mixed with petroleum oil
UT Extension Disadvantages of Synthetic
Expensive (about $4.50/quart) Not recommended for turbochargers Not for dirty engines (inside of engine) Not for most diesels Not for new engines
UT Extension Tips for Synthetic Use
Use same viscosity Can be mixed with petroleum based oil Use regular oil filter Change at same change intervals
UT Extension Oils for Two-Cycle Engines
UT Extension Not the same as engine oils
Different additive package Different viscosity Higher price Different mix ratios Different rating system
UT Extension Mix with Gasoline for Engine Lubrication
Use only two-cycle oils Use proper ratio of gas to oil Use proper type of oil (TC or TSC-3) One mix and exact mix simplify mixing
UT Extension Mix Ratios
Parts of gas and oil to be mixed Can be ounces, pints, quarts, gallons Examples: 16:1 16 parts gas to 1 part oil 24:1 24 parts of gas to 1 part oil 50:1 50 parts of gas to 1 part oil
UT Extension Making one gallon mix
128 ounces in one gallon 16:1 mix 16 parts gas (128 oz.) to 1 part oil (8 oz.) 50:1 mix 50 parts gas (128 oz.) to 1 part oil (2.6 oz.)
UT Extension Two-Cycle Oil Classes
TA, TB, TC*, TD TSC-1, TSC-2, TSC-3*, TSC-4 ONE MIX* EXACT MIX* * For lawn and garden equipment
UT Extension Fuels for Engines
UT Extension Octane Ratings for Gasoline
Octane rating is a measure of resistance to pre-ignition of fuel
UT Extension Engine Ignition
UT Extension Octane Ratings
87 Octane – Regular 89 Octane – Regular+ 91+ Octane - Premium
UT Extension 87 Octane Fuel
Low resistance to pre-ignition – usually best for 4-cycle lawn and garden and automobile engines that are not high compression
UT Extension 89 Octane Fuel
Best for engines that knock or ping slightly on 87 octane fuel or older engines with slight carbon build-up in combustion chamber
UT Extension 91+ Octane Fuels
Best for high compression engines or engines that knock or ping on 89 octane fuels
UT Extension Leaded vs. Unleaded Gas
Lead was banned by EPA in 1989 because of air pollution Lead was put in gasoline to boost octane levels Some engines built before 1974 need lead to lubricate exhaust valves and seats Use a lead substitute in pre-1974 models
UT Extension Octane Boosters
Tetraethyl Lead* Ethanol Alcohol Methanol Alcohol Oxinol MTBE (Methyl Tertiary Butyl Ether)* * Now Banned from use
UT Extension Seasonal Blends of Gasoline
Winter Blend – Very Volatile Spring Blend – Moderately Volatile Summer Blend – Low Volatility Fall Blend – Moderate Volatility
UT Extension Gasohol
A mixture of 90% gasoline and 10% alcohol (usually ethanol) About 40% less air pollution from gasohol Can cause severe problems in some engines used infrequently
UT Extension Problems with Gasohol
Alcohol attracts water to fuel system Alcohol destroys plasticizers in gaskets, o-rings, seals, floats, diaphragms, etc. Alcohol causes severe corrosion Alcohol dissolves some additives in two-cycle oils
UT Extension Gasohol vs. Gasoline
Gasohol – 78,000 BTU’s per gallon Gasoline – 115,000 BTU’s per gallon
UT Extension Gasohol and Small Engines
Avoid use of gasohol fuels in small engines- especially two-cycle engines
UT Extension Fuel Useful Life*
Gasoline – about 90 days Gasoline + Two-cycle oil – About 60 days Diesel Fuel – About two years * Depends greatly on temperature and humidity
UT Extension Fuel Stabilizers
Can be added to fuel in storage container Can be added to fuel storage tanks Can be added to fuel tank on engine Can be added to fuel tank for long term storage of equipment* * Run engine for five minutes to distribute stabilizer to all parts of fuel system
UT Extension Fuel Life with Stabilizers
Gasoline – Up to two years Gasoline + Oil – Up to one year Diesel Fuel – Over two years
UT Extension Stabilizer Brands*
STA-BIL GUMOUT McCullogh Others *Available at Wal-Mart, K-Mart, Auto parts stores, etc. *Costs about 10 cents/gallon of fuel
UT Extension Disposal of Used Oil
Contains carcinogens !!! Do not pour on ground !!! Collect oil in suitable container Take to recycling center for disposal Centers will also take gear oil, transmission fluid, antifreeze, freon,
UT Extension Used Oil
One gallon will foul taste of one million gallons of fresh water Toxic to plants and animals Can be refined into new oil* *One gallon of used oil will make 2.5 quarts of new oil
UT Extension Off Season Storage of Small Engines
Change engine oil Drain fuel tank* Clean exterior of engine Remove spark plug, add one table spoon oil, replace spark plug Cover loosely to keep clean Store in dry location * Add fuel stabilizer to fuel tank
UT Extension Adding Oil At Sparkplug
UT Extension Cleaning Engine Exterior
UT Extension The Beginning of a Better Maintenance Program and Longer Life for Engines on Your Maintenance Equipment
UT Extension