Recently I picked up a used riding mower and I am making a list of things to do so I thought it would be a good time to talk about what you should do if you purchase a used lawn mower.
Lawnmower servicing is really a great introduction to engine care for your car. If you are or have a teenager you should get them involved in the care of your lawn equipment because it will be a great education for taking care of their vehicle when they get older. Many of the things you need to do are similar and lawn equipment is more forgiving and less complicated than a passenger car.
When you are looking for a used lawnmower whether its a push mower or a riding mower you want to understand the features and cost so you can make a good deal on the sale.
One thing I have noticed is that many sellers expect to get more for their equipment than it is worth but this could be because they are building in a negotiating buffer. If you know your mower is worth $100 and that is what you are willing to sell it for you almost have to list it for $125 so the potential buyer can offer less and you can accept it. If you start off at exactly what you want unless its on a buy it now auction you have less negotiating power. This really means as a buyer you need to know the real worth of a used piece of equipment so you understand what you should offer for a reasonable deal.
When making the purchase you should make sure that the equipment works and that all of the options function. If the mower has power assist you should make sure it engages and is strong. If your riding mower has manual shift you should make sure it shifts into different gears and runs well. You shouldn’t cut the sellers lawn but you should make sure the basic things function and it is in reasonable condition for its age.
What to do before you use your used Lawnmower
When you get your equipment home you shouldn’t put it into use right away. If you need to run it for a short time to drive it to your shed or garage or maybe to clean it up that is fine but you don’t want to jump right in and use it as if it was new. Even new equipment requires preparation before use so you should expect used equipment to need the same or more prep time.
The first thing you want to do is give the equipment a good cleaning. The seller should have cleaned up the equipment just because they are trying to get the best price for it and something dirty won’t sell even if its new but because you will need to perform inspection and servicing you really need to make sure its as clean as new.
I don’t suggest that you use a pressure washer on your lawn equipment but it would be ok to use on the underside of the mowing deck and maybe on the bagger. Never use it on or near any parts of the electrical system or engine. Even a normal hose should be used modestly when cleaning around an engine because you don’t want water to get into things like your starter or carburetor. Once the equipment is clean you can get to servicing it.
Servicing your Fuel System
Before you change your oil you will want to drain and service your fuel system. You may need to do additional work later but you don’t want to run the engine on dirty or old gasoline.
If you can remove the gas tank you should do so and drain the tank then wash it clean with a small amount of gasoline. If you can’t remove it you should at least unplug the fuel line and flush the tank clean.
Replace your fuel filter if you have one. Most riding mowers will have a fuel filter and you can get them pretty cheap.
While you are replacing the fuel filter you may want to replace the fuel line and the fuel cutoff valve. Most fuel line is 1/4″ inside diameter and you must specify and use FUEL LINE not vacuum or water line.
If your mower came with a fuel cutoff valve that is inline with the fuel filter you might as well replace it. If it did not come with one you should install a fuel cutoff line on all riding mowers. Fuel cutoff valves restrict fuel from entering your carburetor when not in use. It is an important fire safety precaution and it will also mean your carburetor could last longer.
Rebuilding or cleaning your carburetor is a later step if your mower is running well there is no reason to consider this right away. However if it is not running well you should look into a carburetor rebuild kit for about $15.
Replacing your air filter is important and you should understand the type of filter you have and use the correct type. Often push mowers will have paper filters but some come with foam filters that can be washed. Foam filters often require washing often and then they are treated with oil to help catch dirt. Riding mowers with larger engines might have a foam outer filter that protects a paper inner filter. You should clean and reoil the foam filter and replace the paper filter. It is a worthy investment so do it even if it looks rather new.
Change the oil before you use your lawnmower
If you purchase a used lawnmower it is extremely important that you change the oil before you use it. The previous owner may have kept it in perfect order but every engine will have metal fragments in its oil and crankcase area that you need to remove. Even a brand new engine normally requires that you use it only for a short period then change the oil to remove the assembly debris. A used engine will definitely have buildup of sludge and metal fragments you need to remove. Additionally you have no idea what type of oil the previous owner used. They might have used the cheapest discount store oil just to change it so it looked good and you should invest $5 in a quart of good oil to get it running well.
Read your service manual and you can normally find them for download from the manufacturer’s or the retailer’s website. They will suggest the grade of oil for your lawnmower. Normally small engines should use 30W oil and not a blended mix such as 10w40. However if the riding mower or maybe a Snow Thrower is being used in temperatures below freezing for removing snow a mixed blend may be suggested. If you do use a mixed blend understand your engine will burn oil much faster than normal single weight.
I suggest that you flush your engine with a quart of cheap oil and then refill it with a quart of good quality oil. Flushing the system means that you use the same grade oil as normal but it does not have to be an expensive brand.
Run the engine until it reaches operating temperature and then remove the oil that you bought it with. Make sure to take your time and allow the oil to fully drain.
Refill the engine with cheap oil you will use for flushing and start the engine again and let it get to operating temperature. Now drain the oil again and replace it with a good quality oil of the correct weight and grade.
The first oil you removed should be discarded but the second flush oil can be saved if it looks reasonably clean for general lubricating oil around your home.
If the flushed oil is very dark or you notice metal fragments in it you should flush the engine a second time. Large fragments of metal means internal damage to your engine has already occurred and it will probably mean rebuilding or professional servicing is required. However it is not uncommon to see chunks of dark sludge or even a small amount of glittery metal smaller than a dot on the letter “i” . If you see that in the initial or flush oil .. reflush until it is clean.
Inspecting and Changing your Spark Plug
Again here it is really one of those things where even if your plug is relatively new and in good condition you should probably invest in a new one just to start things off right. If you end up having a spark problem you want to eliminate this as the cause so pick up a spark plug when you get your oil and filter.
Even though you are replacing it you want to inspect the plug for information about how your engine is running.
A good spark plug will have an inter ceramic cone that looks light gray like cigarette ash. It should not be wet or have oil on it. It should not have cracks in the ceramic cone and the L shaped electrode should not look like it was eaten up by acid it should look like an L but may show some wear as will the electrode tip in the center of the cone if the plug is older.
Spark plugs are marked so you can replace them but also check your manual you never know if the previous owner swapped in a random plug just to get it running. Most small engine plugs will have a R in their name meaning resistor.
Check and Sharpen your Blade
Before you start cutting your grass you want to sharpen your blade if it is in good condition or replace it if it looks worn or bent.
BEFORE YOU DO REMOVE THE PLUG WIRE FROM THE SPARK PLUG.
Never work on your blade with the spark plug wire connected.. NEVER!
If you have electric start then remove the battery cables too.
Blades are a little more expensive than some of the other parts we have talked about so far and having a good operating one is fine as long as it does not look like it has ever been damaged from hitting a rock or other object. if there is any hint that it is bent you should replace it.
When you sharpen a blade you need to sharpen both sides of the blade and make sure that it is balanced. An unbalanced blade can hurt your engine over time causing stress on bearings. When in doubt bring your blade to a lawn care store or replace it.
Final Note
This is a short list of a few things you really should do before you use any equipment that you purchase used.
It is really worth your investment to find a copy of the user or service manual and replace or service any item that normally needs servicing. Whether its a item you are suppose to check every time you use it or something you do once a year. You should go through all of those service items and replace everything that normally needs replacing.
This way you may not have a brand new product but at least you know the care of the equipment is up to date.