Mower Starting Tips

The Handyguys discuss annual spring maintenance and home improvement for your lawn mower

For many of us in the northern parts of the USA, it is that time of year when we get the lawn mower out for the first time. Most of us probably use tradition walk behind mowers with combustion engines. Like our cars, these tools require maintenance to keep them humming along from year to year. The Handyguys discuss how you can handle these basic maintenance items yourself:

We start off by talking about mower safety and some crazy mower stories before we get into the basics of spring mower tune-up.

Basic spring mower tune-up consists of checking and maybe replacing the spark plug, cleaning or replacing the air filter, sharpening your blade, cleaning the deck and changing the oil.

This is an example of a bad sparkplugChanging the spark plug: The spark plug only needs to be changed if its black, burnt, or damaged. If it looks clean when you remove it, only replace it if you are having trouble with the mower running smooth or not starting. This picture is an example of a badly fouled plug that needs replaced.

This filter could likely be cleaned with compressed air or a brush. I chose to just replace it.Replacing an air filter: Make sure you get the correct air filter. There are many sizes and styles. The filter can be cleaned with compressed air or a brush. If its really bad, just go ahead and replace it. Some filters are foam and can be washed in warm soapy water. Do not re-install a washed filter until its completely dry.

Sharpen your mower bladeSharpening a blade: You can use a file or a grinder to sharpen your blade. Make sure you use the same angle as the previous sharpening. Handyguy Brian got this heavy duty grinder for only $25, including the stand, at an auction. An inexpensive grinder will be fine for this task. A Dremel tool or even just a plain old file will do the trick as well. A sharp blade makes a better cut and helps keep your grass healthy. Tip – If your blade bolt is stuck, try soaking it in some Liquid Wrench!

Clean the grass and removing the mower bladeCleaning the mower deck:  Use a scraper and a wire brush to clean up the mower deck. This is especially important for mulching mowers. If you have rust, sand that and hit it with some primer and paint.

Changing the oil: Do this every year. Make sure you use the proper oil and the correct amount. Most mowers will use SAE 30 oil. Do not use 10W-30, its different and will likely void any warranty you may have.  Check your owners manual first for the correct oil.

Learn more by listening to this installment of the Handyguys Podcast!

13 thoughts on “Mower Starting Tips

  1. We received this related question via the contact form an thought we would post it here…
    “Inspired by your latest podcast, can you give me some pointers on sharpening the blades of my reel mower on my own, or is this something I will definitely lose a finger doing? This is something I’ve been meaning to do, but haven’t even had the time to think about how yet.

    ~Kit S.

    Kit – Sharpening a reel mower will depend on its vintage. reel mowers cut like scissors do. An antique reel mower will need to be sharpened like any other blade. They are hard to do though because an equal amount of grinding needs to be done across the entire length of the blade and then the mower needs to be properly adjusted to mate up the fixed part of the ‘scissors’. A more modern reel mower is best sharpened with a kit from the manufacturer. American Mower makes most of the modern reel mowers. Here is one example of a kit.
    The way this works is by cranking the reels backwards after applying a grinding paste. This action sharpens the blades.

    If your reel mower does not have a kit or a simple way to do it I would recommend finding a sharpening service to do it for you.

  2. I am really enjoying these podcasts, some really great tips. Just recently found this site and will eventually get caught up to your recent podcasts. One thing I would like to add to this podcast however is when you are working under the mower near the blade to remove clumped grass or to sharpen the blade (I use an angle grinder), disconnect the spark plug wire from the spark plug. You can actually start the mower by moving the blade out of the way. I am not missing any digits, but I know a few who have had close calls.

    One question that I have is with the carb. I am working on a mower and did the standard tune-ups, plug, oil and air filter. I have a situation where the mower is idling really rough almost to the point of cutting itself off. Since my first go round with the tune up did not fix the problem, I am planning on removing the carb to attempt to clean it. Do you guys have any suggestions on cleaning the carb before I go out and buy a new one? I’ve replaced carbs on mowers before just never cleaned one. Thanks and keep up the good work

    1. Hey David – Thanks for your comments and question. You can buy carb cleaner spray at an auto parts store or maybe even the home center. Its a cheap thing to try. Also, your engine manufacturer likely has carb rebuild kits that are cheaper than entire new carbs. You may want to also inspect the fuel line for kinks and replace the fuel filter if it has one. The fuel filter is a lot cheaper than a new carb if thats the issue. Also, I only use fresh premium gas in my mower and run it dry when its going to sit for a long time. Good luck and let us know how you make out!

      1. Thanks for the response. Sorry for the delayed followup. This project fell on the honey do list for a little bit. I tried spraying carb cleaner through the carb as it was running but saw no improvement. The owner hadn’t listened to your podcast on proper maintenance of a mower so it was very dirty. There was dirt and old grass around the throttle springs which could also have been preventing it from idling at proper speed. Because the air filter was so dirty, there was some dirt in the carb. I cleaned it with the carb cleaner and used my air compressor to blow out the lines. It feels like a waste to spend 30 bucks on a rebuild kit. I just went to harbor freight and got gasket material and a o-ring set for much less than the rebuilt kit. Now I have enough o-rings and gaskets to do several carb jobs. The mower works much better now. I do still need to fiddle with the idle springs to get it to the right speed. Thanks again for your help. Love the podcasts, keep them coming.

  3. I have a MTD, 21″, 6.5 hp lawn mover, 10yrs old, regular tune up and working fine until now. Now the service man says that the engine is rotating at 36000 rpm (measured with a tachometer placed on top of engine) and is dangerous to use because it is higher than the recommended speed. He recommends to fix the engine controller for $150 or trash the lawn mover.

    Need your advice

  4. I need help troubleshooting my over 10 year old Briggs/Stratton push mower. It will start but stops within a few seconds. I have used carb cleaner and fuel treament and started and ran for about 30 minutes then started to stall but when I tilt the front up I noticed that it would not stall. Any suggestions. Thanks. Pls shoot me an e-mail at this e-address. [email protected]

    1. My guess is that the recently used gas contains ethanol. Its unavoidable but does very bad things to small engines. It can dissolve the fuel lines, varnish the carb and generally ruine the engine.

      Try this.
      Drain the gas (You can use it in a car).
      Check the fuel lines, if they are soft or cracked replace them.
      Put FRESH premium gas in, not from the can, but fresh from a busy gas station.
      Add a product called Sea Foam to the gas, follow the directions for how much to add.
      You will want to run a few tanks of fresh, premium, gas with SeaFoam through the engine.

      This may clean things out. If not, your small engine repair guys will be quite familiar with the issue and should be able to help.

      Good luck

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