Most reason Your riding mower or push mower not starting

Posted by
Spread the love

Most reason Your riding mower or push mower not starting

Your lawnmower will not start,

Check the battery cables if the engine will not start. Tighten the connections if they are loose. A loose battery connection will prevent power from getting to the mower

 the first thing check is gas turned on and is there gas in the gas tank. If fuel has been sitting in your tank couple years change it.

If the gas tank is not the problem, a possibility the mower battery is damaged, will the motor spin or turn over if it does this proves batter is fine. .  Also check if mower is in neutral, the blades are not engaged, and clutch is mashed in and seat is mashed down.

If turning key motor will not engage could be the battery or  Bad Starter Solenoid

If mower still won’t start? I would try adding a little gas to the carburetor and see if engine will start. If it starts you might just have a dirty carburetor.

If mower still will not start next I would pull plug wire and make sure engine is getting spark.. If no spark next I would set my ohm meter on 20 ohms and touch one end to inside plug wire and other to coil frame. You should get 2.4 or a reading close. This mean coil is good, If no reading coil had gone out.

If coil is fine my next check is to take off the tiny black wire which is plugged into coil.  Then try starting the engine. If engine runs fine. You have found problem, One of your mowers sensors is keeping motor from starting. Note: you can not kill  mower now. the tiny black wire is the kill switch. touch that wire to any part of engine and motor will die. What you did by removing the wire  is bypass all sensors. Now your problem could be seat sensor or a few more depending on type of mower.

Most common problems below.

  • Gas Valve Off
  • No Gas
  • Choke Fault
  • Plug Wet / Faulty
  • Plug Wire Off
  • Bad Battery
  • Air filter Blocked
  • Gummed / Faulty Carburetor
  • Coil Failure
  • Faulty Control Module
  • Flywheel Timing Off (Shear-key)
  • Engine Compression / Valve Fault


If the filter looks good, the height of grass you are cutting could be bogging down your mower. If grass is tall, then adjust the cutting height.

Make sure your blades are sharp and not clogged up with twine or wire you picked up mowing.

If you mower is still losing power you can try replacing the plug which may of gone bad. Another  problem if you run your mower for a while then start loosing power I would be thinking the coil on your mower is going bad.

Another thing that will make you think you mower is not doing its job is a bad or week drive belt or cutting belt. I have seen many of them go bad, I love the Kevlar strong made belts.


 Lawnmower is smoking

Common problems when mowing the grass. Manny people believe a smoking mower is a sign that the engine is about to blow up.  Smoking of the engine in many mowers are, caused by overfilling of the oil chamber. Check your dipstick and make sure the oil is within the mowers dots on the dipstick.. Is the oil leaking and smoking on exhaust? This leak could be coming from value cover or you may have a engine crank case value going bad and letting oil get into carburetor. If you mow with your mower where slopes and hills are and mower goes  towards a particular side when moving , there is a likelihood of oil leaking onto the muffler, causing the engine to smoke. In such a case, examine the oil chamber for leaks. If no leaks,  a possibility  the oil  cap is loose. Tighten the cap and start the mower. If the problem persists, and no oil is leaking on engine. I would be thinking maybe a bad oil ring on the piston or the rings close gap is aligned letting oil through.

The engine rattles and hums.

Problem could be the belt that spins the blades is to loose or almost worn out. Or you might have a blade spin pulley going out. Easy to check just spin each pulley if easy to spin no problem but loose or grinding noise the bearing is going out and will need replaced.

Unusual and Excessive Vibration

bent or damaged  blades. A lawnmower goes over hard objects such as roots, rocks you can damage parts of the mower. A bent or warped blade will cause you bad vibration.

A faulty drive belt might  cause the lawnmower to produce unusual and excessive vibration.

Many other factors can result in vibrations such as loose mounting bolts, running the engine below the recommended RPM, failure to adjust the cutting deck appropriately.

 Mower will not cut the grass.

A couple things I would check, is your blades sharp, is your blades spinning good, it may just be you have a bad loose cutting belt. your blade belt.

Mower cuts Grass Unevenly

Mower cuts grass uneven, uneven cutting is usually caused by mower deck damage or out of alignment. To fix. I would check

tire pressure. Under-inflating or over-inflating the tires can bring up plenty of wrongs including weird steering, mower wobbling, and making the deck to sit unevenly.

If its the deck making you mow uneven.

Measure the heights of both the mower’s front and the rear blade tips to the ground.

Front and rear and raise/lower the deck to the sweet spot. A lot of time this adjustment will fix alignment problems.

The two measurements should be the same. If the measurements are a 1/4″ or more off, it needs to be corrected. The next thing to do is to turn the blades and measure again. If the measurements are not the same, one of the blades is probably bent. Other things to check for are damage to the deck shell, and bent or loose spindles.


Most reason You push  mower not starting

Out of Gas, and I have had many mowers that would not start till I put a little gas in carburetor.  Also I have had a few

that you must use the self primmer and prime about 10 times and mower starts.

Next I would check for sparkplug fire, Is the engine firing to plug, If fire great If no fire, could be bad coil or the engine shut off wire could be touching the frame.

To check coil you will need a ohm meter, just put one end inside plug wire and touch the coil frame with other end or ohm wire. You should get a 2.4 reading or close If you do great

all if working if no reading your coil is bad. 

Also on push mowers I have hit hard thing like a small tree stump and killed my mower and it would not start again. I had to replace the timing key or some people

call it flywheel key.  This key is made to protect your engine, When it breaks all you need is to add a new key.

I would like to add another simple reason my mower(Lawnboy) would not start…
I don’t use the rear bag so I have a plug to block the grass exit hole. This plug has a metal lever to lock it in place. Well, there is an interlock switch for this lever. If it’s not fully inserted, the mower won’t start. It’s only once I had pretty much completely disassembled the whole mower and noticed a wire going to the back near the exit hole that I realized this…

On both push and riders, some have a low oil shut off switch. Make sure to check your oil EVERY TIME you put in gas and before use!!!

Now my push mower starts fine after cutting the front yard and go to back yard shutting mower down now mower won’t hit or try to start.

 Like it has to cool down, This problem is caused by bad coil. The coil is heating up. replace coil to fix.

You push mower vibrates bad, You have a bent blade or the bolts have come loose holding you engine to the frame.

Leave a Reply

Please Login to Comment.