Ride on mower starting issues

[Marty_d]

Hey, 

Hoping the brains trust can help me out here.

We inherited an MTD Yard Machines 14hp ride on from my father in law about 10 years ago.

Up to now it's been really reliable, even though I only use it about 4 times a year it starts first time.

Anyway, I was using it a couple of weeks ago and the drive part stopped. Without thinking, I tipped it on its side to work out why, discovered a broken spring, and went to the shed to see if I had a replacement the right size.

You can probably guess. Yes I got distracted by something else, then it was time to make dinner etc, and before I knew it three days had passed before I remembered the mower on its side in the paddock.

The oil flooding the air filter didn't do it much good.  I cleaned out as much oil as I can get to, got a new air filter, topped up the oil, put fuel in and charged the battery.

Now, even with "Start ya bastard", it doesn't start.

Any ideas about what else I could try, before giving up and selling a kidney to get it fixed?

Thanks!

[pmccarthy]

I would leave it stand for a week or two to let oil drain back out of wherever it went. Clean the plug. Pull off the float bowl and clean it.

[Litespeed]

,,,Have you fully cleaned the plug and combustion chamber by running the starter without the plug in?

 

Have you cleaned the carburettor? Use brakeclean as it does not effect plastic or rubber seals.

 

New clean fuel?

 

Try these first.

 

Good luck

[Jerry_Atrick]

Hi @Marty_d,

 

I have no idea, but I put your post into Chat GPT  and here's it's repsonse

Ouch — yeah, tipping a small engine and leaving it there is one of those “ask me how I know” moments. The good news is: this is very often recoverable without selling organs.

Here’s a logical, low-cost checklist, in the order I’d attack it.

---

1. Spark plug: almost certainly the main culprit

When oil floods the intake, it usually ends up:

• coating the spark plug

• sometimes filling the cylinder

Do this first:

1. Remove the spark plug

2. If it’s oily → either:

   • clean it thoroughly with brake cleaner / carb cleaner and dry it, or

   • replace it (they’re cheap and worth it)

3. With the plug still out, crank the engine a few seconds

   • This blows excess oil out of the cylinder

   • Put a rag over the hole unless you like oil facials

👉 If you skipped this step and tried to start it, it may still be oil-fouled even with a new air filter.

---

2. Check for spark (quick sanity check)

With the plug out:

• reconnect the plug lead

• hold the metal body of the plug against the engine block

• crank the engine

You should see a strong blue spark.

• ✅ Spark present → move on

• ❌ No spark → kill switch / safety switch / ignition coil issue (see section 5)

---

3. Carburetor is likely flooded with oil

Oil can:

• sit in the carb bowl

• gum up the main jet

• block air passages

Easy attempt first:

• Turn fuel tap off (if fitted)

• Drain the carb bowl (usually a small bolt underneath)

• Turn fuel back on

• Try starting again

If still no joy:

• Pull the carb off

• Clean with carb cleaner (especially the main jet)

• No rebuild kit needed unless seals are shot

---

4. Check oil level (very important)

After tipping, oil can end up:

• in the intake

• in the muffler

• missing from the sump

Make sure:

• Oil level is correct (not overfilled)

• Overfilling can also prevent starting

---

5. Safety switches love to cause false alarms

MTD ride-ons have multiple interlocks:

• seat switch

• brake/clutch switch

• PTO/blade switch

When tipped:

• connectors can pull loose

• switches can get oil contamination

Check:

• PTO disengaged

• Brake/clutch fully depressed

• Seat switch connector intact

(Temporarily bypassing a switch for testing is OK, just don’t mow like that.)

---

6. Exhaust full of oil? (Often overlooked)

If oil ran into the muffler:

• engine may struggle to breathe

• may not start or will smoke like mad

Fix:

• Remove muffler

• Drain oil

• Refit and expect smoke for a while

---

7. Compression check (quick and dirty)

With spark plug back in:

• Turn engine by hand or crank it

• It should feel like it’s fighting you

No resistance = valve stuck open (rare, but tipping can cause it)

---

Most common outcome

In 90% of cases like yours, the fix is:

• new spark plug

• clearing oil from cylinder

• draining carb bowl

• fresh fuel

They are remarkably forgiving engines.

---

Before you give up:

If you want, tell me:

• exact engine brand (Briggs & Stratton? Tecumseh?)

• model number (on engine shroud)

• whether it cranks strongly or slowly

I can walk you through model-specific steps and avoid unnecessary repairs.

[onetrack]

Make sure the oil hasn't spread onto the flywheel and coil. Take the engine cowling off and clean the outside surface of the flywheel and magnet and the section of the coil that sits close to the flywheel. Use some emery cloth to clean up the flywheel outer surface and check the coil to flywheel gap. Install a new spark plug (90% of starting problems). Use some "Carburettor & Throttle Body Cleaner" (spray can) to clean out the carburettor passageways. 

 

No sorry, all that above is made-up BS. What actually happened is, you killed the little hamster inside the engine that makes it go, when you tipped it over and left it.  You need a new engine hamster.

 

Edited 17 hours ago by onetrack

[Marty_d]

Ah, 14hp means 14 Hamster Power? Thanks gents!

[nomadpete]

If you had told me yesterday Ida come over and sorted it forya.

[facthunter]

What BRAND of motor is it?    IF you crank the Motor with the Plug out , earth the lead.  Nev

[Marty_d]

Tecumseh I think. At least that was on the air filter I replaced.

[facthunter]

Cast Iron Motor.  about 40 years old. Clean  air filter drain and clean carb bowl and check oil in combustion chamber which may foul the Plug. Put Piston near  TDC and try blowing it out with compressed air.  Nev