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 December 17 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

[Litespeed]

Did you get the mower going?

[nomadpete]

No need to if he borrowed the neighbour's goats.

[Marty_d]

31 minutes ago, Litespeed said:

Did you get the mower going?

Not yet. I was distracted by other things last weekend.

[Litespeed]

Goats are excellent mowers and tasty when the jobs done.

[onetrack]

He hasn't been to the engine hamster shop yet.

[facthunter]

Goats Pine for their owners, and can be very upset. when left alone.  They are good at eating blackberry bushes. I suppose My Dexta Tractor is able to mow when the slasher is attached to it,  That's one of the reasons I
bought it second hand in  1973. I've had the exhaust Manifold soaking in degreaser for about a week to remove the Internal carbon deposits. Not far off firing it up. It holds only 5 litres of coolant.  Like all such jobs you spend about 5 times what you expected to on it and it's been very hot in the Place where I'm working on it.   Kitchen Stove just being replaced at the Moment, right on the deadline for Xmas EVE. I had great difficulty getting it.  My pet Blue Tongue has deserted Me. My beautiful Howard Rotary Hoe has a new Owner. It's practically Never had a spanner on it. Never Monstered or left out in the weather.  Happy Xmas everyone. I might Make 86 in 10 days. The trouble with that is the majority of my contacts/ Friend s and relatives have Passed on. . Cheers. Nev

[rgmwa]

2 hours ago, facthunter said:

Happy Xmas everyone. I might Make 86 in 10 days. The trouble with that is the majority of my contacts/ Friend s and relatives have Passed on. . Cheers. Nev

Same to you Nev, and I hope you last a fair bit longer than the next 10 days. I'm a bit younger than you, but I'd say everyone here has lost friends and relatives along the way. That's life, unfortunately, but much better to still be here among the living than listed with the missing.

[Litespeed]

Nev, 

 

Your going to be 68, celebrate that and enjoy dyslexia.