Riding Lawn Mower Won't Start -- What to Try Next?

[Alan Whitehouse]

Hi,

I have a MTD (Yard Man) Riding Lawn Mower.

It won't start.

Last year I put it to bed for the winter and started it twice during that time. The last time I backfired loudly as I turned it off but thought nothing else of it.

I left it on the battery charger all winter doing a trickle charge.

It won't start.

The engine cranks and cranks but I can't get it to start.

I have checked the battery it is good.

I have a spark from the spark plug.

The fuel is flowing and I had stabalizer in it over the winter.

It just won't turn over. I have also tried starter fluid in the carburator.

Other suggestions?

If not, anyone know anyone in the Markham/Stouffville (outside of Toronto, Ontario) who does small engine repair on-site? I don't have the means to take the tractor anywhere right now.

Thanks.

Alan

[reader]

You backfired loudly?

[Pat]

Check the compression.

[Alan Whitehouse]

How does a novice check the compression? Engines are not really my thing.

[Pat]

Pull the spark plug and use a compression gauge like this one

[Artemis]

That is probably a waste of time and I doubt you own a compression gauge.

You don't say what engine you have so I will have to guess an 8-12 HP Briggs. Backfires are caused by shutting the engine off when it is running at full throttle. The carb continues to supply fuel/air mix to the engine but the spark plug is no longer sparking. All that fuel goes into the hot muffler where it gets ignited - BOOM. Always throttle the engine down before turning it off and it won't do that.

If it has not run this year then drain the carb, watch for water in the gas, and refill with fresh fuel (fresh from the gas station, not from your can from last year.) I'd also put a new spark plug in it.

Most shops will pickup, repair and then deliver the unit back to you. On-site service is quite expensive and iffy at best. To carry around the number of parts needed to adequately service everything out there is prohibitive. This usually results in parts (head gaskets are number one) being reused when they should not be.

[Steveo]

ohhhh...you should have told him to hold on to it and check for spark! :)

[Srgnt Billko]

A novice might do a simple rough check by taking the plug out and placing your thumb tight over the plug hole. You should be able to fell it suck in on intake and push out on exhaust. Note - make sure the plug wire is out-of-the-way and not touching you.

[Srgnt Billko]

But is it getting in to the cylinder ? Is the plug wet when you take it out ? If the plug is dry try sealing your lips inside the gas tank opening and blowing as long and as hard as you can.

[Stubby]

My GUESS is you have a burned valve. A compression will be low. The shop can remove the head, grind the valve seat(s), replace the valve, oil seals and springs and the head gasket. With the right equipment, it's only a half hour for them, but it is beyond the scope of a home repair.

[Artemis]

Just curious here, what makes you think he has a burnt valve?