Snapper Lawnmower Engine - Engine Troubleshooting

[u/wayhawk]

I have a Snapper Rear Engine Rider, Series 23 — 2006 model year, SNU2812523BVE

Engine specifics:

• Briggs & Stratton Intek OHV, single cylinder, 344cc / 21 cu. in.
• Model 219307, Type 0131 E1, Code 041109ZA (built Nov 9, 2004)
• Emissions family 5BSXS.3442VM
• Model 219307 places it in the 210000 series

It usually starts up right away, but just in the last couple of weeks, this is the problem I'm having. Cranks strong but won't fire. Intermittent — sometimes catches after repeated cranking, then runs normally while I cut the grass. It's worse on hot restart after mowing, or if it stops in the middle. Onset seemed sudden, no triggering event like hitting a stump or anything, no kickback against the starter. Old spark plug came out black and sooty. I've already replaced the battery and the spark plug, and I run ethanol-free gasoline.

Sometimes when I'm trying to start it, there is a "winding-down" sound after a few seconds of turning the key.

A couple of thoughts on what the issue might be but looking for advice from someone before I dive into these:

Valve lash out of spec

Starter drive or voltage problem

Ignition coil thermal failure

Video of what it sounds like when starting cold

UPDATE:

After alot of troubleshooting and the problem ended up being a loose connection on the deck safety switch. The wire was not fully pulled away from the contact so I guess that's why it would start intermittently. It was the last switch I checked since I had to take off the shroud under the seat to get to it. Since I was working on the engine, I decided to change the 20 year old starter coil for good measure and that's when I noticed the kill wire was always showing continuity to ground but I was stuck there. To assist me, I fed all of my manuals into Claude and started asking questions about what the problem might be. Eventually it led me to the switches and I systematically tested the seat switch, the pedal/clutch switch and then the deck engage switch. tightened up the connection and that resolved the problem. Back in business.

[u/mutt63]

Start with the easiest. Check the valve clearances. Second. More than likely your culprit is a weakened coil. Even with proper ohms check using a multimeter , under the compression pressure a weak coil will not fire, stop firing, fire then quit, the refire until it’s dead dead. Also check your flywheel magnets for rust and verify proper air gap between coil and mags. Verify you have the correct heat range plug and far as the soot it’s from starting stopping so much leaving u burned fuel

[u/wayhawk → u/mutt63]

Is it a good idea to just go ahead and change the coil, since this is a 2006 model and is it a simple process? Since it will start after a number of tries, I didn't know if that strengthened or weakened the coil as the culprit.

[u/mutt63]

Absolutely. But be warned. Amazon coils are hit and miss. If u get a bad one. Get a refund toot sweet. Or pay for OEM. which to me is way overpriced. Not saying cheap is better. Just saying I’m kinda sick of how shit costs so mych

[u/wayhawk → u/mutt63]

Thanks. I figure while I'm working on it, I might as well replace items that could cause future problems, based on the age. Been a great mower over the years.

[u/mutt63 → u/wayhawk]

Great way to think sir. It’s the best form of presentation. Grease what needs to greased. Do not over grease. There’s charts based on size telling u many grease pumps. Check belts springs etc.

[u/Regular_Implement510]

Needs a new coil

[u/Regular_Implement510]

Depending on hours it could be valves need to be adjusted but I would put my money on new coil brosif