Small Engines (Lawn Mowers, etc.): briggs & stratton intek 17.5 hp motor

Question
My 17.5 intek motor will crank but not start. It is getting fuel and good spark, and tried starting fluid and still won't start, and I checked the compression and is showing low compression. I took off flywheel to check for sheared pin, but was good. What would you suggest it might be or what direction should i look at going forward.

Thanks

Gary

Answer
Spark plugs.  If you know you have fuel and spark then it should start.  Briggs rarely publishes compression specs due to variations across engines.

Per the Briggs manual,
Testing Engine Compression

When your engine has leaks around the valves or rings, compression of the air-fuel mixture suffers. When this happens, performance and efficiency can drop dramatically. A spin of the flywheel will tell you whether the compression in your engine is sufficient.

1.  Disconnect the spark plug lead and secure it away from the spark plug. Remove the blower housing. Then, disconnect the brake pad or band, if equipped (see "Servicing the Brake").

2. Spin the flywheel counter-clockwise by hand (image A). If compression is adequate, the flywheel should rebound sharply. Weak or nonexistent rebound indicates poor compression (see "Troubleshooting" for a list of possible causes and remedies).

It does not take much compression for the engine to run.  Better (higher) compression usually equals more power and an effecient engine.

If you know for sure you have spark and it will not start on starting fluid I'd suspect compression or timing.  You verified timing via the flywheel key.  This leave compression to be the problem.  However, low compression, to the point a Briggs will not start at all is rare unless a valve is stuck, head gasket blown, or a broken rod.  Most of these symptoms are pretty obvious and easy to troubleshoot with a compression gauge...if you have 50-90 PSI the parts (compression) is good to start.  To check the valves you can just remove the valve cover and turn the engine...watch the valves move.

I suspect there is an ignition or fuel problem.  Most likely a fuel problem...a leaking gasket.

Let me know if the engine snaps back per the Briggs compression test directions.
Eric