Repairs YS4500 won't start

[jewisian]

My craftsman YS4500 model 917.287241 won't start. It turns over but won't start. I've replaced the carburetor, spark plug, fuel filter, and checked the safety switch under the seat. Any ideas of what I check next?

 

[bertsmobile1]

SOP.
Get an in line spark tester and a can of starter fluid.
Hook up the spark tester and remove the air filter so you can squirt the starting fluid down the carby.
Crank the engine and give a squirt while watching for a spark .
No spark then you have an ignition problem
Starts & runs only while you are spraying the starter fluid then you have a fuel problem.
Has a spark but still no start then you have a valve timing or spark timing problem
Check the valves , watch them going in & out while you feel the position of the cylinder with a stick down the plug hole.
Check the ignition timing by removing the cover and and looking at the flywheel key.

 

[jewisian]

Thanks I'll work on it again tomorrow. I appreciate the help.

 

[jewisian]

Checked the valves and nut on the intake had backed out. Set to specs and the mower started. Thanks a million for your help.

 

[mechanic mark]

CRAFTSMAN TRACTOR Parts | Model 917287241 | Sears PartsDirect just information including wiring diagram

https://www.briggsandstratton.com/us/en/support/manuals/results?NTT=331877-0805* engine information