Small Engines (Lawn Mowers, etc.): B/S 18hp Twin wont stay running, compression issue, valve job

Question
I started my rider for the first time this year, it ran for ten to fifteen min just fine. It started to act like it was starving for fuel. It stalled, at that point i couldn't keep it running. Once it cooled down, it started and ran another ten min and again it stalled. Any thoughts?

Answer
It sounds like you have a problem related to either heat or time. Try this first. Run the engine as usual, with the fuel cap loosened off a bit (to vent the tank). If it continues to run, you will need to clean and/or replace the fuel tank vent (usually in the fuel cap). If this has no effect, you may have an ignition problem. When it quits, quickly remove the spark plugs, connect them to the wire and ground the tips of the plugs to check for spark. If it has no spark, the ignition coil/module may be failing when it is warm.  This could also be a compression issue related to heat.  If the engine needs a valve job and the tappet clearance corected, you may have compression leakage as the engine gets warm.  You would have to listen for a "whisping" sound while cranking the engine over to detect this problem.  Hope this helps.