Small Engines (Lawn Mowers, etc.): Valve Adjustment (Take 2)?, piston valves, valve adjustment

Question
John,
I needed to start a new thread since I asked the maximum number of follow ups.
I worked on the mower today.  I changed the fuel and fuel filter to make sure that this didn’t lead to other issues.  I took the cylinder head covers off both cylinders and cleaned the piston, valves, and cylinder.  There were some carbon deposits but not much.  I noticed that both pistons hit top dead center at the same time.    I also noticed that the valves on the one cylinder weren’t opened or closed at the same time as on the other cylinder.  I don’t know why I thought the pistons would work opposite each other and if they work together that the valves should be open and closed in a similar fashion on each cylinder.  Back to the mower.
I put the motor together and found that the starter was able to turn the flywheel around the entire rotation and at a quick pace.  I let the starter turn the flywheel for about 20 seconds at a time to make sure it was rotating smoothly.
I added some starting fluid and started it up.  It was running smooth and sounded good.  Then I heard a noise as though something loose was rotating in the motor.  I thought it was coming from cylinder #1 so I opened it up.  I found that I could rotate the flywheel but it got caught up at one place.  As I rotated the flywheel, the valves moved but the piston doesn’t.  I don't think I could repair the rod/piston myself.  I don't know if it is worth it to have it repaired.
Do you have an opinion concerning the decision to repair or replace a mower?  This is an 8 year old mower.  I don’t know any repair centers although there are a few reputable ones in the area.  My concerns are that even if we replace the motor, there are other parts such as the electrical and transmission that are already 8 years old and may require repair in the next few years.  I think I would replace this with a mower costing between $1000 and $1200.  I haven’t looked at motor replacement costs such as a new motor and labor.

Thanks for any input.


Answer
Hi Keith:

From your Description and the Fact the Piston is Not Moving, it Does Sound like a Connecting Rod has Broken. If you can Purchase a Mower for the $1000 - $1200, then I Suggest you Do So. The Cost of the Connecting Rod and Labor will be $650 - $950 Depending on the Area Labor Prices. A New Engine and Labor for Installation will Cost About the Same as the Connecting Rod Replacement. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John