Small Engines (Lawn Mowers, etc.): Honda Lawn Mower model HR21SXA, honda lawn mower, arinet

Question
We have a Honda Lawn Mower model HR21SXA, purchased new in May, 1981 for $398. It has a GV150 engine, engine number 3004355.  The connecting rod broke near the end of last season, we don't know what caused it to break as there was oil in the crankcase. We installed a new connecting rod this year that we purchased from a Honda dealer. The mower ran fine and was used about five times this season for about one hour each time. The last time we used it to mow the lawn, it was hard to start, we think the engine was flooded.  Finally, it started and worked OK. Then the last time when we went to use the mower it started on the first pull of the cord, and immediately the RPMs went so high that the connecting rod broke. Any idea what caused this ? Thanks John.

Answer
Hello Jim:

From your Description it Sounds like the Internal Governor Broke and Allowed the Engine to Over Revv. Usually when a Connecting Rod Breaks, I Suggest Replacing the Crankshaft, Piston and Connecting Rod at the Same Time. When a Connecting Rod Breaks, it causes Stress on the Crankshaft, Wrist Pin (Purchased with the Piston) and Sometimes, Depending on How and Where the Connecting Rod Broke, it May Slightly Damaged the Internal Governor. I Usually Suggest Inspecting the Governor when a Connecting Rod Breaks and Replace it if Damaged. You can View a Breakdown/IPL of the Mower/Engine at this Site Addy, http://hayward.arinet.com/scripts/EmpartISAPI.dll?MF&app=ASP&lang=EN&TF=Mainfram... and Select the Catalog American Honda. Then Select the Engine File. Then Scroll Down and Select your Engine. 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