Small Engines (Lawn Mowers, etc.): Briggs & Stratton 12hp mower engine., overhead valve engines, briggs stratton engine

Question
Hi,
I have an old Rover Rancher ride-on mower, with a 12 hp Briggs & Stratton engine (cast iron sleeve). I keep the oil up to it, and possibly have over-filled it at times as it usually smokes for a while when I do that.

It needed a cutter deck drive belt replaced the other day (which I've done many times in the past), and after replacement, I ran the mower for only a few minutes. It was quite smokey, but I didn't think much more about it. Then I noticed it running quite roughly and I stopped it.

The drive belt had overheated to the point that it failed. I couldn't see any reason for it, and have since noticed some residual rubber left on the pulley surfaces. I never even smelt it to stop the engine in time.

With a new belt fitted, the whole drive train is shaking violently, and so I took the new belt back off. The pulleys turn ok and it runs smoothly without the belt fitted, but the engine still smokes a lot when running.

So, I'm not sure if there are two separate issues here, and would really appreciate your feedback.

Answer
Hello Mike:

Send me the Model and Type or Spec Numbers Off the Engine, Please. With these I can Locate the Proper Manual and Better Assist you. The Model Numbers May be Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug. Many horizontal shaft, overhead valve engines have these numbers stamped into the OHV rocker cover. However, on certain overhead valve powered generators, the equipment manufacturer installs a decorative chrome rocker cover OVER the Briggs cover. If your engine has a decorative cover, it may be necessary to remove it in order to locate the Model, Type, and Code. You can Also Use this Site Addy; http://www.briggsandstratton.com/maint_repair/BS_modeltypecode.pdf for Assistance in Locating the Model, Type and Code Numbers of the Engine. Send me the Model Numbers Off the Unit, Please. With these I can Locate the Proper Manual and Better Assist you. 1- The Engine Smoking: Did you have the Mower Tilted? If Yes, then the Crankcase Vent/Breather May be Full of Oil and Requires Manually Cleaning. 2- Vibration when Deck Engaged: A Bent Blade, a Bad Idler, Quill/Mandrel/Spindle or a Bent Engine Pulley or Crankshaft is the Usual Cause for Vibration. The #1 Cause is the Bearings are Bad and cause the Vibration, But a Bent Blade, a Bent Pulley or the Belt Routed on Top of a Belt Guard/Retainer will Also Cause Vibration. 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. Ratings and Comments are Greatly Appreciated. Thanks.

Respectfully

John