Small Engines (Lawn Mowers, etc.): 1976 john deere 300 vibration, lubricant spray, spray lubricant

Question
hello I have a 1976 john deere 300 garden tractor with a kohler motor (k341aqs)spec-71169. When I give it half throttle it starts to vibrate bad and the more throttle the worse it gets, to the point you dont want to sit on it. Do i need new motor mounts or something wrong with the engine or is that the way it is.  

thanks chris

Answer
Hello Chris:

>>I See from the Breakdown that this is a 3 Cylinder Engine.
>>I Suggest you do the Following in the Order Listed.
>>1- Change the Spark Plugs. If No Change, then
>>2- Start the Engine and Bring the RPMs Up Until the Engine Starts Vibrating. Now Using Liquid Wrench or WD-40 Spray Lubricant, Spray the Connections where the Intake can Draw Air. If the Engine Smoothes Out, then an Intake Gasket is Bad. If the Engine Does Not Smooth Out, then
>>3- Try Using the Choke to Smooth Out the Engine. If this Works, then the Carburetor Requires Soaking and Cleaning. If this Does Not Correct the Engines Vibration, then
>>4- Check the Engines Cylinder Compression. If the Compression is Low on Any Cylinder, then the Valves May Require Setting/Seating/Replacing or the Head Gasket May be Blown or a Ring Problem. If the Compression is Good on All the Cylinders, then Check the Valve Clearances.
>>There is More to Check; so if the Above Diagnostics Did Not Locate the cause for the Engine Vibration, then
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something 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. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John