Small Engines (Lawn Mowers, etc.): 3 hp briggs, hp briggs, adjustment screws

Question
QUESTION: hi my 3 hp Briggs wont start i have done a head and gasket replacement to bring up compression from only 60 lbs added electronic ignition i now have 90 lbs of compression, lots of spark and gas is getting into the cylinder it is an older motor and their are no cracks in the blocks have not checked rings but their is no gas in oil. and it will fire occasionally but wont start at all. any ideas?

ANSWER: Hello Norm:

By Older, Do you Mean this Engine May have a Point Set Under the Flywheel and Not Use Electronic Coil/Magneto/Ign Module? *Send me the Model Numbers Off the Engine, Please. With these I can Locate the Proper Manual and Better Assist you.* If the Fire is Intermittent, then I Suggest you Replace the Point Set with a Nove Ign Module to DO AWAY WITH THE POINT SET. The Nova Cost a Small Amount More than the Point Set, but will Give Less Trouble than the Point Set. Will the Engine Start and Quit if you Pour a Small Amount (1oz) of Gas Into the Carburetor Throat and Try to Start the Engine. If No, then the Point Set or Coil (if Magnetron Ignition) is Most Likely the Cause. If the Engine Does Start and Quit, then  Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl, Float Pin, Float and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. 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 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: hi john, the motor did did have a point set that i have disconnected and i now use the electronic ignition made by Stens it is a mega fire 2 model number 440-465 it is set up as if it were the points and grounded to a piece of mettle attached to the head. i was unable to locate the model number, but i found a small sticker that said 2 hp at 3600 rpm unlike the flywheel cover with a 3 hp rating and on the under side of the original motor head that i replaced i found the numbers 8B. the motor will not start with gas down the carb i tryed again to day and after 60 pulls it did not even fire i also tryed gas straight down the hole after with no luck. i am not sure how much compression the motor needs i am using a gasket of another motor of the same type that i use for parts so my gasket may still leak. it is also the old style of carb that is mounted on the gas tank. i am guessing the motor is 20-30 years old. still tones of spark.  

thanks

Norm
ANSWER: Hello Again Norm:

No Worries. The Model Type and Code Numbers Are Stamped Into the Blower Housing Above the Spark Plug. If you have 90 PSI Compression, the Engine Should Fire and Run. The Stens Replacement is a Good One. I Started with the Nova ll and have Seen the Stens on Other Mower in the Shop. As Far as I Know, they are as Good as the Nova ll. The Reason for Requiring the Model and Type Numbers is the Carburetor Diaphragm. I Remember the B&S Part Number for the Dual Pick Up Carburetor Diaphragm (#391681), but I can Not Remember the Single Pick Up Diaphragm Part Number. Since the Engine has Fire, and Doe Not Start and Run when Gas is Poured Straight Into the Carburetor Throat, then Remove the Flywheel and Check the Flywheel Key. With 90 PSI Compression, Gas in the Cylinder and the Plug Firing; This Engine Should Run. Now if the Flywheel Key is Damaged, then Plug Timing is Off and the Engine can Either Run with a Power Loss or Not Run at All. Make Sure you have a Blade or Counter Balance Weight Firmly Attached to the Crankshaft. Very Few of these Engines Were Designed to Run Without a Blade or Counter Balance Pulley Attached to the Crankshaft.  Also, with the Model Numbers I Can Locate a Breakdown of the Engine for you to View Online. You can try this Site Addy if you Locate the Model and Type Numbers. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. Engine Parts are Still Available for this Engine at Some of the Site Addys I have On File. If you Can Not Locate the Parts, Just Let me Know. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John



---------- FOLLOW-UP ----------

QUESTION: tryed new key and a dirrent fly wheel still no firing. and i was still unable to locate any numbers if you mean blower housing above the spark plug on my motor their is no cover on the spark plug it is a non slanted horizontal shaft with no cover on the top only on the side over the fly wheel, no numbers on there ether. i have been reading my ICS books but they all say the motor should be running perfectly. i rechecked my governor and it seems right according to the diagram. could this be something internally wrong with this motor? the last time it ran all i had to do was file the points and it worked fine, idled correctly ran wide open fine with no knocking then after around 3 hrs of running i shut it down came back to it the next morning and nothing, no spark and was unable to repair the points so this year i added the electronic ignition and got the spark back. but after the head and gasket replacement i still have no firing.  

much thanks

norm

Answer
Hello Again Norm:

You Do Not have the Old Point Set Hooked to the Electronic Ign, Do you? If you are Still Having Problems and the Flywheel Key is Good, then Carburetor is Clean and the Compression is 90 PSI, then the Internal Timing for the Cam and Crankshaft has Jumped or the Valve Clearance needs to be Reset. On the Older Engines, you have to Remove the Crankcase Vent and then Remove the Valve Spring Keepers to Remove the Valves. The Tip of the Valve Stem Is Lightly Ground Down Until the Proper Clearance is Aquired. The Valve Clearance is .005in - .007in Intake and .010in - .012in Exhaust. The Model Numbers Not Stamped Into the Blower Housing (Flywheel Cover) is Unusal. All the Older Engines Model Numbers were Stamped Into the Blower Housing. Use a Wire Brush and Check the Area on the Blower Housing Directly Across from the Plug Or Across from the Muffler. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John