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Point and Carbureator settings on 8HP Briggs & Stratton


Ray Odom's Avatar
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02-06-04, 01:34 PM   #1  
Point and Carbureator settings on 8HP Briggs & Stratton

I have an old Sears mower with an 8 HP Briggs & Stratton engine. How do I set the points and adjust the 2 screws on the carburetor? One screw is in the throat while the other is under the bowl.

Also, where do lthe 2 wires connect that come from the alternator (generator?) ?

 
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cheese's Avatar
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02-06-04, 11:14 PM   #2  
Hello Ray!

The points, if equipped, are under the flywheel. Engines haven't come equipped with points for about 20 years now, so you might not have them if your engine isn't that old. You'll have to remove the engine blower shroud. Look at the coil. If it has a wire that disappears under the flywheel, you have points. You will need to pull the flywheel and remove the 2 screws that hole the points cover on. Then rotate the engine to TDC and set the points to .020".

The idle mixture screw goes into the body of the carb from the top. It should be turned clockwise until it lightly bottoms out, then backed out 1 1/2 to 2 full turns. The screw under the bowl is the high speed mixture screw. Run the engine at full throttle while adjusting this. Turn the screw in until the engine begins to surge, spit, and/or die. Then back it out, while counting the # of turns, until it begins to stumble and spit. Divide that number of turns by 2 and turn the screw back in that many times. This should get it running well, and may or may not require fine tuning.

Hope that helps!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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02-07-04, 02:25 PM   #3  
Originally posted by cheese
Hello Ray!

The points, if equipped, are under the flywheel. Engines haven't come equipped with points for about 20 years now, so you might not have them if your engine isn't that old. You'll have to remove the engine blower shroud. Look at the coil. If it has a wire that disappears under the flywheel, you have points. You will need to pull the flywheel and remove the 2 screws that hole the points cover on. Then rotate the engine to TDC and set the points to .020".

The idle mixture screw goes into the body of the carb from the top. It should be turned clockwise until it lightly bottoms out, then backed out 1 1/2 to 2 full turns. The screw under the bowl is the high speed mixture screw. Run the engine at full throttle while adjusting this. Turn the screw in until the engine begins to surge, spit, and/or die. Then back it out, while counting the # of turns, until it begins to stumble and spit. Divide that number of turns by 2 and turn the screw back in that many times. This should get it running well, and may or may not require fine tuning.

Hope that helps!

 
Ray Odom's Avatar
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02-07-04, 02:29 PM   #4  
Originally posted by cheese
Hello Ray!

The points, if equipped, are under the flywheel. Engines haven't come equipped with points for about 20 years now, so you might not have them if your engine isn't that old. You'll have to remove the engine blower shroud. Look at the coil. If it has a wire that disappears under the flywheel, you have points. You will need to pull the flywheel and remove the 2 screws that hole the points cover on. Then rotate the engine to TDC and set the points to .020".

The idle mixture screw goes into the body of the carb from the top. It should be turned clockwise until it lightly bottoms out, then backed out 1 1/2 to 2 full turns. The screw under the bowl is the high speed mixture screw. Run the engine at full throttle while adjusting this. Turn the screw in until the engine begins to surge, spit, and/or die. Then back it out, while counting the # of turns, until it begins to stumble and spit. Divide that number of turns by 2 and turn the screw back in that many times. This should get it running well, and may or may not require fine tuning.

Hope that helps!

What is the best way to determine TDC and what about the generator wores?

 
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02-07-04, 02:31 PM   #5  
Thanks for the info. But what is the best way to determine TDC?

Also, How do I connect the alternator(generator)?

 
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02-07-04, 11:37 PM   #6  
Take the spark plug out and place your finger over the plug hole. Turn the engine slowly by hand. When you feel air trying to push past your finger, you are nearing TDC. Take a piece of wire or something similar and put it in the plug hole until it hits the top of the piston. Continue turning the engine until the piston pushes the wire out to it's farthest point. That is TDC. (Top Dead Center).

One of the wires coming from the alternator has a "bump" in it just before it goes into the connector. This wire should connect to the positive battery cable, either at the battery or at the solenoid, whichever you prefer. The other wire just connects to headlights (if equipped).


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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