20 Most Recent Briggs & Stratton Lawn-Boy Insight Series 21-Inch 190cc 650 Series Gas Powered Engine Variable Speed Self-Propelled Lawn Mower Questions & Answers

SO ENGINE IN A CRATE OR ON A MACHINE NO MACHINE TOLD. WHy? TELL HIM BRIGGS WEB SITE HAS THE ENGINE MANUAL SHOWING EVERY PART INSIDE. I HAVE ONE FOR ALL MINE, AND ALWAYS DID FOR DECADES. START HERE https://www.briggsandstratton.com/na/en_us/support/manuals.html NO BUT THERE IS GEAR THERE. IF MISSING CAM IS DEAD IF CAM IS DEAD NO COMPRESSION AND NEVER RUNS AGAIN. HE NEEDS TO WORK oN a TRAy and not mix parts. no https://www.ereplacementparts.com/briggs-and-stratton-31q7770298e1-engine-parts-c-16758_17347_17457_218794.html

Different motors use different plugs. This chart will help you find what you need. https://www.jackssmallengines.com/Products/BRIGGS-STRATTON/Spark-Plug

Check on partsTree Repair Clinic

Should be a drain plug on the bottom of the motor remove it drain the oil replace and refill

It should have a dip stick on the motor with a full mark but if u need to know exactly try Parts Tree Repair Clinic.

On or near the carburator should be easy to see

ebay or amazon you may find one

I believe it is 0.040 on a regular spark plug gapper

I posted this for a similar question.

The large red cable from the battery should go to the large terminal on one side of the solenoid. The opposite side of the battery solenoid connection goes to the starter So now you have a heavy cable going from the battery to one side of the solenoid and another heavy cable (red) going to the starter connection. There should also be a small wire coming from the ignition switch to the small terminal on solenoid. If there are two small terminals on solenoid, ground the other one. To test the ignition switch, just turn the key and see if you get 12 volts, then you know that part is good. If not, check your ignition switch. So, back to the solenoid-----. If there are two small solenoid terminals with nuts for wires on the solenoid then the wires could be mixed up. So just reverse the two small wires and try again.

You would think they would make things easy and say on the solenoid, Battery connection here, and Starter connection here, and ignition switch wire here, but no, just nothing for the most part.

So now remember this is nothing more than a lightswitch type of a mechanism where instead of using your finger to flick the switch, we are using a small electric charge to momentarily close the light switch, in this case the starter motor, same idea.

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The large red cable from the battery should go to the large terminal on one side of the solenoid. The opposite side of the battery solenoid connection goes to the starter So now you have a heavy cable going from the battery to one side of the solenoid and another heavy cable (red) going to the starter connection. There should also be a small wire coming from the ignition switch to the small terminal on solenoid. If there are two small terminals on solenoid, ground the other one. To test the ignition switch, just turn the key and see if you get 12 volts, then you know that part is good. If not, check your ignition switch. So, back to the solenoid-----. If there are two small solenoid terminals with nuts for wires on the solenoid then the wires could be mixed up. So just reverse the two small wires and try again.

You would think they would make things easy and say on the solenoid, Battery connection here, and Starter connection here, and ignition switch wire here, but no, just nothing for the most part.

So now remember this is nothing more than a lightswitch type of a mechanism where instead of using your finger to flick the switch, we are using a small electric charge to momentarily close the light switch, in this case the starter motor, same idea.

check for a blocked main jet in the carby or blocked fuel line to the carby

First of all, is there an air filter on the motor? Second, what does it look like. How long has it been since it was changed? Limewise with the oil. I would run a compression test on it-it's a pressure guage with a hose attached.that will have a threaded fitting to screw in the spark plug hole You set the guage on the closest spot where it'll stay. Turn the engine over a few revolutions. Whether you turn it over 3 times or 30, it will give the same reading. If it is below 60 lbs pressure, the motor is worn out. Especially with a dirty air filter. You can put another set of standard rings for that model of engine or...just go get a new one! Haba. Hope i helped

This could be a number or items from no spark to a faulty carburetor, a plugged up air filter, valves out of adjustment, poor gas, faulty spark plug.

First, see if your getting spark, how about taking the wire off a plug(s) and holding it about 1/8" or so away from the plug with some masking tape while you crank the engine. You should be able to see the spark jumping the gap, it helps if it is not too light outside. If you attempt to do this with your hands, you will get a spark jolt, it hurts, so use the tape and remember, the engine could start so proceed with caution.
If you have no spark there, then you ignition or magneto is faulty. This would be unlikely in the broader scope of things. You will likely get spark. Make sure the plug is clean, take it out and inspect. If it is covered in gunk well clean it. It will smell like raw gas but you already know that. Change the plug if in doubt.

Remove and clean and replace the air filter.

If you have spark, and a clean filter it is likely a carburetor problem, Depending on the carb, it could be the choke is faulty or, as per the below.

Depending on what model you have there is a float assembly in the carburetor that stops the fuel from flooding the carb and air intake. The gas tank is higher then the carb right, so if you dont have a mechanism for stopping the fuel from leaking out the hole that goes into the engine, it will all leak out right, as into the fresh air intake because its easier than going into the engine. So, there is a miniature float assembly, sort of like your bathroom toilet float to stop the water. Well there is a small wedge type needle that seats into a hole and it is attached to a float. As the gas rises in the bowl, it pushes up the float, sealing the gas into a chamber, as you use more gas, the float lowers and more gas goes in. So ,there is dirt jammed into the float bowl sealing needle, just a little, thats all it takes. So, shut off the gas somehow, hopefully you have a valve, or squeeze the rubber line, then undo the float chamber, its one nut on the bottom. Clean carefully. The needle, little spring and float assembly are delicate. Also, the needle could be worn from engine vibration, so it may need a new needle. It would help if you described the engine and carb though.

I posted that as a solution to another problem, but yours may also be the valves need adjusting. Depending on the amount of hours, say over 200, then the valves timing will likely be off a bit. Check the clearances with a feeler gauge, it is not as difficult as it seems. Check your Owners manual for the clearance at top dead center. TDC is when you take the plug out and watch the piston arrive at the top of the cylinder through the spark plug hole when you are turning the engine over (do this by hand, battery off. Make the adjustments with the valve cover off. Follow the instructions.

Hope some of this helps.

It does not have a drain plug. You can remove the dip stick and tilt the mower to pour out the oil, or you can use one of those hand pump syphon units to pump it out.

probably a carb problem if it will start but not carry on running, possibly dirt in the float bowl

which cable??

Are you running it with the choke on? Also if the air filter is dirty it will do that as well. Black plugs means it's getting too much gas and is not getting the proper air to burn properly. Some engines if you rev them up with the handle right as fast as it will go automatically the choke is on.

Is the choke stuck on? That could do it. Does it rev high enough ? May need adjusting. You say you added oil was it low enough you have almost seized the engine. Just a thought

First of all clean all the gunk from all the drive wheel areas and where the drive belt operates as well as the pulleys Check the belt as it could be broken or stretched. Maybe should replace the belt and lubricate all the working areas as well as wheels. Check the shear pin as well.