Top 20 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

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

This is a hard one to diagnose without seeing it but it could be a sticking float or a stuck open valve. If you have good compression you can eliminate the valve issue. Be careful checking the float that the inlet needle doesn't fall out.

disconnect the spark plug turn the mower on its side and inspect the drive belt on the pulley above the blade (on the crankshaft) it may have a shroud over it. Also there is a small gear case that maybe dry that the belt drives, that goes to the wheels, Also try lifting the drive wheels up off the ground and engage them and see if it still does it. if it stops once lifted it might be the bushings on the axle its self.

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

Any good grade of SAE 30 will do fine unless on cold weather operation..then SAE 10-30 ..

the dip stick twists out, and sometimes are tight, or hard to turn. be sure and replace it as tight as you can, back presure in the crankcase will blow it out if it's not tight

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

if has a two cycle engine check for carbon build up in exhaust port if its a briggs and stratton check compression it sounds like one of the valve seats has come loose if it is have to take in to fix about 80.00 dollars then it comes down to hoe old is it do you want to spend that kind of money and not by a new one you will have to think this over because you can bet some shop going to over charg you like i said 80.00 no more than 100.00

which cable??

These machines have carb and coil issues. Check for fire. Nice when new, but once a little age creeps in, the engines just aren't that sturdy. Sorry, but as a small equipment mechanic, I don't recommend Lawn Boy. Next time, buy another brand.

Check on partsTree Repair Clinic

Any auto parts stor will have pre made one available and many sizes to choose from

Your valve lash is out of adjustment causing the exhaust Valve to stay closed longer then it should, keeping compression in the cylinder trying to exhaust while in the compression stroke..not a hard job but must be done...good luck

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

On or near the carburator should be easy to see

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.

ebay or amazon you may find one

Can you get me the lawn boy Model #

Manuals Parts Engine