Briggs engine – No compression diagnosis and repair

My neighbor gave me this push mower. He told me that it ran fine when he parked it, but that it had sat for about 2 years…outdoors!
He told me that he believed all it needed was a carb diaphragm and gasket and it should be fine…ohhh, and that he had messed with the ground wire on the back of the engine. Well, I ran a cylinder leak down test and discovered what I thought were bad valves. Turns out, it was just a bad head gasket. All in all, I have about $50 in new parts for this. But, it runs good now.



22 thoughts on “Briggs engine – No compression diagnosis and repair

  1. The good thing is that it runs…I often run a 2 stroke mix fuel in a 4 stroke mower that has been sitting for a long time until it has had a few heat cycles..Especially if it has had ethanol in the fuel…As for a inch pound torque wrench to do the bolts up…well lets say that a well trained arm knows what tight enough is…lol…BTW…our push mowers don't have a cutout bar.

  2. yeah i know what you mean my mower sat for about 3 years and has bad compression it dies quite a bit and only starts with starting fluid i got it to start and run on propane just using stuff around the house i didnt have enough money for a carb replaced the kill cable and soldered on a new spark plug boot and now she runs just dies a few times mowing the lawn

  3. I have almost the same exact mower I picked up for free today.
    The oil is nice and clean and no compression, the piston is moving back and forth so its not a broken rod.
    What do you think caused the head gasket to fail?
    I am wondering if this is the case for mine as well.

  4. I'm going to re ring my 1980's model B&S powered push mower as it is hard to start & Lacks power,it also burns oil when the engine is cold.
    On a dry test, it reads 97 PSI on the compression tester,on a wet test with oil it reads 120 psi so the rings are slightly worn.
    Replacing them will give the engine a new lease of life.

  5. number 1 rule, before messing with a cheap mower do a compression test. if Gage reads zero, get rid of it. don't spend $$ on a mower that's worth $60 in good running condition

  6. I had the same push mower from Leavenworth ks and I can assure you those are excellent mowers! Maybe was neglected and you have to replace the gasket, next time before you make any investment check for comptetion if there is no competition and the cilinder is damaged is beyond repair! I had to learn on the hard way sane as you

  7. Great video. Nice to see what the lawn mower looks like when it has been torn down before I have to do it myself. I seem to be having a similar issue I hope it is JUST a head gasket!


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