Briggs and Stratton 21HP Intek OHV Teardown

Another video of a Briggs and Stratton Intek OHV teardown failure.

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25 thoughts on “Briggs and Stratton 21HP Intek OHV Teardown

  1. The tapered shaft that the flywheel slides onto has a keyway requiring a key (not standard square key) that is about 3/4" long and half height compared to width (3/16?)

    On mine, the key got sheered off and the keyway wallered out so that any new key would sheer almost immediately. Used JB WELD on the key in the keyway and have not have any problem since.

  2. 1:37
    Besides the four bolts (2 front and 2 rear) holding the upper housing on —
    there should have been a short (3/4") fast taper ( for plastic ) screw between the intake nozzle and the engine holding the upper cover to the intake housing (8mm? hex with slot for screw driver option)
    Not a major problem if it's missing but doeshelp keep the cover from wiggling when in use.

  3. Is it true that Briggs and Stratton uses the same size cylinder heads and other parts for horse powers ranging from 15HP to 21HP? Im looking for a compatible cylinder head and sump cover for my 17HP. Can anyone explain? Thank you.

  4. Two mistakes I saw so far, one is minor which is leaving the engine on the frame to remove the flywheel but that's just me, but the other major mistake was pulling the head bolts off. You crack the bolts little by little all away around to keep from warping the head. You warp the head and you will have big problems getting a good seal. Has for the connection rod, the worst I seen, the connection rod was broke all the way to the base of the piston. The owner ran the engine with no to very little oil in the engine and KABOOM!!! There was very little big pieces of the rod left. Surprising the cam was undamaged but left a hold in the crank case which I patched with some J B Weld, Took the case to a car wash along with a can of degreaser and cleaned the case out. He has his working lawn mower back but I bet he will keep check on his oil from now on.

  5. My 21 HP B&S is down and was told by small engine mechanic that since the push rod was bent that the head should be replaced. He said this was a common problem with Briggs engines.

  6. Underneath the flywheel is not a coil it is called a stator. 21 horsepower Briggs and Stratton head gasket blew in the same exact spot but I fixed it with some gasket maker soldering wire exhaust gasket from a 2000 Ford Expedition.

  7. I have found that as soon as I turn the motor on, the flywheel key keeps breaking. I have tried 3 keys so far, and yet after installing a new key, I have no problems turning it by hand. The deck is not even hooked up to it yet, so there's no load to speak about.
    What do you think is wrong?

  8. Alex, do you answer questions?
    I was able to rebuild my 18 h.p. B&S ohv with your video. Everything is adjusted right. I put the engine back on and triple checked the valve adjustment, but now the motor turns, and kinda starts and than sputters and backfires and dies.
    I've replaced the flywheel key that for some reason broke again, and still does the same thing.
    Any suggestion?

  9. Hey Alex,i have the same motor with broken crank and crank case, i have not disassembled it yet any suggestions, should i bother to repair it or go for a replacement, if i have to rebuild where i can get the parts ? thanks in advance, Riz

  10. Fixed it. Flywheel and Magneto were rusty -> cleaned. Also, the work somehow screwed up the Valve Clearances. So redid the Valve clearances and it started right up.

    Alex, you have one of the most useful video channels on Youtube. For $15.00 and a couple hours of work, saved hundreds.

  11. This is my Engine. I used your other videos to replace my head gasket. I did it two years ago from your videos and it blew again. Lucky I knew what to look for. Anyway. I replaced the head gasket and VCG without problem. But Mower won't start. No spark from plug. Can't imagine what could cause that. Any ideas?

  12. I would say that it overheated and the shavings from the piston took out the connecting rod. Probably was low on oil as well from the blown head gasket. Expensive neglect for sure. Nice work, Alex.

  13. looks to me as though its been overheated but that colour may have been a coating on the piston. i havent had one of the newer generation intec engines apart but it appears they have made changes. by the looks of the crank and rod it was starved of lubrication. discolouration of the lower portion of the rod and metal transfer to the crank is a sign of something going on. perhaps a lack of maintenance has come to the oil breaking down and loosing its lubricity. usually a lack of oil would result in the top main bearing being damaged too. also that head didnt apear to be blown, briggs remmedied that problem with different torque specs. great video, i love to see your teardowns.

  14. Hi Alex, interesting problem. Could it be the bolts holding the con-rod to the main journal loosened and eventually 'let go'. Clearly there would be lots of slapping and noise shaving away the inside of the crankcase or the webs shearing what was left of the con-rod connected to the piston as the crankshaft came to rest. Just speculation based on what I could see. Many thanks for posting this video. Kindest regards. Joe.

  15. That piston has to be coated, the color is too consistent throughout the hole part. Scratch it in several places to find out.

  16. Thanks for sharing the teardown, it's interesting to understand what was the issue. I know it's not easy, but if you can film with more light it will make better video;) Keep up the great work!

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