ka9bxg Posted June 10, 2006 Posted June 10, 2006 I was out cutting the grass today about 5 minutes. I was going along well and then there was a noise like I ran over something ,engine stoped.Tried to start it and nothing would happen.I can tell you that a 7116 is not a easy tractor to pull to the garage. Well pulled the head and sure enoph the piston is not moving. Took the engine out and took the pan off,What a mess the rod broke in half hit the cam and bent it wiped out the govoner. There was no damage to the crank ,rod was not worn or loose.Bolts were tight. I don't know what caused this,never had a briggs do that to me before.Good thing I do have another engine out of another tractor.I do have another block for the parts but it still will need a rod. Bummer of a day when this happens.The good thing is I am going to a tractor show on Sunday.Bob
jlasater Posted June 10, 2006 Posted June 10, 2006 Any rod material on the crank journal? If so, probably seized up. Possible the piston pin seized and put a sideload on the rod as well.
ka9bxg Posted June 11, 2006 Author Posted June 11, 2006 Rod is perfect no sign of problems on wrist pin either. No sign of anything wrong. The show was in Plainfield near Coloma, It was a little cool,there were a lot of gas engines and some garden tractors but did not see any Simplicity or Allis tractors there. Bob
maxtorman1234 Posted June 11, 2006 Posted June 11, 2006 So when you say the rod broke in half, i guess you mean the rod was still attached to the crankpin,thats how you knew they were tight. How old is the engine, sounds like it must have been a faulty rod if the bolts were tight and no material on crank.
AC808 Posted June 11, 2006 Posted June 11, 2006 WOW..had almost an identical thing happen to me 2 weeks ago...Took the pan off..end cap and bottom of rod had seized to crank...probably gonna work on that this winter...
patrician12 Posted June 11, 2006 Posted June 11, 2006 It is possible for the rod to break in half if the engine over revs.The stress on the rod grows exponentially with rpm.Aluminum can't be pulled apart.Just try to pull a gum wrapper or aluminum foil apart.It can't be done.The tensile strength of aluminum for weight ratio is mindboggling.Here is the down side.It compresses with no effort.I believe most rods fail on the down stroke that's why on air cooled engines rarely is the head damaged.On autos with steel rods when they give out they usually go in orbit through the head or the block itself.
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