K301 rod

[Ron symington]

k301 rod let go….why
piston.003 and .300 ring end gap…..smokes alot

 

[abthomas]

possible over rev ? is the governor still intact whats the 2 smaller pcs at the bottom of pic ?

 

[lpalma]

They look like governor weights to me.

 

[mgonitzke]

Probably lack of oil, or simply fatigue failure- too many hours, or there might have been a flaw in the rod casting.

Those two smaller pieces look like the governor flyweights. The nylon governor gear probably got destroyed by all the shrapnel flying around in there after the rod let go.

 

[abthomas]

They look like governor weights to me.

That's what I thought Lou, maybe the gov came apart and revs went sky high doesn't look like typical connecting rod failure !

 

[Ron symington]

I think weights are from governor

 

[mgonitzke]

... doesn't look like typical connecting rod failure !

How so? Looks like every broken rod I have ever seen...

Only thing we can really tell for sure is the rod cap bolts were not loose.

 

[gary noblit]

One of my phrases..."if it whirs and churns it wears out" yep it's broke...

 

[abthomas]

How so? Looks like every broken rod I have ever seen...

Only thing we can really tell for sure is the rod cap bolts were not loose.

most I've worked on have been seized to the crank, busted bolt and twisted cap and along with that i've also seen them snapped off under the wrist pin, but my "guess" is this one over revved due to what looks like gov weights in pic and likely was worn enough to fly apart ?

 

[Mark Evans]

k301 rod let go….why
piston.003 and .300 ring end gap…..smokes alot

You should note the oil loss was not it and it was over stress on the rod do to the revs too high, the piston end of rod should be shown also along with the bearings, piston was not low on oil either !!!!! Could tell you more from a close up of the upper rod part had failure analysis I and II, from CAT in 2002, you would not believe what can be deducted from a set of jewelers loops 10x too 30x and proper inspection !!!! Still have both two inch books on the class’s !!!

 

[Mark Evans]

Always set rpm max speed on start up and test it twice and run for an hour at 1/2 speed then retest and reset for gear mess !!!! And bearing seating on bearing tension !!!

 

[Ron symington]

Thanks for the input

 

[dkirk]

I've worked on a lot of small engines and have never seen a rod failure quite like this one. The way the crankpin end of the rod failed is telltale - looks as if it may have initiated at a rod screw thread, then crack progressed inward towards the bearing surface. Once strength was lost, the other side failed quickly in the same area. As the engine coasted down, the remainder of the rod shank was beat by the rotating remains on the crank. Keep in mind I'm making this diagnosis just by looking at the two pictures so I may be totally wrong.

 

[Mark Evans]

Anytime SIR !!! Need to see close pictures of the rod ends on both sides of the split ????

 

[dsarow]

How about a little more info on the unit,hours,has it been rebuilt,new Kohler parts or other brands.I had my K-301 overhauled,my tech recommended that rod I had in mine that came from China for cheap should be tossed,I did,I can see what could happen,I wonder if this is possible

 

[Mark Evans]

The KT17 without an oil pressure and no oil filter are ran on a tilt the high side will run out of oil and gouge up and break a rod, all the time !!!! The good one is the series II 18 magnum with live oil system and filter setup !!!!

 

[Ron symington]

It appears the governor has died
what caused this

 

[1811Cub]

That is all too common in the K series and KT17/Magnum twins. Kohler makes those out of a more resilient material, so they should not fail again. For $50 plus for the part from Kohler, it had better not!

Another option is to source a used iron gear from an older K series single. Those rarely ever fail.

 

[lpalma]

Plastic ones, Some last, some don't

 

[Mark Evans]

His was a metal one and if you check it was an overspeed, the spring on the adjustable upper setup has changed from time or reset, you always recheck the high and low on a governor setting every year to make sure at tuneup and I always just under shoot the high side setting on all engines CAT, Honda, Briggs, Kohler just by old habits for longevity !!!!! And I check mine twice a year under heavy use !