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B.Ikard

Kohler KT17-19 series 2-why do they break rods???

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B.Ikard
Gents, Was looking for some knowledgeable feedback on why these engines commonly break RH connecting rods? In the last month I have seen at least a dozen of these engines with holes in the block-aLL RH side. Back in the mid 80's we sold a pair of 7117 Tractors-both came back with ventilated blocks in less than 100 hrs. I'm looking at a 917 rolling chassis now-guess why it is a rolling chassis? RH rod fragged the block. I don't buy the theory of uncovered oil pump pickup tube in every failure,or improper PM even tho Kohler preached it to us back then. IMHO these engines have a design flaw-it happens when engineers rely on faith too much. Has anyone found it or know how to correct it? I wouldn't mind building it back if I could prevent another thrown rod.. As allways any advice, experiences or comments are welcomed, Brent


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rsnik
I have always heard it is the series 1 that throws the rod and the series 2 is OK. The commonest theory I hear is that oil starvation occurs on slopes. I don't know what the actual percentage of these engines that throw the right rod is, but is suspect it may be more than 50%, or in other words most of them. I can't figure out how Kohler avoided having to recall all the engines and replace them.

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olcowhand
They had some sort of spray lube for the rods instead of full pressure lubrication. Slopes affected the spray lubing on any slope of much angle. If you have a flat yard, then they will usually last pretty good, but they'd not last a day on my place!

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Dark
olcowhand is correct, in the series 1 engines the oil was pumped to the camshaft then sprayed down on the rods, the series 2 was journaled through the crankshaft. oil starvation was caused from oil level to long between oil filterchanges (low oil pressure) the way the sprayers worked if it was low on oil it would drop most of what it could on one rod and starve the other. If you need the repair manual for it go here ! they are free PDF files http://www.kohlerengines.com/service/manuals/manuals_results.jsp

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B.Ikard
Thanks for the replies: I'm familiar with all the design changes and theories that were built in the series 2 engine. My uncle was a Simplicity dealer in Nashville TN during the period of the series 1/2 changes and I worked in his service department. Our Kolhler distributor rep preached like Jimmy Swaggart that they got it right on the KT series 2 version :D The problem did not go away with the series 2 engine... I was just "fishing" for an under the table permanent fix that might be known or "leaked out" Thanks, Brent

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MikeES
Brent, IMO the answer is oil reservoir. I believe the later series II and the Magnums with the oil filter were much more reliable. More oil and more oil cooling with the filter.

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dlcentral
why wasnt this extensivley tested before put out to the public ,,co. greed as always i guess.for that you get foreign engs which from what I hear are pretty reliable,All the amer co's that were being complacent in the -80's mainly,are now are reaping the consquenses of their in actions in the '90's- imo,'00's look at us auto industries

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Dark
Almost most Marketing stradigies have a deadline the engine was tested and sent out to the public R&D continued hence the reason it was updated EG., Microsoft sends out a working Operating System and keeps R&D and follows with patches,updates,and such. Companies can't afford to be without the "new and improved" or their competitors would leave them in the dust EG.,Cyrix processers for computers. AMD and Intel kept up with R&D Cyrix sold out and became a mainstay with IBM.

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D-17_Dave
IMO, which ain't much, it only makes sense that these engine would give trouble since the #1 journal is the last to get the oil flow from the pump. If any bearing gets worn allowing the hot oil to flow back to the sump and not make it to the rod it will blow that rod. To me it's the stupidest thing Kohler has ever done. That is until the belt drive cam engine.lol To me the only way to overcome this weak point is to drill out the crank between journals 1 and 2 so the oil goes straight to both rods first. What I don't know is how this may effect the strength of the crank. But it can't be worse than the results we see now.

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GregB
Just a few things to remember. Few business's design things to last forever. Anything with rotating parts will wear. Most of the engines we are running today, have what ? millions of cycles, billions of rotations in thier life. I think Dave hit on a good point, as things begin to wear past ideal or nominal sizes, clearances get larger, oil pressure drops a little, a little more friction perhaps, then wear. I seem to remember Al commenting on the Kohler twins and their use. If I remeber correctly he ran quite a few mowing hills etc. Recommended frequent oil level checks and changes. Of course back to my earlier point, that was when the engines were all "new" and had not seem an wear, sizes were factory design clearances. I'm sure if the original designer was asked if he thought they would run forever, he would be surprised they were still running. Aluminum rods on steel crank? Always has surprised me! Enough soap box GregB

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ghwrenchit
Hello All, New kid on the block. now you have me worried. I just bought a 1991 Sovereign (probably paid to much...) but had to have it. Replaced the bevel gear box, and a few other do-dads runs great. My dad has the same but is a 2000 model with power steering. How do I tell if it's a series II, year? If so, is there anything that can be done to extend the engine service life "before" unintended crankcase ventilation? Thanks Greg PS: My new (to me) garage toy is replacing an H16 Bol`en$ (currently for sale), but I did'nt want to say the whole word here C

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PhanDad
Greg, I'm far from a Kohler expert, but I know the series II engines have "Series II" written on the air cleaner. I would also think the spec number would be different, and hopefully someone more knowledgeable than I can tell you. I picked up a GTH-L with Series II KT-17 in it. PO ran it with a plugged inlet screen (minimal cooling air) and low on oil - sure death to a KT17 and most other engines. You have a great tractor. My understanding is the Series II is a good engine IF you keep oil in it and the cooling screen/fins clean.

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ghwrenchit
Just found the KT17 Series II manual. It was issued 4/87. One would think the series II replaced series I completely at some point in Series I inventory depletion. I can only cross my fingers before getting home that in 91, simplicity was using all Series II's. Makes one wonder which tractor mfg gobled up all of the series I inventory from kohler cheap to get something out there.... Thanks Greg

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B.Ikard
UPDATE: I tore the engine down today and RH rod broke due to siezure on crankshaft. Obvious lack of oil.... Interestingly all other bearing surfaces looked great. Cylinder walls were not scored, etc. The rod big end came apart, wiping out camshaft, breaking tappets, and beating up block. This engine had pressure lube rods, as there are oil galleries in the crankshaft. Probably a worn bearing upstream hindering oil flow- Brent

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BLT
Now how many failures occurred within the warranty period? And then, how many failures were to customer neglect? I would guess that question number two would be the correct. People for the most part don't take care of lawn and garden equipment, much less read the book. And when they do have a failure, they do STUPID things like fill the crankcase with oil after an engine seizure, maintain they took good care of an engine while you chisel out impacted grass on the block fins with an air chisel and lastly couldn't figure out what broke his mower wheels until you look at the mower blade witch has the shape of a boomerang and ask him if he has noticed anything unusual with the mower and his says "nope, not until wheels fell off". I am not jumping in bed with engine people but consumers are pretty creative when they think manufacturer is at fault. And then how many failures were there versus how many produced. Nobody knows now or really cares, I guess. I also know that engine people have their problems from time to time. The S-60 engine had a rod problem a few years ago and "lunched" quite a few thousand blocks before problem was finally nailed down. There were about as many service support engines built as there were production units as the failures were in the warranty period. However product has been a real work horse now with an estimated guess of 1.25 million engines built over a 22 year period when it will be phased out in 2010.

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B.Ikard
Bob, I have to agree with you on the 60 series engine (Good design, good engine). It wasn't around when I worked on trucks as a living. I heard Deere and Detroit got together in engineering the S60 but was unsure. A friend is shop manager for a large grocery store chain that maintains a fleet of trucks. He has been a Detroit convert since the S60 and they seem to have problems more often with other makes-particularly the older Volvo built engines. I found it odd the series 60 was overhead cam. It was about time the old 2 cycles were replaced, a design that dates to the 1930's. Charles Kettering was a genius...a lot of tricks/skills on rack/governor set up & injector/valve adjustment is a dying art. I have been promised a job @ Williams DD working the 2 strokes, still very common in fire fighting equipment around here as all the "pros" are retired or in management. I learned my trade on them, still perk up hearing a 671 wind out in a truck, but they just did not have the lugging power of the competitiom IMHO. Brent Here's some music for 2 stroke Detroit fans: http://www.youtube.com/watch?v=OJfCqYsV1_o http://www.youtube.com/watch?v=klRq8D97S8c

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tillerman
Maybe i've just been lucky but I bought one of my 917 which was made in 1980 from a fellow in Indiana about five years ago. He had it for about 2 years before I got it. He said the fellow he bought it from had just put new rings in it before he bought it.His place was definitely not level and he said he mowed about 2 acres every week.I have about 3 acres and some of it is on such a slope you have to ride on the side of the seat to give enough traction on the upper side. I read about this problem on slopes early on and I keep the oil checked about every hour or so to make sure it is full. I try to make lands so I dont keep it on one side too long. So far it doesn't use any oil nor have I had any engine problems. I mow about 2 acres also. I think if you are really diligent in care it will last.

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BigSix
Brent, Those YouTube shifting vids were AWESOME! Reminds me of when I was a teenager, and rode with my Dad on a trip down to darkest NJ, to pick up some trailers. Two or three other guys drove their rigs, while I rode with my Dad. One was a "Cornbinder" (International) that had had the governor "let out" to something like 3,300 RPM (I could be wrong on that value, but I believe the std. redline was 2,750? I bet D-17 Dave can confirm/deny? By comparison, I think the Mack revved until only 2,250, and had a low end of 1,250. I can remember being in my father's twin screw Maxidyne (straight six, four stroke--Mack engine?) and leaving the toll booths next to that modified Cornbinder. MAN did that DD rev!!! It was actually more viscious and aggressive than what is depicted in that video, but I noticed the video driver had a vehicle in front of him at least once, so that might have slowed him down some. Then again, the vid driver's DD may be stock, whereas this guy's engine had "had the rack let out." Good times! Thank you--I'm going to play these for my Dad, on his computer. I think he'll get a kick out of it, since he restored and collected antique trucks until last year (he's 82). Thank you so much! Peter

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B.Ikard
Peter, Glad you/others enjoyed it-sometimes when I am having a bad day or bummed out I play those clips and it puts a smile on my face. It's the shred of kid left in me.:D I would set a little 53 series to 3000 as they had less mass going back and forth. I never set a 71 series much past 2800 (the truck in the pic). I tried to stay with the "book" as if it came apart I wore the blame. With that 2 cycle design it sounds like a jet engine @3000. Much different sound than other make engines, but these generally had less lugging power than the 4 stroke designs. Brent

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BLT
If you wnated to see a crank stretch try a "71" at 2800 RPM, too mudh mass and the valves would start to float and cause piston damge. The "53's" although rated a 2800 RPM full load load were notorious for dropping valves and the puching the bent valves back in the head. With all that in mind, people were still buying them as they had that magic word forty years ago, "Diesel"

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