OH NOOO...

[tommy3horse 3]

Hi fellas;

I changed the oil in my C161 yesterday and put her in the shed to sleep. I went out this am to mow, and she started with a clatter and I noticed that the flywheel was spinning out-of-round, as the motor struggled to maintain RPM's. I immediatly shut her down and pulled the flywheel screen off for a closer look. I could move the flywheel up-down about 1/4"......OH NOOO. I checked and the flywheel was tight, at least the bolt was.

I have a feeling one or both of the main bearings went south. Any opinions out there? The motor was rebuilt last year and has run excellent til today...., and yes I put oil in it after the oil change, 1.5 qts of 10w-40.

Thanks in advance for any suggestions or insight...

Tom

[bowtiebutler956 649]

If the flywheel moves up, and down you have a main bearing out. Those things usually last forever, as long as you keep oil in them. I'm not sure what happened, but you'll probably find out when you open it up. You may have sheared a flywheel key, allowing it to wear out the inside of the flywheel, but you should be able to tell whether the its play between the flywheel, and crankshaft, or is it the whole crankshaft moving up, and down, which means main bearing. Sorry to hear it, I really like the K-341's.

Matt :flags-texas:

[tommy3horse 3]

Thanks Matt, I kinda thought those things lasted forever too. I didnt bother to replace them on the rebuild.

Tom

[tunahead72 2,341]

Tom,

Not that this alone would have necessarily caused your problem, but the oil capacity on the K341 is usually specified as 2 or 2-1/2 quarts, and 10W/40 is only recommended for temperatures below 32 degrees F.

Do you know anything about the history of this engine before the rebuild?

[tommy3horse 3]

UPDATE: I pulled the motor and disassembled it this morning. I found the crank broken in half on one side of the journal. I shut it off immediately after I noticed an issue, so I may have saved the other reciprotating components. I haven't mic'd anything yet tho.

Anybody have an x-tra crank laying around? C161 w/ K341AS.

[tommy3horse 3]

Hello Tuna;

It gets HOT in missouri in the summer and I typically run 10w40, 10w30 in the colder months. The 78 C161 w/ K341AS has an oil capacity of only 1.5 qts., but I mow on some hills and that may have contrubuted to this failure.

Tom

[MarkPalmer 80]

The vast majority of the time if these engines die from oil starvation at the crankpin, they throw the rod as its the weakest link. Even so this failure wouldn't have been caused by using 40w oil instead of 30. You don't often see the cranks themselves break even under extreme torque situations. Did you see any contamination or uneven wear on the crankpin or rod bearing when it was disassembled?

-Mark-

[tommy3horse 3]

Hi Matt;

The pin was under to the point of having the machinest weld and regrind it. I am thinking that heat from welding or straightening it may have caused it to weaken.

Tom

[tommy3horse 3]

Hello;

Still looking for a new crank. The tractor is way too nice to part-out. Help.

Tom

[markjs 2]

Here's a bump Tom and don't give up. I'm sure you'll be able to find one. Wish I could help you!

[Road-Track 39]

I saw K341 cranks listed on Bill Millers site today if that helps. Sorry to hear about your 16. I snapped a rod on my 14hp C145 2 weeks ago and just picked up a C165 two days ago.

http://gardentractorpullingtips.com/a1engine.htm

[Road-Track 39]

Sorry I meant Brian Miller, not Bill (Some else I know) LOL

[MarkPalmer 80]

There are a couple in the infamous "bay" in the $100-125 range. Not sure you want to pay that much, but if no one has one to give away and it came to that or parting the tractor I would pony up the cash. As that engine is so popular with pullers, the price is probably in line with the going rate today.

Kohler K cranks are made from ductile iron that is heat treated. If the crankpin is repaired with any form of welding, the strength of the crank is compromised as you figured. Once the limit is reached with undersize rods it's best to just toss the crank in the scrap pile rather than try to repair it.

-Mark-

[rmaynard 14,896]

My machine shop spray welds cranks, but won't do a Kohler single. Owner says that every Kohler crank that he has tried had warped. Straightening the crank after a heat warp weakens it. I would bet that is what happened to yours.

[tommy3horse 3]

Thanks for the support guys!

I have located a crank that is .003 under and needs reground for $49 on Flee-bay.

The rod is STD, and maybe the machinest can hone it to ten under, as he will the crank. Its was a pretty fresh rebuild, with only 30 hours or so on it. The hone marks are still in the bore, which is std. Hopefully I can get the fire lit under the machinest, I may be able to cut grass....when it grows again.

Tom

[tommy3horse 3]

Update:

I paid a visit to the machiine shop and spoke with him about my issue. Turns out that he has offered to regrind the crank, re-size the rod and even assemble the short block gratis. He said he feels bad about what happened and wants to make it right. I may have to wait several weeks, but it will be well worth the wait.

Thanks,

Tom

[MalMac 1,328]

Holy Cow a business going out of their way to make it right and satisfy the customer. Pretty unheard of in todays business world. Guess greed has not caught up with that individual yet. Hope that machinist holds on to his morals, he is a dying breed. 3 Cheers for him!

[MarkPalmer 80]

Wow, yes finding anyone who stands behind their work anymore is very rare. Glad you found a crank and will get it running again

-Mark-

[Road-Track 39]

Glad to hear you found a crank and a good machinest. There are good people all around. Make sure you let him know he is a good one.