Crow Horse 8 #1 Posted May 25, 2014 (edited) Back in the fall, my B-80's K181s took a dump. Family matters and then a horrible winter didn't allow me to pursue a repair. As a matter of fact, It took me nearly a month to be able to tow it back to the house and winch it into the garage. Today I finally did an autopsy on the old Kohler. As I suspected the rod failed in dramatic fashion. Chunks and fragments in the oil pan never are a good sign. The crank looks to be pretty much toast. I have never rebuilt a small engine so I'm in new territory. My objective is to get her up and running ASAP with the least cost. Ideally, I would love to send it out and have it properly machined/rebuilt but my budget doesn't allow for that. Opinions needed here. From what I see, I might be able to replace the crank and rod to be up and running fast. Am I being too optimistic? What was found in the oil pan...... The cam appears to have no damage......... Edited May 25, 2014 by Crow Horse Share this post Link to post Share on other sites
baerpath 517 #2 Posted May 25, 2014 Crow Only way to tell is by checking it out. I would drop another motor on if it was mine but I have spares. If you decide to change it out just let me know I'll get you one of the spares Share this post Link to post Share on other sites
305 380 #3 Posted May 25, 2014 (edited) i'm no Kohler expert , but if that was my engine i'd rebuild it. that crank will need to be ground , and i see .010 under connecting rods are available . maybe get that crank measured first to see if it will clean up Edited May 25, 2014 by 305 1 Share this post Link to post Share on other sites
smoreau 658 #4 Posted May 25, 2014 (edited) That looks like aluminum build up on the crank, I would get some 300 grit emery cloth and see if you could clean up the crank. I have cleaned up 75% of the cranks I seen with emery cloth. if it is gouged in any way, you will need the crank ground. Edited May 25, 2014 by smoreau 1 Share this post Link to post Share on other sites
joel_400 59 #5 Posted May 26, 2014 Make sure to check the cam for cracks too. Ive seen it happen when the rod hits it cuz theyre hollow with a pin going thru the center. Just thought this may help you. Joel Share this post Link to post Share on other sites
gregg'shorses 77 #6 Posted May 26, 2014 I've heard but haven't tried it yet, that coka-cola is supposed to be good at dissolving that aluminum build out. Straight coke don't water it down with Cap't Morgans. Share this post Link to post Share on other sites
buckrancher 2,679 #7 Posted May 26, 2014 do not use emery cloth on the crank get a bottle of muriatic acid it will remove the alum and not harm the crankshaft Brian 2 Share this post Link to post Share on other sites
sorekiwi 761 #8 Posted May 26, 2014 Take a good look at the block, below the holes where the starter bolts on. Kohlers are notorious for cracking the block there when the rod lets go. That will be aluminum on the crank journal, once its been removed you can get a measurement to see if it needs grinding. I use the "wrong" side of 320 grit emery tape to polish cranks - use the non abrasive side with WD40. 1 Share this post Link to post Share on other sites
Fordiesel69 259 #9 Posted May 27, 2014 1. If the crankpin looks like that, it needs reground to .010 under or replaced with a used one. That will not clean up without having a knock. 2. Inspect the bottom of the cylinder wall, if there is a hunk broken out, strip the engine for parts and find another. 3. Take the cam out and look for a crack. If it is cracked in half, or looks like it is starting to, find a good used one. 4. Replace the piston, rings, and rod with a cheap set off ebay, and have the cylinder honed, or resized to the next bigger. Do NOT reuse that piston & rings, as there is a reason why the crank / rod failed. That reason would be due to oil starvation which occurred because the engine is burning too much oil, with the fact you did not check the level often enough. Rings are the most common reason for this. My last opinion would be to think about weather the 8HP is large enough for your needs. What I have found is that when I run my 875 hydro with a 32 or 36" gear drive deck, the engine is very much overworked. This will wear the engine out much faster. A comparable tractor model 855 4 speed with a 32" or 36" deck will not work the engine nearly as hard. The same goes for letting the grass get to long and having the engine at full governor for the entire job. It will tire the 8HP out long before 2000 hours. Share this post Link to post Share on other sites
WH nut 553 #10 Posted May 27, 2014 Muriatic acid and emery paper then measure the crank 1 Share this post Link to post Share on other sites
ol550 830 #11 Posted May 29, 2014 Looks like there is a scar on the cam, make sure it's ok. I have cleaned up several cranks in the past that measured up ok. Just wrap a couple layers of cloth around it and soak with the acid. Once the aluminum is gone clean it up with a strip of grey scotch-brite and have it measured. 1 Share this post Link to post Share on other sites
baerpath 517 #12 Posted May 29, 2014 Junk it. Used running motors can be had for $100 to $200 $75 to $100 for the kit (ebay) don't know if the crank, cam or block is any good Will it need machine work ? $45 a hole for boring around here plus the time 1 Share this post Link to post Share on other sites
buckrancher 2,679 #13 Posted May 29, 2014 If you scrap it do it at my house 2 Share this post Link to post Share on other sites
baerpath 517 #14 Posted May 30, 2014 How many you need Brian ? Share this post Link to post Share on other sites
buckrancher 2,679 #15 Posted May 30, 2014 how many ya got? 2 Share this post Link to post Share on other sites
rwilson 128 #16 Posted June 1, 2014 (edited) I have a few that were starved for oil as well. Might do a trade for an Air Cleaner Brian?? Edited June 1, 2014 by rwilson Share this post Link to post Share on other sites
