KC9KAS 4,741 #1 Posted November 16, 2015 I have a couple of K301 engines that are in need of rebuilding.Both knock really bad, but do run. One of them was actually "seized" up (supposedly) when I bought it.Just wondering if crankshafts can be purchased in the event mine are shot.Neither engine has been disassembled therefore I don't have any idea if the bore needs worked on or not, but I know a shop that can bore it if necessary.Just wondering what kind of expense I can expect to rebuild one of these engines. Share this post Link to post Share on other sites
953 nut 51,717 #2 Posted November 16, 2015 Just because it is knocking doesn't mean it needs a crank, but if it measures bad you can get good used ones. I have gotten a couple of good used cranks from sellers like "Joe's" on for a lot less than having one turned. As long as you are dealing with a vendor that has a good reputation you will be OK. Some times the crank will have a deposit of aluminum from the rod on it, if that is the case a little muriatic acid will clean it up for you.Engine rebuild kits on from bakt4kids are quite good and run $90 to $150 depending on how many components you need. 2 Share this post Link to post Share on other sites
tractorhogg 611 #3 Posted November 16, 2015 It really depends on how good of mechanic you are and how good a mechanic the shop tells you they are. That will determine how long, or if, the engine will last. I will send my engines to Brian Miller at A-1 Machine shop up near Columbia Missouri, for 500-600 dollars he does a COMPLETE factory rebuild, parts and labor. I venture to say Brian has done well over 1,000 engines, both for pulling tractors and owner/users. That kind of expertise is well worth the money considering you will be getting better parts and better expertise and tools used to do the job. I used a top rated machine shop in Tulsa Oklahoma and had to return the engine three times because they didn't understand how to shim the crank even after I supplied them a complete manual. The engine smoked and the rings never did seat, i ended up tearing it apart myself and finding the piston and rings were installed wrong, they never even looked at the manual. If you do decide to do it yourself, I would opt for the good kohler parts on the piston, rings, and connecting rod and if you can save some money on gaskets with aftermarket no big deal. The way I figure it, is that I would rather pay a little more to have it done right than to do it twice or have poor work destroy the motor. I can see putting .0003 oversize rings on a engine that is only a few years old, but with a ton of hours, but just putting rings in a 40 year old engine is ridiculous. I have had several "mechanics" tell me that they looked at the bore and it was slick as a whistle and didn't need nuthin, yeah that because the only thing between the rings and cylinder wall was oil. Crankshaft can be turned under size or built up oversize, very few need replaced like a automotive crank, because the crank is steel and the connecting rod is aluminum, most times acid will burn the aluminum off clean, but the actual wear has to be mic'd, as does the cylinder walls. Also do NOT forget to replace valve guides or replace or regrind valves and seats. I have 14 pre 1979 engines that have never been rebuilt, a good job will be the last job. Share this post Link to post Share on other sites
Shynon 7,435 #4 Posted November 16, 2015 Just because it is knocking doesn't mean it needs a crank, but if it measures bad you can get good used ones. I have gotten a couple of good used cranks from sellers like "Joe's" on for a lot less than having one turned. As long as you are dealing with a vendor that has a good reputation you will be OK. Some times the crank will have a deposit of aluminum from the rod on it, if that is the case a little muriatic acid will clean it up for you.Engine rebuild kits on from bakt4kids are quite good and run $90 to $150 depending on how many components you need. Knocking can be caused by a stretched rod cap from over revving engine ( over 3600rpm) Prondzy and I have built a dozen k series kohlers with after market parts from as Brian Millers web site states he has built many kohlers from aftermarket parts and noticed no difference, good machining and clean assembly area are the keys to a good long lasting build. Cranks has to be measured and if in specs you are good to go. If you don't have one go to library and check out a kohler manual, or download from or buy one. I use mine all the time, all specs are in the manual. Pull the heads and see if piston has a number on top stating bore. If you have a .030 on top it is already to the max. Then you will need to re sleeve the block. 3 Share this post Link to post Share on other sites
Howie 882 #5 Posted November 16, 2015 Have used quite a few of the aftermarket parts for these engines over the years and they have held up pretty well. Cranks can be turned, .020 undersize aftermarket rods are now available. Kohler never made one of those. A stock rod can be bored for an insert type bearing, my local machine shop used to do that until it sold. Sent two to BrianMiller a couple of years ago to have done, then say a few weeks my supplier had the .020 rods. There is also a .040 over piston and ring now available in the aftermarket stuff.The Mahle style piston from Kohler requires less clearance than the old style also. The shop that I used to use charged around $40 to grind but he retired and they did not replace him.Found another place he charges $50 but is slow. Any used crank will likely have some wear.David Share this post Link to post Share on other sites
tractorhogg 611 #6 Posted November 16, 2015 Just because it is knocking doesn't mean it needs a crank, but if it measures bad you can get good used ones. I have gotten a couple of good used cranks from sellers like "Joe's" on for a lot less than having one turned. As long as you are dealing with a vendor that has a good reputation you will be OK. Some times the crank will have a deposit of aluminum from the rod on it, if that is the case a little muriatic acid will clean it up for you.Engine rebuild kits on from bakt4kids are quite good and run $90 to $150 depending on how many components you need. Knocking can be caused by a stretched rod cap from over revving engine ( over 3600rpm) Prondzy and I have built a dozen k series kohlers with after market parts from as Brian Millers web site states he has built many kohlers from aftermarket parts and noticed no difference, good machining and clean assembly area are the keys to a good long lasting build. Cranks has to be measured and if in specs you are good to go. If you don't have one go to library and check out a kohler manual, or download from or buy one. I use mine all the time, all specs are in the manual. Pull the heads and see if piston has a number on top stating bore. If you have a .030 on top it is already to the max. Then you will need to re sleeve the block. I've heard from many the after market parts aren't as important as the workmanship, but as a personal preference I would want kohler parts even knowing they might not be any different. The real TP kohler manuals can be found all over for free, but again it depends on you and your shops level of competency and knowledge about rebuilding engines. I studied field surgery in the military, but I don't do it for myself (not often) or others. Share this post Link to post Share on other sites
prondzy 3,867 #7 Posted November 27, 2015 On 11/15/2015, 8:45:38, tractorhogg said: I've heard from many the after market parts aren't as important as the workmanship, but as a personal preference I would want kohler parts even knowing they might not be any different. The real TP kohler manuals can be found all over for free, but again it depends on you and your shops level of competency and knowledge about rebuilding engines. I studied field surgery in the military, but I don't do it for myself (not often) or others. If your comfortable building the engine yourself I wouldn't hesitate to use aftermarket pistons/rings, rods. If your not comfortable building engines by all means use a local shop or a members of this site to walk you through the process with a couple cheap specialty tools. But I wouldn't expect Brian miller to build an engine with genuine kohler parts for $500-$600 (especially if you read his website) when a nos kohler piston is selling for $100-$200, connecting rods for $100,machining costs around $100. Just my , and good luck on your descision! 2 Share this post Link to post Share on other sites
tractorhogg 611 #8 Posted November 27, 2015 3 hours ago, prondzy said: If your comfortable building the engine yourself I wouldn't hesitate to use aftermarket pistons/rings, rods. If your not comfortable building engines by all means use a local shop or a members of this site to walk you through the process with a couple cheap specialty tools. But I wouldn't expect Brian miller to build an engine with genuine kohler parts for $500-$600 (especially if you read his website) when a nos kohler piston is selling for $100-$200, connecting rods for $100,machining costs around $100. Just my , and good luck on your descision! No, I doubt Brian Millers price is for real Kohler parts, but the price an individual pays for kohler parts is 40-60 percent more than kohler sells to guys like him. I get a 40 percent off list price from my supplier on parts and I'm a small time buyer, my cost is less than 30.00 on just an after market piston. Share this post Link to post Share on other sites
Shynon 7,435 #9 Posted November 27, 2015 47 minutes ago, tractorhogg said: my cost is less than 30.00 on just an after market piston On 11/15/2015 8:45:38, tractorhogg said: personal preference I would want kohler parts Share this post Link to post Share on other sites
tractorhogg 611 #10 Posted November 27, 2015 1 hour ago, Shynon said: Your keyboard must be broken Share this post Link to post Share on other sites
