murph 5 #1 Posted October 7, 2017 have 740 hours on engine smokes out about 1/2 quart on 45 min mowing.Any recommendations on were to start on rebuild or just go for total rebuild / valve job .If total rebuild any things or parts I should make sure gets used and done,thanks gavin ENGINE #'S m148 / 601559 / ser #2228110723 also any shops in the hebron ct area Share this post Link to post Share on other sites
953 nut 51,018 #2 Posted October 7, 2017 With heavy oil consumption like that you are probably looking at a total rebuild including boring the cylinder and an oversize piston. Pick out a shop you are comfortable with and let them measure everything and provide an estimate. You could ask a few equipment rental stores who they use to rebuild their engines to get an idea of who is reliable. 2 Share this post Link to post Share on other sites
wheelhorsebuckeye 16 #3 Posted October 7, 2017 I just fully rebuilt an m14 with 30 years of service this summer. after new gaskets, hardware, machine work and valve job I have 700 bucks in it, but it will last me rest of my life. Share this post Link to post Share on other sites
Fordiesel69 188 #4 Posted October 9, 2017 The M14 is a little different than the M12 that I have more experiance with. It is worth rebuilding if you plan to maintain it. A well cared for Magnum will last 2500 hrs. However kohlers in general do not last long when neglected or if the oil has been let go. You will want to inspect the top of the piston for the word FLY -> If you see this, you have the style "D" mahle forged piston. This is a superior piston if the engine was cared for and maintained. It is not a good piston when it comes time to rebuild as the balancing will be off if using a regular ebay kit or style "A" piston. To make matters worse, these pistons have always been expensive, and are also hard to find. Your options are to find a .010 over or .020 over and have the block bored and to leave the balancing alone. Or to use the ebay kit and have the rotating assy rebalanced. Keep this in mind......the style A piston must be paired with the regular wide wristpin connecting rod. The style D piston must be paired with the narrow strengthened connecting rod. It is not wise to mix the two, or to mill down an aftermarket wide rod to fit. Brian miller does mill them down and has great info on this. This is a very confusing topic because of the two piston types and two rod tyoes. A lot of machine shops lack the kowledge and will tell you to just slap it together. If you do this, the engine will vibrate. I currently operate a M14 that has been rebuilt incorrectly using a .010 Style A piston, with a narrow Style D rod. It does have a little vibration, that my other two original M14;s do not have. I use it so little I am leaving it alone. Style D Mahle Piston: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwj32o_c7uPWAhXszVQKHduIC5YQjRwIBw&url=https%3A%2F%2Fwww.ebay.com%2Fp%2FKohler-Kit-Piston-W-ring-Set-STD-25-874-01-s-Engine-Ko-2587401s%2F1024495203&psig=AOvVaw0KgogjI_zhJH2Jl5FGMtgJ&ust=1507649630605746 Style A Standard Piston: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjTscHs7uPWAhUhxFQKHTD3CmAQjRwIBw&url=http%3A%2F%2Fwww.ebay.ie%2Fsch%2Fsis.html%3F_itemId%3D221458709795%26_nkw%3DNew%2BKohler%2BSTD%2BPiston%2BKit%2B41%2B874%2B06%2BPiston%2BCasting%2B234949%26_mPrRngCbx%3D1&psig=AOvVaw0KgogjI_zhJH2Jl5FGMtgJ&ust=1507649630605746 1 Share this post Link to post Share on other sites
Forest Road 593 #5 Posted October 10, 2017 I've had a k341 sitting on the shelf for 2-3 years. I had it bored .010 and the valves done. I was unaware that it's best to own the piston before you have it machined. My shop assured me a Koehler piston will drop right in. Finding a kohler piston was the hard part. I refused to pay $250-300 for a piston. Just found one on eBay for $100. No doubt they're great long lasting motors. I'd advise breaking it down and sourcing all parts before you spend a dime at a machine shop. A little patience you can find another horse for far less than a OEM Koehler rebuild. 1 Share this post Link to post Share on other sites