grinchsr 594 #1 Posted February 27, 2015 Just picked up a Model #73542 but it has a CH18 motor. Isn't it supposed to be a 20 HP motor? Did it have a transplant? These 5XI machines are new to me. Share this post Link to post Share on other sites
Rick_in_CT 156 #2 Posted February 27, 2015 The 73542 does show up as a 520xi. A CH18 would be 18hp, not what should be in a 520xi. If you provide the full information from the motor label I can give you more information. Need the full model #, spec. #, and Serial #. Rick Share this post Link to post Share on other sites
grinchsr 594 #3 Posted February 27, 2015 Hi Rick here is the info CH18 SPEC-24 782 15 SERIAL- 3428607761 THANKS for getting back to me Share this post Link to post Share on other sites
Rick_in_CT 156 #4 Posted February 28, 2015 The "Spec" number you provided does not come up in the Kohler Command Service Manual. I did a search on the number and I find the following as available from Kohler: 24 782 15 CH18 MINIBLOCK (KM) KOH2478215 If you go to jackssmallengines.com and enter part number 2478215 this miniblock will come up. This looks like a replacement block spec number, less heads, carb, etc.. The serial number starting with 34 looks to represent year 2004. It shows that this part number is for the CH18. I did find some miniblocks that showed they were used for CH18/20, but this number shows up as just CH18 as far as I can see. Pretty perplexing. Rick Share this post Link to post Share on other sites
Rick_in_CT 156 #5 Posted February 28, 2015 If you look at the chart below from the Command engine owners manual, the CH740 is the 18HP and the CH745 is the 20HP. The bore, stroke, and displacement are all the same. I'm wondering then if the short block is the same for the 18 and 20HP. If this is the case, then how does Kohler get the extra 2hp from the engine? Can someone shed some light on this. Rick Model: ............................................................. CH730 .............. CH26/CH735 ....... CH740 ................ CH745 .................... CH750 Bore: ............................................mm (in.) ... 83 (3.27) ........... 83 (3.27) ............... 83 (3.27) ............. 83 (3.27) ................. 83 (3.27) Stroke: .........................................mm (in.) ... 67 (2.64) ........... 67 (2.64) ............... 67 (2.64) ............. 67 (2.64) ................. 69 (2.72) Displacement: ........................... cm3 (in3) ... 725 (44) ............ 725 (44) ................ 725 (44) .............. 725 (44) .................. 747 (45.6) Power (@ 3600 RPM): ................ kW (HP) ... 18.6 (25*) .......... 19.4 (26*) .............. 20.1 (27*) ............ 20.9 (28*) ................ 22.4 (30*) Compression Ratio: ..................................... 9:1 ..................... 9:1 ......................... 9:1 ....................... 9:1 ........................... 9.4:1 Weight: ........................................... kg (lb.) ... 43 (94) .............. 43 (94) .................. 43 (94) ................ 43 (94) .................... 47 (105) Share this post Link to post Share on other sites
Rick_in_CT 156 #6 Posted February 28, 2015 If the previous owner/owners replaced the block with the miniblock 2478215, it comes less the crankshaft. They may have then re-used the crank, heads, carb, etc. I do see that the 18hp heads have a different part number than the 20hp heads. If they purchased the miniblock for the CH18, then transferred the heads, crank, carb, etc. from the CH20, would you end up with a 20hp engine?? Share this post Link to post Share on other sites
boovuc 1,090 #7 Posted February 28, 2015 I think it was mid-2007 that the major small engine manufacturers got drilled in court for making exorbitant HP rankings of their motors. If the heads are different between the Ch740 and the Ch745, that could be where Kohler was stating the 2 extra HP is coming from since we are talking about an engine made in or around 2004. Probably not a true 20 horse motor but who really knows what is true anymore other than the old single Kohlers, Briggs and Tecky's. Is my Onan P220 truly 4 more horsepower than a 16 horse Kohler K341? I doubt it! Rick. I think you are correct in your thinking. Thanks for digging into this! It's doubtful but does anyone have pics of the Ch740 and Ch745 heads? I'll bet they are different! Share this post Link to post Share on other sites
grinchsr 594 #8 Posted February 28, 2015 THANKS for the answers. The way it looks someone put a short block in this thing Share this post Link to post Share on other sites
Rick_in_CT 156 #9 Posted February 28, 2015 Yeah, at first glance it didn't sound right, but after looking closer it may be all good. Do you know what year the tractor is? If you don't, post the serial number from under the seat and I can tell you the year. You might have actually gained a little if the engine is now newer than the tractor. You might just consider that it has been "refreshed". So, where are the pics??? Did you get any attachments? The 5xi is a great tractor, very reliable. Rick Share this post Link to post Share on other sites
shallowwatersailor 3,213 #10 Posted February 28, 2015 I think it was mid-2007 that the major small engine manufacturers got drilled in court for making exorbitant HP rankings of their motors. If the heads are different between the Ch740 and the Ch745, that could be where Kohler was stating the 2 extra HP is coming from since we are talking about an engine made in or around 2004. Probably not a true 20 horse motor but who really knows what is true anymore other than the old single Kohlers, Briggs and Tecky's. Is my Onan P220 truly 4 more horsepower than a 16 horse Kohler K341? I doubt it! Rick. I think you are correct in your thinking. Thanks for digging into this! It's doubtful but does anyone have pics of the Ch740 and Ch745 heads? I'll bet they are different! Just like, Boo, mentioned. I have checked the specs on both the 518xi and 520xi. The engines are identical. It may be a case, as RMCIII mentioned in a post one time, that the carb and /or governor spring being placed in a different hole to gain additional hp. The big difference (and it sounds like it is a 520xi) is the 1" larger and thicker steering wheel, tail lights, and if you can use it, cruise control. The 522xi CH22 engine was different. Share this post Link to post Share on other sites
grinchsr 594 #11 Posted February 28, 2015 Hi Rick No pics yet because it needs a serious cleaning. All I got with it was a 48 inch SD deck but that is all I need. I have other machines for snow removal and tilling. I am not flipping this machine but I would think the value dropped because it should have a 20 horse but it is now only 18. Do you happen to have a set of 12 inch wheel weights? RAY Share this post Link to post Share on other sites
shallowwatersailor 3,213 #12 Posted February 28, 2015 Hi Rick No pics yet because it needs a serious cleaning. All I got with it was a 48 inch SD deck but that is all I need. I have other machines for snow removal and tilling. I am not flipping this machine but I would think the value dropped because it should have a 20 horse but it is now only 18. Do you happen to have a set of 12 inch wheel weights? RAY That could be the reason it has a possibly a short-block. If grass clippings are bad around the frame, the engine heads are probably just as bad. You probably need to get behind the engine shroud to clean as well. Great machine though! Share this post Link to post Share on other sites
