Jess 29 #1 Posted September 7, 2014 Hi , I am a new member and have owned a wheel horse mowers since 1986. I now have 3 of them. I started having a problem with my 518H with a 18HP onan motor . P218G Spec #1710539B SR# H1873262205 It began to just stop running, Then it would start and run again for a while and then stop. It finally quit all together ? I bought this machine new around 1986 . I have always maintained it and have had no problems with it at all till this. I read some where that the best place to start is with the condenser so I ordered a new one and it still did nothing. It has always cranked and gets gas to the carb so the fuel is no issue. I thought maybe the ignition coil might be bad. This is where it gets interesting. I also have another wheel horse 520H Power Plus P220G motor Spec 1710955C SR# C or G 893580749 or 8 I cant make out the first letter or last number well. My 520 was running at the time with no issues. So I looked at the coils and they were a match so I got the bright idea to take the coil out of the 518 and swap them out before just running out and buying a new one as you all know how expensive these parts are. I put the 518 coil in the 520 and the 520 in the 518 . I first tried to start the 520 which was the running machine and it just cranked and would not start. So I figured (GREAT) I have a bad coil? But when I tried to start the 518 it still would not start? ??? So I put the coils back in the machines where they belonged. Now my 520 will not start either?????? So as I'm getting older and cant see well I juts by chance switched them again, after marking them this time. And I still have no spark to either machines? So I figured I would start to try and just get my 518H running. Now I pulled the flywheel off and took the ignition coil mounted behind it as I have read somewhere that this might be the cause????? I am now at a stand still. with both of the ing coils out the ones that the spark plugs go to and the 518 with the flywheel off and don't know where to go from here. Is there some kind of way to test all this stuff and see if its bad or not? I called the only wheel horse dealer in my area which is 60mils one way and they said there is no way to test these parts and just start replacing them? The one coil with the sparkplug wires running to it is $175 bucks and the coil I think its called a pickup coil behind the flywheel is $170 And now I read somewhere that it could be the regulator? I am retired and don't have the kind of bucks to hit and miss all of this. Any help would be gratefully appreciated Jess Share this post Link to post Share on other sites
Theroundhousernr 589 #2 Posted September 7, 2014 In the electrical section is a pinned post all about this. Make sure you have twelve volts at the coil and make sure the condensor is on the positive side of the coil. Read that post in the top of the electrical section and report back after testing. Good luck Check the pinned thread 1 Share this post Link to post Share on other sites
Theroundhousernr 589 #3 Posted September 7, 2014 Also the part behind the flywheel is the ignition module. Dont hook this up backwards. I believe this is pretty well impossible because the posts on the coil are different sizes but just thought I would mention it. 1 Share this post Link to post Share on other sites
Martin 2,130 #4 Posted September 7, 2014 heres the link to the thread mentioned above. Share this post Link to post Share on other sites
Theroundhousernr 589 #5 Posted September 7, 2014 Thanks for the link Martin. I'm on my phone and didn't want to even attempt it. Share this post Link to post Share on other sites
Molon_Labe 731 #6 Posted September 7, 2014 Jess and there's plenty of knowledge here to get you going again!!!! Share this post Link to post Share on other sites
Jess 29 #7 Posted September 7, 2014 Also the part behind the flywheel is the ignition module. Dont hook this up backwards. I believe this is pretty well impossible because the posts on the coil are different sizes but just thought I would mention it. Share this post Link to post Share on other sites
km3h 543 #8 Posted September 7, 2014 Before tearing an engine apart, it is always best to run some basic tests. If you are getting fuel to the Carburetor, and you have air, the first thing to check is voltage. Using a volt meter check the voltage to the positive side of the coil. If you do not see 12 volts there you can run a jumper wire from the positive side of the battery directly to the coil and then turn the key to start and the engine should fire. This tells you that the circuit between the key switch and the coil is broken somewhere. Most likely a safety switch. Please make sure that you do not have the PTO engaged. Happens to all of us at one time or another. Also make sure you have the parking break applied. 1 Share this post Link to post Share on other sites
Jess 29 #9 Posted September 7, 2014 Thank you, When I first started this mess, the only wire that ran to the neg side of the coil was the condenser on both the 518 & the 520 ? Nothing else was on that post. On the postive post was 3 wires 2 from the inginition moudle the red and the blak and one other blk wire? I wrote this down as I was taking them off. I looked at the 2 wires from the ing moudle and I see one red and one blk and wondered about this myself? And your right the red wire will not go on the neg post but the blk does fit on the positive post? This is the first time my 518 has been apart since I bught it new in 1986 as for the 520 I bought this second hand a few years back and has always ran with no problems. And has not been worked on since I touched it? Thank you again for your help Jess Share this post Link to post Share on other sites
Jess 29 #10 Posted September 7, 2014 Before tearing an engine apart, it is always best to run some basic tests. If you are getting fuel to the Carburetor, and you have air, the first thing to check is voltage. Using a volt meter check the voltage to the positive side of the coil. If you do not see 12 volts there you can run a jumper wire from the positive side of the battery directly to the coil and then turn the key to start and the engine should fire. This tells you that the circuit between the key switch and the coil is broken somewhere. Most likely a safety switch. Please make sure that you do not have the PTO engaged. Happens to all of us at one time or another. Also make sure you have the parking break applied. So I should put the coil back in the 520 as this one I have not taken the flywheel off yet? And try some of these test? Both of my machines have always cranked and have gass flow. I think if I had an open in a saftey that they would not crank? Aslo did you see when I just posted about the location of the wires? Thank you for your help and time Share this post Link to post Share on other sites
Theroundhousernr 589 #11 Posted September 7, 2014 Test your coils with your meter now that they are out first. Put back in the 520. Positive post on coil should be condenser, yellow wire from harness and positive of ignition module. Only thing on negative post would be the negative of ignition module. Then start testing things like safety switches, power to coil and module with procedures from Martin's post. I'm on my phone or I could go in more details. Share this post Link to post Share on other sites
Jess 29 #12 Posted September 7, 2014 Test your coils with your meter now that they are out first. Put back in the 520. Positive post on coil should be condenser, yellow wire from harness and positive of ignition module. Only thing on negative post would be the negative of ignition module. Then start testing things like safety switches, power to coil and module with procedures from Martin's post. I'm on my phone or I could go in more details. I jsust checked both of my coils as I have them in hand and they check out good acording to the poast from Martin. I dont want to act like a fool but like I said the only wire on my neg coil post was the condenser? If I wire it the way you are telling me may I do some more damage? But at this point nether of the machines are running any way ? Thank you for your help!!!!!!!! Share this post Link to post Share on other sites
Theroundhousernr 589 #13 Posted September 7, 2014 (edited) The way I told you is the correct way right from the book. Onan wires condenser to positive output. Edited September 7, 2014 by Theroundhousernr Share this post Link to post Share on other sites
Jess 29 #14 Posted September 7, 2014 (edited) I jsust checked both of my coils as I have them in hand and they check out good acording to the poast from Martin. I dont want to act like a fool but like I said the only wire on my neg coil post was the condenser? If I wire it the way you are telling me may I do some more damage? But at this point nether of the machines are running any way ? Thank you for your help!!!!!!!! The way I told you is the correct way right from the book Thank You Thank You, I do have the one ing module from my 518 in hand and when I put my meter on it I have no reading like it is open and I just went out and read the module on my 520 and it is reading almost 11 OHMS ? could this be my problem from my 518 and maybe I did screw up getting the wirs right on my machines and if I put the coil back in the 520 it may run again Edited September 7, 2014 by Jess Share this post Link to post Share on other sites
km3h 543 #15 Posted September 7, 2014 The first thing you should always do before disassembly of anything, especially wiring is take some photos. It very easy to forget which wire goes to which post. Share this post Link to post Share on other sites
Jess 29 #16 Posted September 7, 2014 (edited) The first thing you should always do before disassembly of anything, especially wiring is take some photos. It very easy to forget which wire goes to which post. At my age its easy to foget just about any thing ! Now for my 518 ? do you think the ing coil is the culprit ? I am sorry to be so bothersome while your on the phone but its hard to get any help here in the Ozarks with this kind of stuff! Thank you forn your time Edited September 8, 2014 by Jess Share this post Link to post Share on other sites
Theroundhousernr 589 #17 Posted September 7, 2014 (edited) I meant I'm on red square on my phone and its a real bummer typing. I'll chime in later if someone does not. I would bet ignition module if you put twelve volts to the coil and still no spark Edited September 7, 2014 by Theroundhousernr Share this post Link to post Share on other sites
Geno 1,928 #18 Posted September 7, 2014 Hi Jess and Share this post Link to post Share on other sites
km3h 543 #19 Posted September 7, 2014 I meant I'm on red square on my phone and its a real bummer typing. I'll chime in later if someone does not. I would bet ignition module if you put twelve volts to the coil and still no spark Join the age club. I am 78 and know what it is to forget easily. I also hate to communicate on my cell phone. I do like it for the convenience of taking photos. It is fast and easy to use and always on hand. I hope you have stopped jumping from tractor to tractor. The best thing you can do is concentrate on getting one at a time running. Since the 520 was running when you started it would seem that it would be the easiest to do first. Here is a page showing the starting circuit of the 520-H Sorry it is not larger but it is the best I could do. If you can, go to Toro and download their demystification guide. you will need the model and serial number from one of your tractors. It is a great PDF file and covers a lot of tractors. Makes for an easier diagnoses. Share this post Link to post Share on other sites
Jess 29 #20 Posted September 8, 2014 (edited) I meant I'm on red square on my phone and its a real bummer typing. I'll chime in later if someone does not. I would bet ignition module if you put twelve volts to the coil and still no spark Well I just put the coil back in my 520 and wired it up the way you told me and what do you know I now have only on dead horse!! I was driving myself nuts over this ! Thank you all for your input . I think befor I put the flywheel back on my 518 I need to replace the ing moduel as I said when I put my meter on it it read open and on the 520 I had almost 11 OHMS . I hate to put it all back together then take it apart again. The 518 had voltage to the coil and had fuel but no spark. It cranked good also. Would you know what the # for the ing module would be as the one I ttok out had no numbers on it at all? Do they make something generic for it or do I have to go back to a dealer? Thank you for your time and help Jess Edited September 8, 2014 by Jess Share this post Link to post Share on other sites
ol550 830 #21 Posted September 8, 2014 There is a member here that has a ignition module on ebay right now. Share this post Link to post Share on other sites
km3h 543 #22 Posted September 8, 2014 Here is the page you want I think. Not sure what you mean by the ring module but this should have all the parts you are looking for, If not, let me know and I will try to find it for you. If you are talking about part number 3, that is the ignition rotor and the part number is 166-0767 Share this post Link to post Share on other sites
km3h 543 #23 Posted September 8, 2014 By the way, if your coil is bad, you can use the coil from a Harley Motorcycle. They only cost about $30.00 and will do the same job as the Onan. I use one on my Kohler KT17 twin and the motor does not know the difference. Share this post Link to post Share on other sites
Jess 29 #24 Posted September 8, 2014 (edited) There is a member here that has a ignition module on ebay right now. I looked but did not find it? Thank you Edited September 8, 2014 by Jess Share this post Link to post Share on other sites
Jess 29 #25 Posted September 8, 2014 Here is the page you want I think. Not sure what you mean by the ring module but this should have all the parts you are looking for, If not, let me know and I will try to find it for you. If you are talking about part number 3, that is the ignition rotor and the part number is 166-0767 Onan_P216G_P218G_P220G_Parts_Catalog_19981000 18.jpg No its not #3 I amd looking at the part below #3 it is the inginition module behind the flywheel. The Harley coil you mentioned is it the one with the spark plug wires going to it? Thank you Share this post Link to post Share on other sites
