jdh 0 #1 Posted November 21, 2019 Hi to all, I'm new here and have a question I have a 1993 520H that I was cutting my yard and it just idled down and wouldn't rev back up when I tried and then just died. Towed it to garage , I have checked the spark, None, put new plugs in still no spark, is there something I'm missing would a coil just quit and idle down? would a ignition module just quit and idle down then die? I did check the oil and was a little low is there a low oil kill switch that might need reset? Thanks Share this post Link to post Share on other sites
lynnmor 7,824 #2 Posted November 21, 2019 There is no low oil switch. The white 9 pin connector near the battery is the first place to check. There is a demystification manual under the manuals section here, download it for help understanding the various circuits. 520s have a number of switches and relays that can be troublesome. The ignition module can quit, download the Onan manual here to troubleshoot the module and coil. Towing a hydro can damage the transmission, hand push only or have it trailered. Report back as needed. The fact that it idled down and not just shut off leads me to think fuel problems, how did you test spark? Share this post Link to post Share on other sites
953 nut 60,070 #3 Posted November 21, 2019 (edited) The problem of idling down and the engine not responding to throttle up could be a fuel problem. If you have been using gas with ethanol it can corrupt the fuel system. Go to this site to find a station near you with ethanol free gas, https://www.pure-gas.org/. Adding a bit of Seafoam to the gas should be helpful. One of the most common reasons for no spark is that in our haste to restart the engine we forget to place the PTO drive in the off position. When the PTO is engaged it will not turn over with the key and there will be no spark without someone in the seat. Here is a screen shot of the ignition components. Check the east stuff first like the electrical connections being tight and the fuse being good. Edited November 21, 2019 by 953 nut Share this post Link to post Share on other sites
jdh 0 #4 Posted November 21, 2019 Hi, I have checked the gas , I have no spark at the plugs, I took them out grounded them to motor and cranked over didn't see any spark. I also jumped from positive to the coil + side and still no spark. Share this post Link to post Share on other sites
lynnmor 7,824 #5 Posted November 21, 2019 1 hour ago, jdh said: Hi, I have checked the gas , I have no spark at the plugs, I took them out grounded them to motor and cranked over didn't see any spark. I also jumped from positive to the coil + side and still no spark. Good chance that the module is bad, do the tests in the Onan manual first. The modules are expensive. Share this post Link to post Share on other sites
953 nut 60,070 #6 Posted November 22, 2019 10 hours ago, jdh said: I also jumped from positive to the coil + side and still no spark. Have you tried removing the wire from the coil that goes to the trigger and replace it with a jumper to ground? Turn on the key and remove the jumper to see if the coil will fire. If you pulse the coil to ground and it is good it should fire. Share this post Link to post Share on other sites
jdh 0 #7 Posted November 25, 2019 I will have to give that a try, I have 3.5 ohms on the coil and believe I have narrowed it down to the ignition module. Share this post Link to post Share on other sites
