Walhonding520 25 #1 Posted July 11, 2017 Just replaced fuel lines and plugs on 520h. Have fuel in line and fuel filter. Turning over fine but won't take off. Anything simple I should be looking at? Didn't even want to fire with a shot of starting fluid. Share this post Link to post Share on other sites
cafoose 3,148 #2 Posted July 11, 2017 Sounds like an ignition problem. Download the manuals here: http://www.wheelhorseforum.com/files/category/14-onan-service-manuals/ Check out these threads: 3 Share this post Link to post Share on other sites
Walhonding520 25 #3 Posted July 11, 2017 Problem continues. Jumped from positive on battery to positive on ignition coil. Fired right up and ran. Mechanic said coil should be fine and needed new ignition switch (key switch). Replaced and same issue still. I've followed as many wires as I can and find no real issues. What's going on? Maybe I am calling the ignition coil the wrong part. I jumped from the battery to the positive on the part that both spark plug wires come from and go to the plugs. I'm looking for any help here. Borrowing the in laws mower every week is getting old. Share this post Link to post Share on other sites
Tim.0 37 #4 Posted July 12, 2017 I you jumped the bat to the coil and engine ran then the coil is good, timing points etc. Now you have to go backwards from the coil to the start switch. Use a multi meter and turn ignition switch on and see if you have voltage at the coil ( positive side bat side of coil)), you should. You could have a loose wire, bad ground, bad fuse. I don't have the wiring schematic in front of me. You could of had a wire which was rubbing on something as example and had damaged the wire. I have also read on this forum there is some different ignition switches for the many wheel horse models thru the years, You have the correct switch? wired correctly? Share this post Link to post Share on other sites
Walhonding520 25 #5 Posted July 12, 2017 It's the switch the shop matched to the one I took in. just another random thought... it started when I jumped from the battery to coil without the seat safety switch pushed down. Without the jumper wire, it turns over fine without starting, but I have tried it with the seat switch both pushed down and nor pushed down. Could the seat switch be bad and causing my problems. I did remove the seat and fenders, disconnecting the seat switch. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,499 #6 Posted July 12, 2017 These pages have one that shows the complete ignition circuit. Garry 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,499 #7 Posted July 12, 2017 If the pto is OFF the seat switch is bypassed. (Not needed to power the coil) If the pto is ON the seat switch must be depressed to power the coil. (Operator falls out of seat with pto ON the engine quits.) Garry 1 Share this post Link to post Share on other sites
Walhonding520 25 #8 Posted July 13, 2017 Thanks everyone. Looks like I'll have to get a tester and start tracing wires... Share this post Link to post Share on other sites
953 nut 51,721 #9 Posted July 13, 2017 The first step in curing electrical problems is to clean and tighten all electrical connections including grounds. 1 Share this post Link to post Share on other sites
Walhonding520 25 #10 Posted July 13, 2017 Another quick question... while looking around I found a very flexible hose attached to a nut with a hole through it that comes out of the air filter box. It is still attached on the air box end but is not on the other. Looks like it has a very small fitting in it. What does this go to? Share this post Link to post Share on other sites
Walhonding520 25 #11 Posted July 13, 2017 Looking at the spark diagram, it goes through the pto switch. Will the engine turn over but just not fire if the pto switch is bad? Share this post Link to post Share on other sites
953 nut 51,721 #12 Posted July 13, 2017 If all the wiring and switches are properly connected and functional the PTO switch will only interrupt the power to your coil If it is turned on and you get out of the seat. The cranking (starter) portion of the switch will prevent the key switch from powering the starter solenoid whether you are in the seat or not. Share this post Link to post Share on other sites
Walhonding520 25 #13 Posted July 15, 2017 The wiring diagram shows a 20A fuse between the battery and the ignition switch. I have found 2 15A fuses on the PTO lever side of the battery and a 30A fuse by the starter. Am I missing a 4th fuse somewhere? Share this post Link to post Share on other sites
953 nut 51,721 #14 Posted July 15, 2017 The twenty amp fuse on the red wire going to the "B" terminal of your ignition switch is the only one that will interrupt the ignition or starter circuits. Share this post Link to post Share on other sites
Walhonding520 25 #15 Posted July 16, 2017 Thank you. Where is the 4th 20A fuse located on the machine? Share this post Link to post Share on other sites
Walhonding520 25 #16 Posted July 23, 2017 Finally had time to work in it. Pulled seat switch out and changed connections and starts right up. I have another issue now but I will start another topic. Thanks for the help Share this post Link to post Share on other sites