Keith 21 #1 Posted December 9, 2018 520H runs smooth for a few minutes then dies like switch was cut off. Starts again and will run for a minute or two then dies again. The previous owner said he replaced an ignition module last summer, for this reason. Apparently that wasn't the cause of the stalling. Are there electrical diagnosis procedures for this engine? Share this post Link to post Share on other sites
lynnmor 6,779 #2 Posted December 10, 2018 Here is the engine manual. It does sound like the ignition module. Find the demystification guide on this site as well, perhaps you have safety or ignition switch problems. Check fuel delivery as well, perhaps the gas tank vent is plugged. 1 Share this post Link to post Share on other sites
Keith 21 #3 Posted December 12, 2018 It began to stall a few minutes ago. I adjusted the choke and it smoothed out but could not get any power - no RPMs. There must be a carb issue. Are new carbs available? Where is the best place to get a carb kit ? Share this post Link to post Share on other sites
Keith 21 #4 Posted December 12, 2018 I have a 4WD Kubota for pulling. The Speedex is interesting looking but I wanted a use for it. Nobody seems to want garden tractors unless they come with attachments like blades or tillers. I read that the Speedex attachments are difficult to install, but I won't have any extras. I have a Ford LGT 125 (Jake), the 520H, C160, C120, Power King 1614, Cub Cadet 782, 3 Sears Suburbans and the Kubota B6100. The Kubota is much better than any of those for actual work and it only weighs 1,050 pounds. The 4WD makes all the difference. 1 Share this post Link to post Share on other sites
lynnmor 6,779 #5 Posted December 13, 2018 Rarely does a carburetor need replaced. Try cleaning it out thoroughly, you may be able to save the old gaskets and not buy any parts. Carburetors and kits are available from vendors on this site, other websites and the big online auction site. Share this post Link to post Share on other sites
Keith 21 #6 Posted December 13, 2018 The hour meter says 1730. The Onan will fire right up. But it loses power after a few minutes. I ordered a head gasket set and will decarbonize and inspect the cylinder head. First, I'll check the compression. I was planning on rebuilding it, but the motor might already have been rebuilt. Share this post Link to post Share on other sites
Keith 21 #7 Posted December 13, 2018 I left it idling in a flat spot and it didn't stop running. When I attempted to back up a 30 degree slope it does. I left is roll down the hill and it started right up. It idled for 10 minutes with no stalling. Could there be a fuel issue with slopes? Share this post Link to post Share on other sites
WVHillbilly520H 10,369 #8 Posted December 13, 2018 Yes the in tank filter that is on the fuel petcock(shut off valve) could have become corroded from ethanol, the fuel filter could need changing or the pump itself could be weak or even the vacuum hose operating could be loose or a hole it behind the flywheel shroud ,those pumps are cheap enough here...https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F282742282069...the rubber fuel lines themselves could be collapsing on the inside from ethanol deterioration lots of things to consider especially with 1700 hrs on it. 1 Share this post Link to post Share on other sites
Keith 21 #9 Posted December 16, 2018 I ordered a new fuel pump. Can an upper cylinder soak be performed on the Onan motor? Share this post Link to post Share on other sites