rustyoldjunk 127 #1 Posted November 7, 2008 the 520 i just drug in seems to have some wiring issues.it will turn over like it nots firing,then backfire occasionaly thru the carb,then start up and run fine a while then just shut off like you shut off the key,sometimes it dont want to start at all.i pulled the wires behind the dash around some looking for possible causes now it wont turn over at all,i left it at that as i had to leave for work.also i noticed the seat switch light didnt always come on when i turned the key but it did a couple times.i will look at it more tomorrow,may try bypassing the seat switch first thing.i have heard the 520's are somewhat prone to electrical issues but not having much experience with newer stuff (i normaly prefer 60's-70's tractors).im asking the newer tractor gurus what are some of the common electrical problems,causes,and cures of these onan powered wheel horses. Share this post Link to post Share on other sites
Sparky-(Admin) 19,563 #2 Posted November 8, 2008 Sure hope it aint the valve seat . Sorry I cant help ya on this one. Mike......... Share this post Link to post Share on other sites
BPjunk 184 #3 Posted November 8, 2008 OK lets think a minute .......... The first thing I would do is get a "In Line Spark Checker" and put on the #1 cylinder (it is eayser to see from the driver seat), now turn the key to START and see if you get the light bulb to glow. This will determain if the problem is carburetion or ignition. Now you say the engine will cut right off for no reason and the spark checker will again see if there is ignition. Chances are the most of the electrical connections are either dirty, corroded or loose, you should check over all connections from the battery to the fuse box to the key switch and every safety switch. Wild Bill in Richmond, Va. Share this post Link to post Share on other sites
Raider12 13 #4 Posted November 8, 2008 i noticed the seat switch light didnt always come on when i turned the key but it did a couple times. I think I might try and bypass the seat switch to eliminate it being a problem. I may be wrong, but I think there is also a PTO switch that may keep it from starting if it thinks the PTO is ingaged at start up. Someone else would have to confirm this though. It been my experince that most electrical issues are due to bad grounds or corrosion in any connection. :hide: Share this post Link to post Share on other sites
