520 Won' Start

[WHX?? 48,834]

Not so fast Madge ...I said I got it running I didn't say it was fixed. Appears ther are more mysteries to be solved more gremlins to chase.

[WVHillbilly520H 10,373]

38 minutes ago, WHX24 said:

Not so fast Madge ...I said I got it running I didn't say it was fixed. Appears ther are more mysteries to be solved more gremlins to chase.

Smoke coming out of the module , I'm not saying its wrong but the fuel filter was always after the fuel pump on mine since new, I believe it's easier on that pump to "push" the fuel through the filter than "pull" it ... 

[WHX?? 48,834]

Actually  that's where it was Jeff... Prolly the orginal filter ('91) now that you say that. I just went on the premise of trying to keep crap out of the pump. I replaced that line and moved the filter behind the pump with a check  valve just behind it. 

BTW  I popped the top off the carb and cleaned the bowl best I could on tractor. Kinda a  to do with the blower on since the hood can't open all the way. Pump moved fuel fer sure. Clear view filter and  cranked plugs out to purge. 

 Not a fuel issue definitely electrical. Most likely not the module either. Sigh of relief here I may not have to pull the tins and flywheel. 

 

Edited December 31, 2020 by WHX24

[Achto 27,622]

Just a thought here but.... Could it possibly be the nut behind the wheel ????

[WHX?? 48,834]

Distinct possibility ther Dan... 

So the correct answer to the multiple guess is I don't have a clue. Plugs were showing no sign of spark again so went back to the manual and jumpered  bat right to positive on the coil and she fired right off once she cleared all the salts I been  dumping down her throat. Previously had bat voltage to the coil in run. 

Ran like a champ and quickly removed the bat jumper and she continued to stoke with no issue. Warmed up with no issues. Shut her down and she cranked right back up. I says gotta  be in a kill relay or the oil pressure cutout??? Maybe ig switch??  So left her set abit and now she won't even fire with a jumper . 

Ripped my hair out and half the beard and said to heck with it I'm boarding. 

 

[WVHillbilly520H 10,373]

35 minutes ago, WHX24 said:

Distinct possibility ther Dan... 

So the correct answer to the multiple guess is I don't have a clue. Plugs were showing no sign of spark again so went back to the manual and jumpered  bat right to positive on the coil and she fired right off once she cleared all the salts I been  dumping down her throat. Previously had bat voltage to the coil in run. 

Ran like a champ and quickly removed the bat jumper and she continued to stoke with no issue. Warmed up with no issues. Shut her down and she cranked right back up. I says gotta  be in a kill relay or the oil pressure cutout??? Maybe ig switch??  So left her set abit and now she won't even fire with a jumper . 

Ripped my hair out and half the beard and said to heck with it I'm boarding. 

 

Jim, the low hour '95 I wrangled a few years back, the neutral safety switch under the steering wheel had the activator lever MIA and PO had jumpered it to get it to run start and run, took me 2 weeks to figure it out (even with the wiring diagrams and the magic test wand,) also it and the '94 I sold,  the PTO switch under the fuse box both were severely out of adjustment and would cause an intermittent start/no start...start...sostart...start...something to check out, it could be a sticking/rusty relay under the battery, and yes the blower chute and sway bar make it a PITA to get the hood up to work on the top of the engine.

[WHX?? 48,834]

I put Matt's pedal kit on this one so motion lever is gone. Pretty sure when I installed it I just tie wrapped that switch closed. Seat switch is also bypassed but think the PTO one is still active. Will check those out. I had thought if those switches aren't made she won't even crank over ??? More wiring diagram study is in order. Also going to focus on the kill relay that feeds the coil. Possible it is letting voltage but not amps thru? I can hear it click when key to run but that doesn't mean the contacts aren't making? 

Edited December 31, 2020 by WHX24

[Chestnut 315]

I also got my 520-H snowblower out this fall and ran into a few gremlins. Replaced the regulator because it wasn't charging. Had snow Dec. 6 and took it out to clear. Ran OK for about 20 minutes but then wouldn't run under load. Started fine, could even run the RPN's all the way up without a load, but as soon as I tried to start the snowblower or move it faster than a crawl the engine crapped out. Fuel filter looked a little empty and I never have a lot of fuel in the tank, so I added some. No change. Got it back near the shed but wouldn't even go up the little rise to the shed door and inside. Pulled the top of the carb to check for crud and didn't really find any. Tried confirming fuel flow by cranking it over with the float and needle out. Got fuel. Back together, same problem. Repeated the process once or twice more, same results. Then I realized every time I pulled the carb top the float bowl was empty and the floats were sitting on the bottom of the bowl. Decided to order a fuel pump. Installed the pump and a primer bulb. Couple of squeezes on the bulb and it barked right to life, ran fine. I think the old fuel pump was working, just not well enough.

While I was feeling lucky I decided to see whether the other 520-H FEL would start. It's always been a bit reluctant even after I cleaned the carb. All summer it started, but needed full choke and cranked until I saw a bit of black smoke from the exhaust, then sputtered to life. In the December cold it didn't sputter. The old battery was winding down so I gave up and put the charger on. 20 or 30 minutes later, tried again and it immediately sputtered. Caught about the third time and ran fine with a little warmup. No more than 20 hours on new plugs and wires, but not sure what brand plug. Probably put some new NGK's in for spring and keep trying to resolve the hard start. Sure would like it to light up like the other one. 

I always run them dry before storage and restart with some ethanol-free from a can with a bit of Stabil.

To answer the comment above, mine don't crank at all if the seat, hydro position, or PTO are in the wrong position. I think I even had an indicator light telling me about a safety switch being off.

[WVHillbilly520H 10,373]

6 hours ago, Chestnut said:

 

To answer the comment above, mine don't crank at all if the seat, hydro position, or PTO are in the wrong position. I think I even had an indicator light telling me about a safety switch being off.

With the PTO microswitch, the funny thing was one time it would crank just fine the next time NO warning light but wouldn't crank until the engagement lever was wiggled, as far the neutral switch the PO had bypassed with a jumper wire and I wanted it back to original without the extra wires, even while trying to pinpoint the cause with a test light i would accidentally hold the plunger down without realizing the actuator was missing until I pulled the dash panel on my Anniversary 520, its funny how sometimes something so tiny yet in plain site can cause your brain to ache... And I'll be the first to admit it.

[gwest_ca-(File Mod) 11,057]

 

[WHX?? 48,834]

So Dan stops over to swap out some tires & rims and it starts right up every time. Out to the shop to stoke the stove for the night and just for grins try it again... yep no start.  Gotta be a loose wire or relay... back at it today.

[AMC RULES 37,132]

Take it to Dan!

[WVHillbilly520H 10,373]

39 minutes ago, WHX24 said:

So Dan stops over to swap out some tires & rims and it starts right up every time. Out to the shop to stoke the stove for the night and just for grins try it again... yep no start.  Gotta be a loose wire or relay... back at it today.

Now you see what I be spraying.  

[peter lena 8,647]

was  this 520 previously running ? sounds like a corroded or  frayed wire connection . I agree with the loose or corroded wire or relay ,  I WOULD JUST JUMP THAT TO SEE IF IT WORKS ,  not familiar with 520 ,s   but to listen to the typical problems , sounds like a VERY THOROUGH , wire system check  would really help out. you have to get fed up enough with the problem , to correct it. when it comes to w/h wiring issues , I typically only use the routing as a guide , (  and improve on that ) all connectors are much better , dielectric grease enhanced , and added grounds , with serrated washers . constant regular problems , made me go back to a fresh start wiring set up , all 3 of my horses , start up instantly , none of them are onan.s  or later series. you have to want to change this , pete 

[WHX?? 48,834]

Think I may have found the culprit....

 

This is why a guy needs parts motors! Dug this one out of the snow bank hopefully got a good one. 

Edited January 2, 2021 by WHX24

[AMC RULES 37,132]

Haven't I read there is a cheap Harley part that will fix that problem?

[WHX?? 48,834]

Yep all fixed ....bizarre thing is this coil passes resistance tests with flying colors. Probably should have spied that crack from the topside.  Looking down in the coil caviity says this girl needs a good cleaning under the tins. 

Yes Madge a 3 ohm coil off older Harleys will work fine would have to get creative on mounting tho. If I am not mistaking ther was a replacement kit  to move the coil out of the hot zone. Maybe @onanparts.com can chime in on this. I know one of my later nineties 520's has the coil mounted differently. 

 

The parts motor was always supposed to come in the shop for disassembly anyway and see why she fouled plugs and burned oil. @Achto  suggested maybe just a ring job would save it for a complete spare drop in replacement motor.