Puzzling problems with engines just stopping

[davem1111 2,314]

I posted recently in another thread about having this problem with my 416-H but can't find what I wrote.  Basically, when I'm mowing with the 416-H, it runs great for 10-15 minutes, then it just dies. Sometimes it will start again after a few minutes of sitting, but I think what I determined (at least, one problem) is that the charging system isn't working so the battery goes dead, hence no spark. But it also seemed like the coil was getting very hot,  and it was a "non-standard" coil from what I could tell, so I bought a new coil and regulator. Installed those, tractor runs great, but still dies after mowing for a bit. I made sure the air filter isn't clogged, and fuel flow seems to be steady.  Yesterday I even tried putting a car battery on the left running board and hooking it up in parallel, and maybe that helped some but not enough. Tractor seems to sputter when going from forward to reverse with the PTO engaged, so maybe I have some faulty wiring with one or more safety switches?

 

Anyway, the plot thickens. 

 

While giving the 416-H some "cooling off" time, I started mowing with my GT-1848 (with Honda GX610 engine).  Guess what?   10-15 minutes and it died also. After a few times of that happening, I took it in the garage during a short spurt of running. Recently got some new parts for it so I changed the air filter (it was pretty bad). Due for oil & filter changes for engine and trans but didn't do that yet. Checked wiring, etc., nothing out of place. Battery fine, not run down.  WTH?  It was showing some bubbles in the fuel filter while running, so maybe something going on there? I only had time to run it again for a few minutes but I'm assuming that the problem isn't "solved".

 

It's been very hot, but I haven't had problems like this in the past with it just being hot outside.  I need to take the time to diagnose the charging system on the 416-H but am not anxious to tear into the stator, if that's where the problem is. Will do that if I need to. I'm going to be short on time between now and Labor Day though. Still have about 1/3 of the yard unmowed, and it will be a foot tall before I can get to it assuming I have a tractor running long enough.  My 312-A is in pieces because I finally decided to clean that up and do some repainting.... bad timing.  4 decks, only 2 working right now. Sheesh. I need to retire. 

[ebinmaine 79,964]

Is vapor lock a possibility? 

@squonk mentioned a particular type of fuel filter that's more prone than others.  

[c-series don 12,246]

My first thought was plugged vent in the gas cap, causing vapor lock as Eric said. But with two tractors doing it, now I’m confused 🤔 

[squonk 47,594]

Let's see the fuel filter you're using.

[sqrlgtr 3,547]

EMP

An electromagnetic pulse (EMP) is a short, intense burst of energy. It can damage computers, power lines, and electronic devices. An EMP happens because of natural events like lightning or solar flares, or man-made events like high-altitude nuclear blasts. [1, 2, 3, 4, 5, 6]

I suggest a faraday cage while mowing.

 

[Bill D 3,038]

Any chance a mouse got into the engines.  If they overheat they will shut down.

[lynnmor 8,961]

I guess that the 416H has an Onan engine, if so the most likely cause of shutdown when hot is the ignition module next to the stator.  To test, have a spark plug ready and stick it on one of the spark plug wires and hold the threaded end against a metal engine part while cranking the engine.  Do this as quickly as possible after it shuts down and look for spark.  If none, wait till it cools and test again. Those ignition modules can get temperature sensitive with age.  Maybe your other tractor has the same issue.

[rmaynard 17,487]

Pure coincidence that both did it. My guess is what Don said, clogged gas cap vent. Loosen the cap and see how long it runs. If it works, try the GT as well. Stranger things have been known to happen.

[davem1111 2,314]

5 hours ago, ebinmaine said:

Is vapor lock a possibility? 

@squonk mentioned a particular type of fuel filter that's more prone than others.  

 

Possible.  

 

2 hours ago, Bill D said:

Any chance a mouse got into the engines.  If they overheat they will shut down.

 

On the Onan, more possible - it has more tins covering things.  The Honda engine could have something hiding in there though.

 

2 hours ago, lynnmor said:

I guess that the 416H has an Onan engine, if so the most likely cause of shutdown when hot is the ignition module next to the stator.  To test, have a spark plug ready and stick it on one of the spark plug wires and hold the threaded end against a metal engine part while cranking the engine.  Do this as quickly as possible after it shuts down and look for spark.  If none, wait till it cools and test again. Those ignition modules can get temperature sensitive with age.  Maybe your other tractor has the same issue.

 

Very interesting.  I need to rule out the fuel issues first, which will include draining tank, cleaning screen on outlet valve (or replacing), replacing all fuel line and filter. I have new line and filters already, maybe one tank outlet valve.  The fuel filter on the 416-H is very old and has black paint on it from a P.O. so I can't even see if fuel is moving through it, but.... this tractor ran fine until recently.  But it's been bloody hot lately.

 

As I mentioned, on the 416-H I recently replaced the coil, regulator, and condensor, but didn't know about the ignition module thingy. I bought those as a set, not this one because it includes the module and not the regulator:

 

I can probably do the ignition module test sometime soon, but getting under there to replace the module if it's bad will probably be a fall/winter project.  I don't know if the Honda engine has the equivalent device in a similar location, will have to investigate.

 

 

 

 

I'll see what happens if I can eliminate fuel and possibly mouse-related issues first.  If I need to pull the Honda engine to work on it, I was planning to do that this fall anyway. Whoever did the re-power thought it would be "cool" to mount the engine on a pair of pressure-treated 2x4's, which have since gotten soft and my engine moves when I engage the PTO. Guess I should be grateful it hasn't just fallen out.... 

 

Thanks everyone!

 

 

[ebinmaine 79,964]

1 hour ago, davem1111 said:

pressure-treated 2x4's,

 

Steel would obviously be ideal but even a harder wood species would be a viable quick short term fix. 

[Handy Don 17,113]

51 minutes ago, ebinmaine said:

a harder wood species would be a viable quick short term fix

MANY an early engine used hardwood frame and engine supports. Hickory, rock maple, and white oat are all available without too much effort. 

[lynnmor 8,961]

1 hour ago, davem1111 said:

 

I can probably do the ignition module test sometime soon, but getting under there to replace the module if it's bad will probably be a fall/winter project.  I don't know if the Honda engine has the equivalent device in a similar location, will have to investigate.

 

 

 

Since the problem is very likely heat related you will not have a valid test or fix if you wait.  The repair takes about 2 hours with the shroud being the most trouble.  The flywheel will need a puller, I made a simple plate with 4 holes to match the the threaded holes in the flywheel plus a tapped hole in the center.  I don't like to use the typical steering wheel puller but many do just that.  The flywheel bolt should be loosened about 1-1/2 to 2 turns and your puller will push against it.  When installing the flywheel make sure the surfaces are completely clean and then apply just a hint of rust preventative.  Torque the bolt to 55 lb ft.

[Handy Don 17,113]

2 minutes ago, lynnmor said:

I made a simple plate with 4 holes to match the the threaded holes in the flywheel plus a tapped hole in the center. 

I copied this idea from one of your earlier postings and it worked perfectly. I was almost disappointed that the flywheel came off so easily!

 

After removing the puller and going to remove the center bolt, be SURE you are ready to hold onto the flywheel!  It is heavy and awkward to handle!

[lynnmor 8,961]

1 minute ago, Handy Don said:

I copied this idea from one of your earlier postings and it worked perfectly. I was almost disappointed that the flywheel came off so easily!

 

After removing the puller and going to remove the center bolt, be SURE you are ready to hold onto the flywheel!  It is heavy and awkward to handle!

 

Thank you.

 

I should have mentioned in my post that raising the flywheel side of the tractor a few inches makes the work easier and safer.

[davem1111 2,314]

1 hour ago, ebinmaine said:

 

Steel would obviously be ideal but even a harder wood species would be a viable quick short term fix. 

 

31 minutes ago, Handy Don said:

MANY an early engine used hardwood frame and engine supports. Hickory, rock maple, and white oat are all available without too much effort. 

 

Interesting. Maybe if I didn't already have some square steel tube on hand, I would get some fresh hardwood to replace what is probably just pine.

 

25 minutes ago, lynnmor said:

Since the problem is very likely heat related you will not have a valid test or fix if you wait.  The repair takes about 2 hours with the shroud being the most trouble.  The flywheel will need a puller, I made a simple plate with 4 holes to match the the threaded holes in the flywheel plus a tapped hole in the center.  I don't like to use the typical steering wheel puller but many do just that.  The flywheel bolt should be loosened about 1-1/2 to 2 turns and your puller will push against it.  When installing the flywheel make sure the surfaces are completely clean and then apply just a hint of rust preventative.  Torque the bolt to 55 lb ft.

 

 

It may be too late already. Going on a road trip and by the time I get back, hopefully the major heat wave is over.  Maybe I'll just plan on replacing it either way.  But like I said, I think I'll attack the possible fuel supply problem first. Thanks!