42a707 Won't Start - Troubleshooting help

[Madscrills]

Preface: I already searched the forums and found a thread or two on similar issues already but they go into some detail that I'm unfamiliar with. Thus this thread.

A little background here. I'm a 27 year old male Computer Network Engineer with limited mechanical training. Though my father is a master senior technician for Ford so I think, with a little guidance from the pros here, I can probably get this old mower working again.

Was working before winter set in but now I turn the key and I hear a slight click but that's all it does. Where do I start with this? What tools will I need to borrow and are there any manuals readily available for doing any of the work I might need to do? I'm technically inclined and can follow directions pretty well I'm just inexperienced. Any help is appreciated. Thanks!

 

[YT125]

How old is the battery? Is it charged?

 

[reynoldston]

Low amperage. Start with the battery cables, loose or dirty connections, bad cable, Check the battery as in earlier post, The starter solenoid could have bad contacts, bad starter??? If that all checks out good get a wiring diagram and check out all your safety switches. This should give you a good start.

 

[Mikel1]

Yeah I would check to see what the battery voltage is. If low then charge back up. If there is still no change then have battery load tested. This can be done for free at most auto parts stores. Like reynoldston said check your connections.

 

[Madscrills]

All great suggestions. I'll start with the battery and then keep you all posted on my progress(My first instinct as well). Thanks fellas.

 

[YT125]

As a side note these Briggs opposed twins have an undersized starter so a good battery is a must

 

[Madscrills]

Great news everyone, I had the battery tested and it was totally dead. Bought another one and changed the spark plugs for kicks and she started right up.

Doing all this research on possible issues has got me thinking though. Are there some other things I could/should do that are within my realm of mechanical skill to improve the health and longevity of my lawn tractor?

Here's a list of things I could do off the top of my head.

1.) Change the oil
2.) Sharpen the blades
3.) Clear debris
4.) Re-Wire the tractor. (A lot of the current electrical wiring looks like it's been previously repaired with a lot of electrical tape).

Thanks for all of your wisdom to get my mower started again but now help me keep it running!

 

[bertsmobile1]

you can not change the oil enough on these motors as there is no effective filteration.
Check the valve lash every season & adjust as soon as you see problems.
Take some compression readings wet & dry and keep them for refference.
Do it every season at THE END of the season along with an oil change.
They should slowly be going down as the engine wears when you get a sudden change then you know it is time for a valve job & new rings.
Caught early you can get 2 to 3 sets of rings out of a piston but once they start fouling the plugs, it is too late.
Clean the battery terminals and coat with liquid electrical tape.
I use long coach bolts fixed with wing nuts and leave the far end bare so there are contact points for chargers & jumper leads.
Blow the deck and around the cooling shrouds regularly to keep them clean & cool, A 2' to 3' duster gun is good because you can slip it under the engine shrouds and then do the under side of the chassis without eatign grass for a week.
Every thing that moves agains something else gets lithium grease and be heavy handed.

 

[Madscrills]

Great information Bert, thanks!

Also in my zeal I forgot to mention a few things about the mower that I forgot to mention beforehand. Upon doing some research I remembered that back when the mower originally stopped running the engine would start to try to turn over but wouldn't even make it a full rotation. After a few more tries of this is when the engine seemed to stop trying at all. I tried turning the top by hand to see if it would still spin freely and it would not. It had seized up. Upon doing a little research I learned that usually meant that the compression was making it so that the engine couldn't turn anymore and removing the spark plugs would relieve the pressure and allow the engine to spin freely again. Hence why I ended up just replacing the spark plugs altogether.

In any case, could that be the beginnings of a larger problem down the road or was that likely just due to the battery going bad? Is there a way to prevent the engine from seizing up once the new battery eventually bites the dust?
Also, it seems to only really like to start easily if I set the throttle to full and pull the choke out. That's how I've always had to start it, is that normal or is there a way I can help it start easier and only have to choke when it's flooded? Thanks again for all of ya'lls expertise with this, it's really helping.

 

[bertsmobile1]

What you have described is typical of too much valve lash which defeats the decompression at start up so the started can just not turn the engine past TDC on firing stroke.
Usual test is to try plugs out. If the starter spins freely then system is OK
You can also try with the plugs loose in the head, same story, if it fires right up , check the valve lash