engine trouble

[starnsrd]

I have a 2007 John Deer tractor with a briggs and stratton engine with 508 hours, the oil has been changed every 25 hrs and the oil filter changed
every 50 hrs, the engine runs great for about 1 hour, while the engine is under a load, blades turning, the engine will stall until the blades are disengaged
then runs good again just moving forward, the only smoke i see is coming from the fly wheel when I stop the engine, does not burn oil, any comments would be
greatly appreciated

 

[StarTech]

Need more info. As my all seeing eye is on the blink as I haven't two pots of coffee yet this morning.

There is a lot different JD tractors and mowers all with different engines.

 

[starnsrd]

Im sorry failed to mention, its 21 hp OHV Twin V

 

[StarTech]

Being a V-twin you may have an ignition coil or spark plug failing. They can run fine off load but fail when loaded.

 

[starnsrd]

the spark plugs have been changed, and both cylinders are firing

 

[ILENGINE]

the spark plugs have been changed, and both cylinders are firing

At the time of failure or when just running.

 

[hlw49]

pull the engine blower housing and see if the cylinder fins are clogged up.

 

[bertsmobile1]

There are way too many things that it could be
None of us feels like rewriting the 200 page B & S manual or the 400 page J D manual
So lets start with the model type & serial numbers from your engine so we know exactly what engine you are having problems with .
There is a lot more to proper engine maintanance than just changing the oil & filters
When was the last time the valve lash was checked ?
at 508 hours it should have been done at least 2 it not 3 times

If I under stand what you are saying, the mower starts fine then cuts fine for about 1 hour then it will stop unless you turn the blades off

So when were the spindle bearings last replaced or even greased ?

If you turn the blades off then back on again does the problem take another hour to reoccur or dose the engine instantly stop ?

If you pull the choke on does it make a difference ? if so what happens ?

After it goes bad how long do you have to leave the mower before it works normally again ?

How old is the battery ?
If you charge the battery overnight does it go longer before giving you problems ?

 

[starnsrd]

There are way too many things that it could be
None of us feels like rewriting the 200 page B & S manual or the 400 page J D manual
So lets start with the model type & serial numbers from your engine so we know exactly what engine you are having problems with .
There is a lot more to proper engine maintanance than just changing the oil & filters
When was the last time the valve lash was checked ?
at 508 hours it should have been done at least 2 it not 3 times

If I under stand what you are saying, the mower starts fine then cuts fine for about 1 hour then it will stop unless you turn the blades off

So when were the spindle bearings last replaced or even greased ?

If you turn the blades off then back on again does the problem take another hour to reoccur or dose the engine instantly stop ?

If you pull the choke on does it make a difference ? if so what happens ?

After it goes bad how long do you have to leave the mower before it works normally again ?

How old is the battery ?
If you charge the battery overnight does it go longer before giving you problems ?

no need to re- write the manuals. i can get those myself, the spindals were changed 2 years ago, and greased every 50 hrs since then, the battery is 4 years old, changing the oil does not keep an engine running, I agree, needs gas in the tank, how you like those apples. but you mention checking the valve adjustment, should be done every 200 hrs, has not been done, i'll check on that, thanks for your advice

 

[bertsmobile1]

We all approach the forum differently
I for one have a set method.
I ask questions that help me and others to diagnose the problems presented and some times even give the poster tests to do.
When the questions get answered and the test results posted then a diagnosis can be attempted or further testing requested.
Your problem could be electrical , mechanical , thermal or fuel related or even a combination of any or all of them .
I could probably write down better than 30 things that could be at the root of your problem but as perviously mentioned, no intention of writing a service manual.

the spark plugs have been changed, and both cylinders are firing

But are they still firing under load after an hour ?
Did you install a pair of in line spark testers to confirm this ?
Do they continue to fire right up untill the engine stops turning or do they stop firing before the engine has wound down ?

I asked 6 questions, you answered 2 of them
If you don't help us we can not help you
It is as simple as that