Why could JD 425 use oil after replacing plastic with metal cam gear?

[Rob50056]

My JD 425 didn稚 use any oil when it had plastic cam gear in it but after replacing with metal gear,new tapets,heavier springs,and compression was very good in both cylinders.I replaced govener,govener arm,basically the kit one can order online to do the whole job.
It runs much stronger than it did before and I致e looked for oil leaks which there are none.
It痴 using about 1/8in on the stick every hour added on odometer.

I知 guess maybe valve seals because compression test on both cylinder was very good.

 

[oldnslo]

What do the spark plugs look like? If one cylinder is burning oil that plug should show the evidence.

Is it possible one of the head gaskets is leaking once the engine gets warm?

 

[tomplum]

One thing I've noticed on these horizontal twins is that a small external leak- even something as little as a dipstick seal can turn the breathers into a little oil pump. How much volume depends on the leak. Think your way through the possibility of a breather valve or leak issue. It may be easy and cheap.

 

[Gittyup]

The key might to find out where the oil is going. Is it burning it or leaking it? Does it smoke? Plugs look clean? The front seal can be problematic for leaking on these repairs. As can be valve seals or valve cover gaskets. What does the radiator fluid look like?

 

[Rob50056]

I let an inexperienced mower borrow machine and they used it to mow leaves 1-2 foot thick until motor dies and it clogged oil filter and now it has so much blow back it pours oil into carburetor and one piston only has 70lbs of compression.
Right after the metal cam gear replacement it got 190lbs per cylinder.
Motor needs rings,perhaps pistons,and who knows what?
Why do people drive a machine like a sixteen year old child.

 

[radios1]

I let an inexperienced mower borrow machine and they used it to mow leaves 1-2 foot thick until motor dies and it clogged oil filter and now it has so much blow back it pours oil into carburetor and one piston only has 70lbs of compression.
Right after the metal cam gear replacement it got 190lbs per cylinder.
Motor needs rings,perhaps pistons,and who knows what?
Why do people drive a machine like a sixteen year old child.

THAT was not the cause, it's a garden tractor, designed for heavy mulching, plowing, towing, etc. it's not a toy that needs babying.. there is another cause of the problem..

 

[beenthere]

Agree with radios1's assessment.

But now time to move forward Rob50056, to getting the motor repaired and running again. Wish you well, and wonder if this is work you will do ?

 

[radios1]

Currently, there are 3 or 4 threads on this same machine concerning problems. If you go back and follow some of the older threads on the same machine, things get interesting. I think there is more going on here that we don't know about.

I think a Moderator should have a look..

 

[BCWoodtick]

Rob, did you pull your head to inspect the Pistons? I just recieved my parts and getting ready to finish and wondering if I should inspect while opened up?

 

[radios1]

I have him on my ignore list..