Marvel Schebler TSX tractor carb rebuild

[FergusonTO35]

Nope! Guess I better do that, huh? I was a modern car mechanic for my first career so working on this 66 year old thing is always a learning experience!

 

[Larry B]

Nope! Guess I better do that, huh? I was a modern car mechanic for my first career so working on this 66 year old thing is always a learning experience!

Remember you have to use at least 60 year old tools or they won't work on that tractor.

 

[FergusonTO35]

Well crap, no wonder I can't get anything fixed on it! I have an S shaped wrench that supposedly came from a Ford N series tool kit, if that would help.

 

[Steve]

Nope! Guess I better do that, huh? I was a modern car mechanic for my first career so working on this 66 year old thing is always a learning experience!

I work on modern cars for a living! No matter how much stuff they put on cars, you can't forget an engine is still an engine! Had a honda a few months ago that bounced around different shops before the other good tech I work with found it's exhaust valves where too tight. Simple valve adjustment and it was a new car. I see people daily throw all sorts of sensors and tune up stuff on a car for a problem only to find out it has a broken valve spring or a bent rod.


You know what you are doing. Don't over think it.

 

[Larry B]

Electrical and mechanical troubleshooting skills are overrated. Why troubleshoot when you can just throw parts at it and hope something fixes it.

 

[Al Smith]

It might sound odd but I had one swallow a valve .Not really it just broke the spring retainer because those engines or at least the Z-120 won't completely swallow one just make it rattle up and down .I turned out another one popped the valve up using a piece of rope and put it back together. Didn't need to pull the head .

 

[FergusonTO35]

I work on modern cars for a living! No matter how much stuff they put on cars, you can't forget an engine is still an engine! Had a honda a few months ago that bounced around different shops before the other good tech I work with found it's exhaust valves where too tight. Simple valve adjustment and it was a new car. I see people daily throw all sorts of sensors and tune up stuff on a car for a problem only to find out it has a broken valve spring or a bent rod.


You know what you are doing. Don't over think it.

Thanks. The gears in my mind turn slowly, but they get there eventually. Every car/tractor/mower problem turns into an episode of Columbo.

 

[Larry B]

A couple things you might try before tearing into the engine. Do the wet/dry compression test and do a cylinder leakdown test. The leakdown test is a good test for checking valve sealing. A leakdown tester in not very expensive.

 

[Al Smith]

Usually if it isn't burned up you can hand lap it and get by .If so with the head off go through all of them .Fact if there is enough meat left on the seats do a triple grind .
The Fergy I have at my shop the valves were shot so it was new valves and insert seats on the exhausts .Then don't you know I ran the damned thing out of water .It got the piston rings so hot you could bend them like a noodle and one of the seats fell loose .So it was new rings and the old trick of dimpling the seat pocket using a tool to reseat the seat then a center punch around the seat to stake it in . No problem yet in over 35 years except I check the water level more frequently .

 

[Al Smith]

Now saying that as usual another story evolves .Briggs pancake 18 HP I bought the mower for next to nothing .The dealer, dumb azz he was told the guy a mouse built a nest in the engine and sold him a $5,000 zero turn .About 45 minutes an hour after I got it home I was mowing my lawn, same deal a seat fell out . All I can say is it must have been Mighty Mouse to get by those valves . BTW that dealer also sells Stihl products .--I'll just stop right there ----

 

[timg]

One thing I would suggest to you when you get that old tractor figured out is this. Use a lead substitute in the gas. Most good auto parts still carry it. That will help prevent valve seat and face wear with the new unleaded gas used. Unfortunately when they took the lead out of the gas a lot of lubricity was lost in the combustion process causing accelerated valve train wear. And that tractor was produced in a leaded gas era. Modern engines use a different alloy/stellite combination to combat lead free gas and eliminate the wear.

 

[FergusonTO35]

Thanks. I am going to adjust the valves and treat it with Seafoan before I do anything else. Yes, it is going to get a compression and leakdown test before I go further on mechanical repairs. I hand lapped alot of crusty valves on Toyotas and they usually cleaned up pretty good.

 

[Steve]

One thing I would suggest to you when you get that old tractor figured out is this. Use a lead substitute in the gas. Most good auto parts still carry it. That will help prevent valve seat and face wear with the new unleaded gas used. Unfortunately when they took the lead out of the gas a lot of lubricity was lost in the combustion process causing accelerated valve train wear. And that tractor was produced in a leaded gas era. Modern engines use a different alloy/stellite combination to combat lead free gas and eliminate the wear.

Yup! That's why I had the machine shop install modern seats and valves when I built my VAC engine.

 

[timg]

I thought I had an old working Deere of 60 years. Dang Steve your old VAC is close to 80 years young.

 

[Steve]

I thought I had an old working Deere of 60 years. Dang Steve your old VAC is close to 80 years young.

It's a 51'. So 70 years!

I even just ran outside and got a pic. Just for you Tim!

 

[timg]

Franks, Least in I gotz an orange bullseye for the weekend shootz.

 

[Steve]

Franks, Least in I gotz an orange bullseye for the weekend shootz.

You wouldn't dare shoot Old Abe?!!

 

[FergusonTO35]

Played hooky from work this morning to fiddle with the tractor. Turns out most of the valves were too tight! Cold spec for intake and exhaust is .015, some were as little as .003! Got them all set, will put it back together this evening. As an aside, it is really nice to work on something that has been cared for. Most valve covers i popped when I was in the biz were filled with petrified crude.

 

[Steve]

Played hooky from work this morning to fiddle with the tractor. Turns out most of the valves were too tight! Cold spec for intake and exhaust is .015, some were as little as .003! Got them all set, will put it back together this evening. As an aside, it is really nice to work on something that has been cared for. Most valve covers i popped when I was in the biz were filled with petrified crude.

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That's cuz you worked for yoda. Them things are always horrible for sludge.

 

[FergusonTO35]

Ok, buttoned her back up enough to run and started it. The valve train seems to run smoother, however the miss is still there. I put fresh gas and a whole can of seafoam in it, gonna let it run awhile and see if any improvement.