Dad's old MF smoking

This is my first post so forgive me if I'm breaking a rule posting this here. I'm fairly limited on tractors and mechanical knowledge in general.

My elderly father has an old Massey Ferguson tractor that looks identical to an 8n Ford. I'm not sure of the exact year or model but it's old and basic. Hopefully you guys can still help us out. It had been smoking pretty bad since he got it and he just assumed it was worn out and needed an overhaul. I purchased a rebuild kit for him and took it to a shop down the road.
They later contacted us and said the engine was fine, good compression, etc. He told us that the valves were just worn but it wouldn't do any good to do a valve job on these old tractors. Is there any truth to that? My father doesn't mind the smoking so much as long as the engine is fine. This is a work tractor and not a show piece.

Also, is there a place we can find a diagram with parts or something? We need to replace a seal near the PTO.

Thanks so much!
-MJ

Is the tractor Diesel or gas? What color is the smoke?? Need more information before we can diagnose.

If a shop tells you it's not worth doing a valve job on an old girl the find another shop. It's absolutely worth doing and parts are still readily available.
If it's got good compression then it may just need new seals but depends on the color of the smoke too.

If its burning oil, loose valve guides on the intake valve (engine vacuum from the intake draws the oil in), or the oil rings on the pistons could be worn, or stuck to the pistons. You can have bad oil rings but still have good compression, the oil is sealing the other rings, but the oil gets past the compression rings and gets burned.

Sorry I forgot to mention that it is a gas engine. I'm not sure of the smoke color but I can ask my dad. I feel like it was blue/dark but I'm really guessing since it's been so long. I can find out tomorrow.

I really wanted to see if he was misled or not and it seems to be the case. Like I said, I'm not the best when it comes to engine knowledge but their message didn't make much sense. Although, he did say he could do a valve job but "it wouldn't last long" or something like that.

Sounds like they didn't want to work on it. A darkish blue color smoke is oil burning. If it was running rich (too much fuel) it would be black smoke, burning coolant the smoke (steam) would be white. Does it smoke all the time, or does it only smoke when it gets idled down. Smoke all the time its bad piston rings (oil getting past the rings), only smokes when just idling it down its sucking oil through the valve guides because of high vacuum on the intake side. Look on the side of the engine the distributor is on, there should be a tag above attached to the block with the engine size (example Z129, or Z134). The tractor model, and serial number should be on a plate that's on the dash, but over time they get painted over, or removed to paint the tractor, but not put back on.

The "wouldn't last long" comment made is around the mild steel exhaust valves and seats these came with. They were designed during the days of leaded gas. With todays unleaded and ethanol the valves run hotter and tend to pit the seats. You can have them replaced with hardened ones but need a shop that knows what it's doing. Depending on how much you use the machine it could easily last you another 10-20 years with the standard valves and seats so keep that in mind.

First off, you need to identify what you have, We need the serial number on the dash-steering wheel, and or pictures, which ain't easy cause you are too new on here to be trusted posting pics. Google or Bing Ferguson images, and go to the FENA website and look at pics there.
The YT online shop here will have that PTO shaft seal, only a few bucks, but can take a while to get done right. I will bet the hydraulic fluid is due to be replaced anyway. So you need the repair manual, which is on sale here too, but you need to know exactly what you got.
You already bought an engine kit? But for what engine? A guy not wanting to do a valve job, while you have the whole kit infront of you- don't bother with him anymore. Isn't there a local gear head? Kid into bikes? Someone who is building a rod or into old pick ups? An engine is an engine, anyone who knows what he is talking about will do. It might not be smoke worth worrying about. sometimes a tractor not run much and hasn't been tuned up in years will act like this, they clear their own throat with use.
You aren't stepping on anyone's toes here, just tell us who and where you are, what you got...oh, we don't know.. and ask all the questions you need to, but- you need a operator and repair manual, which are for sale here, so figure out what it is, and get back to us. Welcome to the forum.

Thanks for the reply! It has been a while
since this has happened but I've just been
putting off looking into it further because
my dad didn't want to. The engine is the
Z134. We returned the overhaul kit after
they said it didn't need rebuilding. I saved
the info from his tractor in a note on my
phone but can't remember what is what now:

183-253-m5
Z134a500p

Z134
699276

I will see him today and can get any further
information I've failed to provide.

The tractor is either a Ferguson TO35 http://www.tractordata.com/farm-tractors/001/0/8/1085-ferguson-to-35.html or its a Massey Ferguson 35 http://www.tractordata.com/farm-tractors/000/7/2/729-massey-ferguson-35.html (pretty much the same tractor with some minor changes here, and there). The Continental Z134 engine is pretty common, the exhaust valve seats are inserts, and can be replaced. The new replacement valve seats should made for use with unleaded gas, the valve guides can also be replaced.