Massey Ferguson MF12

I scored a sweet tractor today and based on how beefy this thing is it should be nearly indestructible, I've never seen a garden tractor built THIS strong before!

I present to you my $100 find, a 1970's Massey Ferguson MF12!

I worked on it alot today and made a ton of progress but it's late and I'm tired so I'll just keep to the basics and give it a quick introduction, there's no way I'm NOT building this into a bad@$$ offroader so I figured starting a build thread was the right thing to do!

The Good
- it's built really well and in darn good shape
- it has a Peerless 2300
- the steering feels amazing and doesn't have a ton of play
- all the tires hold air and the wheels are in good shape
- it has new belts (although they look to be wrong)
- the seat is a replacement and in good shape
- it has lots of under seat storage built in
- it has a really well designed hood lock from the factory
- did I mention it's in good shape?!  Lol

The Bad
- it had no engine
- the bottom side of the dash was busted up pretty bad (plastic - I've patched it together)
- the steering must be off a tooth or 2, I can turn way left and not far to the right
- the seat is solid mounted and sits too low on the tractor
- the doofus that owned it before the guy I bought it from cut a hole in the hood

So, I'm not sure if this is a good or bad thing yet but it has a variable pulley working in conjunction with the 4 speed Peerless 2300, it actually feels really solid and I've been told that it works really well on these so if it's good and doesn't cause any issues then it stays which would make my life easier!

I'd like to find a 11hp+ Honda or 13hp+ Honda clone to repower it, my goal is to be able to keep up with my buddys built Suburban which means I'll be searching for about 26mph!

That's it for now, I'll post a big update in the next day or two!

This tractor has some really neat features that will come in handy like the amount of easy to access under seat storage...

...the hood lock that holds it down really securely...

...and a first gear lockout! Anyone ever see this before?

Here's the variable drive control and pulley setup, the control lever has a ratcheting mechanism with a release button like a deck lift handle that makes it really easy to use and reach, it also feels very smooth.

More updates to come soon!

Such a nice machine.  I think there is a MF10 here in the forum a lot like yours.  It was in the B/O the year or just before I joined ATLTF.  I'll add the link to this post if I see it.

Edit:
https://www.atltf.com/t4425-masonmck-s-massey-snow-offroad-rig-aka-the-mule

Call it the big bad mf!

Thanks for the link @MightyRaze he did a decent job building that! Good one @Adventurewagen!  Lol.

It's Labour Day here in Canada and I have the day off but it's supposed to be a hot one so I'm going to tinker until it gets nasty out then post a big update!

I took the belt guard off last night to get a better look at the variable drive system, pretty robust I have to say as it's mostly cast iron!

Is the idler in front of the variator and behind the engine the clutch pulley (between variator and engine)?  The back belt is pretty loose, but that is probably due to slack from the front belt (not installed).  I'm guessing the back idler is just that an idler?

@MightyRaze the clutch is in the form of the variable pulley moving back and forth, all the way forward creates the needed slack to declutch. The front idler I'm not so sure is a drive idler to be honest it could actually be for implements because it doesn't seem to be required but I'm not sure, with a original small pulley I don't think the belt would be anywhere near it and you'll notice in the thread you linked, he doesn't even have it installed! The rear idler is connected to a linkage and spring which is where I believe the adjustment comes from, I'll work on that another time!


Man it's hot AND humid out now but I hit a great milestone before retreating indoors, the big update I've been promising has grown considerably since yesterday so I'm going to try and keep it brief as possible and picture heavy.

Starting where I left off... I put the Honda G200 test motor in but with only 2 bolts and it hanging over the edge! Lol. It has a tapered shaft so I made a adapter for a 1" bore hub from a nut that threads on to the end of the shaft and 3 thick washers, then installed the 4.5" pulley to try it out and it worked well enough to drive it around the yard a little bit!

The bottom side of the dash was broken pretty badly and sitting 2 inches too low so I plastic welded it, made a quick template and used a scrap of sheetmetal and some rivets to hold it together for now, in the future I'll repair/reinforce it with fiberglass matting but for now it's holding together!

I also replaced the steering bushing with a bearing, for once a steering wheel came off without a huge fight!

Now is where things get REALLY interesting... I checked the local buy and sell (Kijiji) Saturday night and Sunday by 10am I was the new owner of a brand new still in the sealed box 14hp Honda clone WITH electric start for the low low price of only $170!! No, it didn't fall off the back of a truck and how it had been up for sale for over a month is a mystery to me...

Unfortunately the muffler doesn't clear the grille but the airbox MIGHT, I'm not sure yet and I won't be doing any modifications to it until it's good and broken in. It bolted up to the original Tecumseh location and the valve cover clears so that's a big win in itself!

I removed the throttle and choke controls from the dash, rebuilt them so they're working well and then rigged them up.

Now comes the part that I thought was going to give me a really hard time but somehow didn't... the drive pulley and a front belt. As it turns out a front MTD VariDrive belt and the pulley from a MST203 are a perfect match for it, I'm sure glad I don't toss this stuff out!

I had previously removed the hub from that pulley and with a quick clean of the bore it's 1" and able to slide onto the motor shaft which enabled me to slide the 1" hub on and mark out how much material to remove. Some clever mocking up, a 1-1/2" hole saw, some dremel work followed up with a few tack welds (for testing purposes) and it's was on! That only took me about an hour which was nice.

I installed a belt guide I found (will build a proper one another day), added fuel and oil and it fired up on the second pull! I warmed it up at idle then drove it around the yard in low gear for a bit alternating the throttle from high to low every minute or so to start the break in procedure.

After the next heat cycle I'll change the oil then continue breaking it in for a couple/few more heat cycles monitoring the oil for metal flake after each cycle. The pulley/belt combo seems to work perfectly, even without a proper belt guide it grabs well and declutches just fine, the only issue is one that was already existing in the form of too much slack in the rear belt which explains why the previous owner said the variable drive doesn't work as well as it should but hopefully it just needs some adjustments! Sadly, I think I'm going to have to cut or modify the front of the belt guard because of the bigger pulley, I don't want to but it's part of the floorboard on that side so I'll need to do something!

All in all this has been a very interesting weekend, the tractor gods are definitely smiling upon me right now!

Brianator wrote:

@MightyRaze the clutch is in the form of the variable pulley moving back and forth, all the way forward creates the needed slack to declutch. The front idler I'm not so sure is a drive idler to be honest it could actually be for implements

OK, I bet it was for the mower deck.  Nice update!

Well it was for something @MightyRaze but now I'm not sure for what!? Lol. Here's a pic of a proper setup, I may utilize it to try and control belt slack.

Speaking of belt slack, I went back out for a bit and found that the rear idler tensioner wasn't even working properly! One of the pins that the pieces slide on was almost worn right through and causing it to bind so I took it all apart, installed roll pins, greased it, put it back together and reinstalled it. It MAY have taken up a little bit of slack (feels like it) but won't know for sure until I run it again.


Something that is going to be an issue for me is the mess that will happen when changing the oil so I backed off the drain bolt enough to measure it so I can get an adapter for 1/8" NPT to make an easy to access drain.

I had another look at the belt guard and it's definitely going to be an issue, because of the way the belt rotates the top half will be pushing into the edge of it... I think I'll bend the end up and hope it's good!


One last thing... a quick glance and I noticed it has the fabled, splined axle 2300 with hubs so that's awesome!

Maybe one of these will help?  I use it on my 75 Sears "phoenix'.  Makes oils draining slow, but it's cleaner.

Drain Hose Linky!

I considered one of those but went ahead and ordered an adapter and a 1/8 ball valve, I want to hard line it while keeping it inside the chassis and have a hose adapter at the end to run down into a drain pan or old oil bottle.

So I was able to locate and download both the owners and service manuals, turns out the rear pulley is a split design that's uses shims to set the rear idler tenison so I'll get into that soon as well as a full adjustment of the varible drive and brake linkages! That rear tensioner definitely needed the attention I gave it so it wasn't a waste of time.

I messed around for a bit after work, I had to see/adjust the shims on the rear pulley, you can see 3 out and 3 in, I moved the 3 in to the outside and it's put the rear idler back in spec according to the manual but that means that the rear belt is just about worn out. It's also gotten rid of most of the slack when it's in 5th or high "gear".

There was still a ton of slack in the front belt so I mocked up the MTD VariDrive rear pulley (slightly larger) and even it had enough slack to declutch so I gave it the same treatment as the other and tested it out!

After some driving around I started having a issue with the rear idler hanging up when letting out the clutch, not only might the bracket be rubbing the chassis but it's definitely catching on another bracket so I'll have to address that.

It was fully declucthing but slipping a bit in 1st "gear" of the variable drive because there's slack and the belt was deflecting like crazy so I'll probably try a comparable sized weld on pulley which isn't as wide and will make the belt ride a little higher, as you can see here there's still enough slack when declucthed that I can pull the belt off the front pulley easily.

So, if a different pulley doesn't completely solve it then I can use that idler that shouldn't be there to control what slack is left. As soon as I go to 2nd "gear" the belt lifts away from it so I think I'll get this sorted out without too much trouble!

Brianator wrote:

I considered one of those but went ahead and ordered an adapter and a 1/8 ball valve, I want to hard line it while keeping it inside the chassis and have a hose adapter at the end to run down into a drain pan or old oil bottle.

This has been on my mind a while now.  Are you going to re-tap the oil drain hole?  I think it is 12mm on the 420.  You know where to find some 12mm hard line.  I'm all ears!

Here's a link to a M12×1.5 - 1/8 NPT adpater I ordered on Amazon!

CLICK - BOOM - BOUGHT!

Thanks @Brianator!

I got mine...    


Just need to find the tube now for later.  Thanks again @Brianator for the tip!

No problem at all @MightyRaze, enjoy!

Here's how I used mine to setup a quick and clean drain, just need to take off the rubber cap, slide a hose on and drain away! I would've preferred to have the lever on the opposite side but the ball valve was a male/female style and I wanted to use as few connections as possible. It's tucked in there pretty well and I doubt a stick could get to it but I'll probably still build a little guard for it to be extra safe.

Luckily I was able to get the front of the tractor high enough to keep the oil at the back of the engine while I installed it!

I've been tinkering a bit after work, first thing was to fix the issue of the rear idler hanging up when declucthing so I took the idler off and ground the edge of the plate behind it but the bracket still felt sticky at the top I'd guess because it hasn't been travelling that high for awhile so I got some oil on the pivot and kept working it until it felt good. While I was there I replaced the idler with another of the same OD but it's a little thinner than the original so it had to be lined up perfectly.

I also picked up a new pulley for the front, same size but thinner so the belt rides a little higher and it seems to have gotten rid of the last bit of slack in the front belt while in first "gear" of the variable drive.

I'm pretty bummed that I'll have to modify the original belt guard but there's not really any other way so I'll do the best job I can to keep it looking stock but before I get into that I need to make sure the drive system works properly and consistently...

...which is hopefully what these belt guides will accomplish!

All 3 are pieces off the Toro mud mower I bought last winter for parts, played with and then stripped down. The 2 lowers just needed a little bending/tweaking and the top one I had to spend some time on, you can't see it well in the pics but there's a stopper bolt for the top guide to prevent it from getting any closer to the belt.


The bolts are easily accessible to swing the guides out of the way so a belt change shouldn't be difficult at all!

I spent alot of time turning the pulley by hand while playing with the guides to see how each one effects the belt and interacts with each others postion until I think I nailed it but until I do some testing and tuning today I won't know for sure...wish me luck!

Looks like someone else has been doing a lot lately! Great update.

This is true! I'd really like to get the drive system working properly so it's not disabled and I'm able to move it around at least. Testing didn't go so well, it ALMOST works but the belt comes way out of the variable drive pulley so it doesn't give enough slack on the front of the engine pulley and the belt keeps wanting to pop off, I might try making a mock belt guard to see of that helps and play around with the belt guides too. I might even have to try to make a guard that wraps around the variable pulley to keep the belt pushing forward for slack.

I'm so close I can taste it but have worked on it so much lately I needed to take a break from it so no work done to it today.

*EDIT* Just to clarify, the drive itself seems to work fine it's declutchung the belt that's the issue.

Well I finally made some headway, can't get the belt to stop completely but it's coming out of the variable pulley enough to declutch and the belt isn't trying to jump off the engine pulley anymore so thats a good thing!

I redid the top belt guide and made a little piece out of flatbar steel to simulate where the end of the belt guard will be after I modify it.

With that sorted out and the fact I've done 3 break-in heat cycles on the engine it was time for a top speed run, it hit 15mph which is enough to feel the wind and clear mud from the tires so that is a good start! I won't be playing with any more pulley swaps now that it seems dialed in so any additional speed will need to be gained with engine rpm and rear tire size, I'll fall short of my goal but I'm really not upset about it and feel I'll be able to hit 20mph which isn't bad at all!

While it was still good and hot I gave it the first oil change with the new setup and it works so well! With the back end of the tractor up it only took a couple mins to drain...

...and as expected of a brand new engine there was alot of metal flake.

Now that the drive system seems to be working well I'll continue breaking in the engine and give it at least one more oil flush then I'll need to modify that belt guard so I can install it. I have plenty of future mods in mind but because I already have working ATTs I can take my time with it, I will be installing a tachometer/hour meter and a tethered kill switch sooner rather than later so I can monitor the rpms and have a quick way to shut it down, as of now I need to lean way forward to reach the key and I'd rather be able to pull the tether to shut it down quick if the need arises.

That's all for now, hope you enjoy seeing this rig come to life!

Whoa, hey! So Im NOT the first one to build a Massey. Did you ever finish this thing?

Lol I'mnot the first either there'sa couple others here. No not even close, this build is still in the starting stage and the motor isn't even broken in yet! I just haven't had the time to mess with it much

I hear that bud loud and clear!
Once you get back on it we can share some ideas with the variable drive stuff, Ive already been tinkering and so far so good! Being able to shift on the fly in the trails is just plain super!

For sure! I ended up picking a engine pulley size to work with a MTD VariDrive (front) belt and adjusting the shims on the rear pulley to tune it in and it seems to work fine but I only have maybe an hour of testing around my yard so far. I'll probably tinker with it over the winter, I do like being able to fine tune the speed with the variable drive so as long as it doesn't give me a big hassle I'll keep it!

Will keep my eyes on this thread, keep yours on mine. We'll figure this variator stuff out together haha.