C-120 Automatic restoration

[wheeledhorseman 574]

looking fab Andy ! looking forward to seeing it stickered up

Mark, your wish is finally met!

Even the lights are now working, though the rear one doesn't really show in bright sunlight.

There's still quite a bit to do before finishing. I still have the exhaust system to sort out, wiring to tidy up, a few bolt heads still unpainted, oh and the brake pedal return spring which has decided to detatch itself - a real pain now the tractor's fully back together as its part of the brake/clutch/motion control mechanism

I've still got a couple of decals to put on but I'm not sure if the instructions on the hood really do much for the overall appearance of the tractor even though they should of course be there and there's the small matter of the deck to refurbish.

[meadowfield 2,570]

fantastic !!!

a job well done

mark

[wheeledhorseman 574]

a job well done

Not possible without an excellent set of decals! They really are great. (I'll be needing some for the cutting deck next.)

[meadowfield 2,570]

a job well done

Not possible without an excellent set of decals! They really are great. (I'll be needing some for the cutting deck next.)

as it happens... I have those too, I think I have them in stock as well !

mark

[wheeledhorseman 574]

Just a quick update on progress.

Finally got round to changing the transmission oil and filter. I only ran the tractor round for perhaps 10 minutes before dismantling it but having put it together again and tried it out there was a very noticeable whine from the transmission when working hard. Having read the Sundstrand manual I decided to use an an OEM filter but the big issue was discovering that ATF had been installed previously rather than oil so I drained out as much as possible and replaced it with oil. The transmission was much happier and quieter so hopefully no lasting damage has been done but I intend to flush it out again after a few hours running to minimise the amount of residual ATF in the system.

The tractor now also has the correct knobs on the choke and throttle levers - thanks to Richard for the choke knob. It also has a cutting deck though not the vintage restoration project one. The pressing need for two tractors with grass cutting capability prompted me to buy a later deck model in very good order that could be used straight away. It didn't come with a drive belt so a bit of careful measuring with a rope was needed to establish the length required. The belt arrived today to it was the first opportunity to try the C-120 out in working mode.

Of course the deck changes the appearance dramatically - less tractor, more mower - but I said from the start that it would have to work for its living and it's easy enough to take the deck off again. It had rained earlier in the day so grass got stuck to it but I was pleased at how well it did. There's still work to do on the engine e.g. grinding the valves in but I was surprised how quickly the Kohler settled into some hard work. There was a little bit of blue smoke in the air for a few minutes when it started working hard but it soon faded away so I remain hopeful that I won't find anything too bad when I take the head off.

I mowed about half an acre with it but I thought it better to stop at that point and check things over. The transmission had got up to running temperature with no leaks and everything else seemed in order so the next task is to have the head off, do the valves, oh and fit a proper head cowl that Ian has sent me and hopefully the project will be complete. Oh, and yes, there's still the temporary muffler to replace although the current arrangement has grown on me a bit and I'm putting together a list of decals that I'm going to need for the various new projects so expect an order soon Mark.

[meadowfield 2,570]

looking great - It's a shame I don't use mine for doing the grass, it would make a nice change.

mark

[meadowfield 2,570]

btw...two things,

1. Are you collecting A, B, C and D series horses? you are missing an A-800 or A-90...

2. I have decals for A-800, D-200 and B-111 siz speed on file... :hide:

[wheeledhorseman 574]

Hmm...... good question Mark .

There should be a government health warning about the instantly addictive nature of the . I was sorely tempted to buy an A series when one came up on the bay to complete the set but resisted the temptation as I wouldn't have a use for it. The B-111 was very cheap, has an excellent hood with headlights and a good engine so I bought it for parts really but it's a rather cute tiny 'roller skate' of a so I've decided on keeping it. It's lost quite a few bits over the years so it won't be a proper restoration which gives a bit of scope for some poetic licence. I'll be needing some decals but not the originals. I don't much like the decals they put on these so it will have the standard wheel horse on the hood sides and rear (like the C-120) and I'm hoping you'll do a custom B-111 6 speed in the style of the C-120 automatic. Oh, and of course I'm going to need a set for the D-200 and there's a couple still needed for the C-120. So yes, I will be placing an order soon.

On the C-120 front I've actually finally got round to taking the head off. The gasket had been blowing a bit into one of the stud holes by the exhaust and I also discovered that I'll need to replace the exhaust valve as it has two track lines burnt into the face that are too deep for re-facing so further delay in finally completing the project. There's no scoring on the bore but I think its getting close to its wear limit hence the bit of oil being burnt. For the moment it will do though as major work on the engine would be a winter job.

[wheeledhorseman 574]

EPILOGUE

I was determined to finish the project this weekend so that I can get on with the D-200, well at least as close to the end of a project as one is likely to ever be as there will inevitably always be this and that to do. If there was something to be learnt in this final stage it is that a Kohler will run and the tractor continue to do things long after the engine should have been rebuilt! I suspect many of you out there already know that.

I changed the exhaust valve and lapped the valves in but thoroughly cleaning the head revealed that it had been damaged where the previous gasket had been blowing. The pit was too deep to lap away with very fine abrasive sheet on a surface plate so, determined to get it to run, I resorted to building up the pit with weld through primer which once hardened off was then lapped on the plate.

Given the condition of the engine (it's possible to move the piston from side to side in the bore and to see far too much of the compression ring) I decided to use a cheap head gasket rather than waste a more expensive but much better OEM part. Despite all of this the engine putt-putted to life and ticked over perfectly which it has never done before. It mowed half an acre before the end of the day and after retightening the head down this morning a further acre. Up hill and down hill it didn't miss a beat, there was no smoke and it maintained a constant speed. It was a delight to hear the throttle open up on the governor when engaging the pto and when climbing up hill.

Here she is, engine still running and no smoke despite just having mowed the paddock. Unbelieveable given the fact that the engine so desperately needs a rebuild. It was also an opportunity to discover the delight of mowing with an automatic - set the revs, engage the pto, then move the motion lever forward to the speed of your choice which it then holds perfectly.

As long as she keeps on mowin' then the engine rebuild will have to wait for the winter. A final photo below for Ian who kindly supplied the top engine cowl. It's not quite the right one I think but it looks so much better than the one I made so thanks for that Ian. If anyone in the UK has a cylinder head for a K301 surplus to requirements please let me know as my repair is unlikely to last for long.

I'm beginning to think that when a Kohler K series finally refuses to go anymore that you'll open it up and find the rings on top of the piston!

[Tony S 2]

That's an amazing job you've done there, in a short space of time.

I am sure it will give you years of trouble free service.

Regards Tony.

[neil 2,409]

i have a 12 hp pull start complete engine that is surplus to requirements if you need any parts that has good compression

[Anglo Traction 761]

Cool Job Andy! . Another one saved from the Scrap Yard. It look's really at home there and great pics.

Sourcing a Cyl Head won't be a problem. Your Dipstick handle look's like it could snap if you straighten it?. If it does we can furnish one of those as well.

[John T 9]

Beautiful looking tractor. I have just committed to restoring my 1974 C-120 myself. My dad bought it new. I would like to know if that 3 piece muffler setup is identical to the original, and if so where did you get it? Thanks!

[wheeledhorseman 574]

I left off waiting to see just how long the original engine would keep going. Well the answer was it worked hard through the summer and fall doing 30 hours of mowing in the fields but the end came whilst cutting through long wet grass when it started losing power and eventually had to limp back to the barn only just making it.

As hoped, it had got me through the season but knowing that its life was limited I'd picked up another engine during the summer and earmarked the work as a winter project. It was a pull start magneto general purpose type made by Kohler to no particular manufacturers spec but most importantly it had the same crankshaft, bolts for a starter motor, and I had the opportunity to see / hear it running before buying albeit with no load.

I toyed with the idea of fitting it pretty much as was to keep the tractor going while rebuilding the original engine which I'd already put time and some new parts into. Initial indications were that I might have got away with a new piston and rings or at worst a re-bore but signs of oily gunk between the cooling fins with no visible indication of how it was getting there other than from a crack in the cylinder made me decide to cut my losses and scrap the engine and so the process of moving parts across from one to the other began. Readers that have been there before me will probably smile knowingly at this point as it is not exactly the quick task that it might at first seem as most of the external components need to be removed and transferred across; even the stud that secures the crankcase breather assembly is a different length.

Having got the replacement lump stripped down and ready to receive parts, the visual indications concerning its condition were thankfully good as despite seeing an engine run before buying there's no guarantee that you won't find any problems when you take the head off. The oil pan isn't painted as I'll have to re-use the original one to make future oil draining a practical possibility. Eagle eyed observers will notice that I can't transfer the wheel horse dipstick / filler tube over as the block hasn't been machined to take it. At present there's a plug with stumpy dipstick at the other end which will do for now but the hex plug visible on the top of the crank case is designed for a longer one which would be more convenient if I can locate one. On the plus side, the block had been fitted with a pepper pot muffler allowing for a bit of easy plumbing with iron fittings to achieve the stack exhaust I'd originally intended for the C-120.

In changing a block from magneto to battery ignition, pretty much all the externals have to move across starting with the bearing plate and alternator stator, in fact there wasn't a lot left behind apart from a spare carburettor and fuel pump that will doubtless come in handy sometime. The valves were ok but showing signs of their age so I also transferred the new ones that I'd previously fitted to the other block as it seemed silly not to.

Many hours later and its almost ready to be bolted down to a wooden base for a test run before transplanting but that will have to wait for a few days as I've got to remove the remains of the old lump from the horse and finish rigging up a test exhaust system first.

I'll keep you posted.

[meadowfield 2,570]

great to see you back with some updates Andy!

good luck with the transplant...

mark

[Anglo Traction 761]

Glad to see your overcoming the differences Andy.

Not sure how long it will take you to find the correct 'Top Crankcase Dipstick'!. You can always make your own if you have the correct NPT threaded Raised/Flanged Hex Plug!. Either way , I'm sure you'll sort it...................... Look forward to hearing it is 'Back To Work' for the :wh:

[wheeledhorseman 574]

Look forward to hearing it is 'Back To Work' for the

Mindful of the fact that, if Spring comes early, there aren't exactly that many weeks before it has to be available for work again, I've had to be realistic about priorities and also take into account that I'm still very much still on a steep learning curve re Kohler engines. A year ago I'd no idea what a wheel horse was or, indeed, that Kohler made engines!

The block does have a machined flat surface where a filler tube should fit so if the engine turns out to be a good'un then doing the necessary work to fit it is a possibility but for the future rather than now. Re the need for a raised hex plug, I strongly suspect that I can swap the existing stumpy dipstick over with the top of crank case blanking plug but haven't investigated it yet as I'd then be committed to making a longer dipstick to fit to it. I also suspect that the drain plug on the oil pan that I won't be using is the same size and thread, if so, I can experiment but in reality it shouldn't be too much of a hardship to live with the existing oil fill / level check arrangement for now as there isn't a muffler sitting across the front of the engine.

I've kind of got used to the side mounted mufler now and it will seem strange to be without it but I'm determined to see what the C-120 will look like with a stack based on the Nelson muffler I got last year. Just waiting for a straight threaded connector to arrive in the post - the one thing I couldn't find in my junk box.

Andy

[Anglo Traction 761]

Your thinking exactly along the same lines as me re the Drain Plug for the Dipstick plug, if they are the same size NPT threads. .

Also Andy , looking at the 1st Photo in your 8th June 11 Post, Is that a Volt Meter fitted in lieu of an Ammeter ?.

I'm looking to add one or replace the Ammeter on the C-120, but will be a modern digital one.

[wheeledhorseman 574]

I'm old enough to remember the times when automobiles had ammeters and that they didn't exactly tell you a geat deal so..... yes, that's a voltmeter on the RR panel. Back in 1971 my first vehicle (a mini) had just the customary spedo and fuel guage but soon had almost every guage possible and the voltmeter that's now on the C-120 is the very same one that I fitted way back then.

A digital voltmeter will look good on that panel you've made - just have to hope that the internal damping can give a stable reading with the spikes that the RR lets through. I guess it'll be a case of 'suck it and see'. Although I'm very much into electronics and the digital age I personally still prefer analogue when it comes to meters as they can be read at a glance and give stable readings. I've got several digital multi-meters but my trusty old AVO 8 is never far from hand when it comes to setting things up or checking things out.

Made a bit more progress today by removing the PTO etc from the old engine which is still sitting on the frame. The race slid off the crankshaft but the pulley was rather stubborn - turned out that the original grease had 'caramelized' (if you can apply the term to grease), more evidence I think, that the engine had been cooked at some point in the past leading to its various ailments. Decided to paint the bits that didn't previously get done so they didn't get onto the replacement engine today.

I'll probably get the old engine off the frame tomorrow and have a look at what's involved in fitting the old filler / dipstick tube. I haven't totally discounted the idea but don't want to end up wishing I hadn't started. The iron connector had arrived in the post by the time I got home so I can play exhaust systems tomorrow as well. Iron exhaust plumbing will, I realise, look a bit industrial but then it is a tractor, albeit a small one.

Andy

[meadowfield 2,570]

A digital voltmeter will look good on that panel you've made - just have to hope that the internal damping can give a stable reading with the spikes that the RR lets through. I guess it'll be a case of 'suck it and see'. Although I'm very much into electronics and the digital age I personally still prefer analogue when it comes to meters as they can be read at a glance and give stable readings. I've got several digital multi-meters but my trusty old AVO 8 is never far from hand when it comes to setting things up or checking things out.

Andy

I think the spikes and anomalies can easily be designed out with an RC filter say 100R 100uf, the input impedance of most digital meters is megs so it wouldn't harm the final figure. It's another one of those yet to try's....

Mark

[Stigian 1,234]

Hi Andy, good to see you back, Your C-120 looks great. Glad that top engine cowl came in handy.

I might have the dip stick your looking for, do you have any measurements?

I will have a look in my parts collection tomorrow to see what I have.

[Stigian 1,234]

You have a PM Andy :handgestures-thumbup:

[wheeledhorseman 574]

Progress has been a bit slow over the last couple of days, not for lack of time but the result of needing to clear enough space in the workshop to get the tractor in ready for the transplant. Sharing a hobby with a son who's into restoring things as well is great sharing the available space for the various projects can be trying at times! On the plus side it did allow for thinking about and investigating the dipstick issue.

In the end I decided against making the big hole in the crank case, not because it wouldn't be possible but mainly because the way I'd have to do it would be very time consuming and ideally the engine ought to be stripped down. I did establish though that the casting can be drilled using an HSS bit so I guess it's actually a steel casting rather than cast iron. I contemplated drilling and tapping the crank case for the three mounting bolts so that the correct filler tube could be attached to achieve 'the look' but decided against at this stage as the tractor isn't intended for showing.

So for the moment what I have is the stumpy dipstick shown above. As a dipstick it's fine but as an oil filling point the location is possible but could be better. Finally getting round to removing the oil pan offered the chance to inspect the inner workings and resolve a another little conundrum that had emerged in that, having looked at the original engine, it had become apparent that if the replacement was fitted with balance gears then it would not be possible to use the blanking plug on the top of the crankcase to fit a dipstick. Could it be then that as the facility was there, this was a K301 without balance gears?

Indeed, this turned out to be the case and 'Stigian' has come up trumps with a dipstick that's the right length so thanks to Ian I'll be able to fit one in a more convenient position. Despite the oil pan containing the sludge of ages, the engine is remarkable clean with very little 'lacquering' hopefully confirming my thoughts from the start that it hasn't actually done a lot of work.

Finally getting round to taking the oil pan off also meant being able to check the crankshaft end float. I should really have done this when I installed the bearing plate but as I'd managed to re-use the original gasket and shim gasket, and critical measurements indicated that the two plates were all but identical, I'd taken a gamble and left it till now. My gambleering paid off and the end float came in at ten thou, pretty much in the middle of the tolerance allowed so on with the transplant.

As there was a need to re-use the original oil pan (with its side drainage adaptor) I thought I'd try leaving it on the frame. I also managed to re-use the OEM pan gasket that I'd fitted about a year ago. They are pricey here in the UK but the somewhat rubbery composition together with the fact that I'd used silicone on the surfaces in fitting it meant it came off whole and cleaned up well.

The hoist travels along an I-beam but getting the two large masses to line up perfectly was still going to be tricky so a couple of taps were used to act as locating pins, which was a bit risky as they're brittle more gambleering? With the gasket siliconed, the engine lowered into place without breaking the taps, the replacement engine block was finally bolted down onto its new home.

Before getting on with connecting things up again I just couldn't resist standing the hood in place to see what the new exhaust system was going to look like.

I think it's going to look ok !

Will send you a pm Ian.

Andy

[Stigian 1,234]

It's looking good, but I do like a good stack

Pm about to be answered Andy.

[Anglo Traction 761]

Hi Andy, Motor look's ok inside from the Photo. Good news about no Balance Gears and Ian coming up with the 'Goods' for you..... I've dumped my Balance Gears from my Rebuild and they are now contributing to the Counter Weights for my Garage Door !

I doubt that your Crankcase is Steel , it's the usual Fine Grey Cast Iron. Drills fine once you break the Silicate Skin with a grinder if it's not already a machined area (now an irrelevant. point).

Stack looks good... did you use BSP or NPT fittings?. I'm planning for a Stack (eventually) as well .

Tractor should be back to work soon at this rate :handgestures-thumbup: