My 1977 1250 QL
 

Howdy fellas. After lurking a few weeks and searching/solving what minor issues I could, I thought I would bring my project out in the open as I will likely need assistance and have a few questions. The project in question is a 1977 1250 that has ~400 original hours on it. Admittedly its no spring chicken, but I can tell it led a decently easy life, hopefully without too much abuse, and think the condition was well worth the $250 I paid for it, 44A mower, and the IH front plow I still need to identify. I mowed with it once before the drought began, found several issues which I am still resolving, and am finally at the point (thanks to recent rains) that I need to get it going again to mow the 1.5 acres of lawn surrounding the house I bought not long before the 1250.

Known issues/concerns:

1. Upon 1st oil change (day I bought it) I discovered the only thing holding the 2x oversized oil drain plug in was RTV. Rather than helicoil an already over-sized hole, I tried re-tapping the hole a fine-thread size larger. Unfortunately, despite looking clean/sharp, the new threads did not hold. I should have a replacement oil pan on my doorstep by the end of the week though, so I am no longer concerned with this issue.

2. While looking closely at the pan, I noticed the lower half of both rear ISO mounts is destroyed. Is there supposed to be an upper and lower rubber rear ISO mount, or is this supposed to be one piece of rubber? Thankfully the fronts are both good and solid.

3. Does anybody have any good pics of how the engine side covers are supposed to mount? I have the originals, but they were not installed at the auction I acquired this at. I can see where the larger rear holes mount to the tractor via bolts/wingnuts, but the front/upper bolt holes do not appear to be near any corresponding holes. Also, are these side panels supposed to tuck inside the frame?

4. The local dealer told me to change the trans filter and simply replace any fluid lost out of the hydrostat, rather than change all the hytran due to cost (~$7/qt was quoted). Does this sound right? For some reason this makes my bs meter start pegging.

http://i164.photobucket.com/albums/u...0512121629.jpg

A "glamor" shot, the day I bought it. The exterior was shiny clean, but underneath it had 35 yrs of grease/oil/grass that has since been cleaned to match the exterior. I have both rear hubcaps, but neither of the fronts, and both side engine covers.

http://i164.photobucket.com/albums/u...828122207a.jpg

In the garage tonight, getting ready to remove the engine to replace the oil pan. Just need to unbolt the driveshaft and remove the mounting bolts.

http://i164.photobucket.com/albums/u...0828122213.jpg

Wire harness on right side of tractor. Did IHC use one common harness for these tractors? Mine doesnt have lights, and I am curious if the "pigtailed together" harness is for lights? I may decide to add these later.

http://i164.photobucket.com/albums/u...0828122211.jpg
http://i164.photobucket.com/albums/u...828122211a.jpg

I assume the two extra holes in the front is a dealer "customization." The paint on the seat frame and bolts was perfect until I decided to give my 6'4 self a bit of leg room via the standard slots. For those curious, the duct tape isnt mine, and the seat will likely be replaced after the few mechanical issues have been resolved.

More pics and posts to follow as the work continues....

http://i20.photobucket.com/albums/b2...ell/IsoKit.jpg

You can use whatever fluid you want. Hytran is what is recommended by Cub Cadet for a number of reason. It is less expensive to purchase Hytran at a Case/IH dealer. Take a couple of gallon containers and you can purchase Hytran from a bulk tank.

YES, the QL harnesses were all the same. Lights were optional on the 1250.

:Welcome2:

The side panel front holes do not attach to anything. A spring goes between the side panels to hold them in.

The two wires that are hooked together look like they are the neutral start wires.

The side panels are easy to figure out- there is a bolt at the top rear to hold them in place plus a spring which goes between the 2 panels @ front.


Micheal

4. The local dealer told me to change the trans filter and simply replace any fluid lost out of the hydrostat, rather than change all the hytran due to cost (~$7/qt was quoted). Does this sound right? For some reason this makes my bs meter start pegging.


He's right about that as far as normal filter changes. But seem how you don't know how its been treated, I would put fresh non synthetic hy trans and a filter on it.

Because it's unknown, I'd pull the cover while it's drained and inspect for damage and clean it out real good with carb cleaner. Might be a good idea to pull the axle housings and clean them out as well. The bearings, seals, and gaskets you will need are pretty cheap.

:Welcome2: Good luck with your 1250.

I think hytran is about ~$20 a gallon. I would just get 2 gallons since the history of the tractor is unknown. A new gasket for the rear.. drain it and if it looks clean you can top it up and replace the filter every year (or 2).
I would look visually for leaking seals before hand, but they probably are fine.


Michael

Nice 1250. Personally, I like the look of a Quietline tractor. I think when they are cleaned up and configured correctly, they are a site to behold in a plow furrow or mowing the estate.

Recently, I bought a 1250, too. I call it my 1250 nightmare. It has given me my share of questions, mostly concerning engine vibration after replacing the motor mounts and making the recommended engine cradle modification. I have yet to find a complete solution.

Good call on the pan. When you have the pan off, please check to see if you have balance gears in the engine. I'd like to know if they are in there. I have no knowledge of this is correct or not, but I believe the general consensus is to remove the balance gears, so that they don't explode through the block at a time most inconvenient.

As for your wiring, the two wires that are jumpered together appear to be for the neutral safety switch. That switch is located near the brake pedal rod, under the tractor. If you can start the tractor without depressing the brake pedal all the way, then those wires most likely need to be connected to the switch. I intend to install lights on my 1250 nightmare. I have the headlights and retainer grommets, and need to find some tail lights. The lights and grommets came from NAPA for less than 20 bucks. When I had the engine out of the tractor, I installed the correct light switch and fuse holder, and made a wiring harness for the lights, to be installed later. I didn't find wiring for optional headlights/taillights when I examined the tractor wiring in place.

As for your motor mounts, I would recommend replacing all of the mounts, so that they are all the same. I am plagued with vibration after replacing my ISO mounts with new OEM mounts. The instructions recommend torquing the mounts to 100 inch pounds, but many shy away from this. The diagram shown in a previous post is the diagram of the OEM mount. What is not shown is the torque specification. When I tightened my mounts, the vibration seemed to be a bit less.

Those side panels are a bit difficult to install; at least mine are! The way that I do it is to match the contour of the frame to the bottom of the side panel, and then slide them into place. The rear hole takes a 1/4 x 20 bolt, stove bolt or thumb screw. The forward holes line up with each other and need to have a spring connected between them, over the muffler box.

Hy-Tran works in these Sundstrand hydrostatic transmissions. That is not to say that other hydro fluid won't work, but we know that Hy-Tran works. I think it is about 14 dollars a gallon, purchased in bulk from a Case-IH dealer. Bring your own containers. You probably can get the filter there too. Cub Cadet, Baldwin, Wix, and Fleet Guard are all good brand names. Carquest and NAPA filters are made by Wix. What I like about Hy-Tran is that it has a moisture trap feature in it. You will see that when the transmission is drained. There will be little white granules in the bottom. Wash them out with Carburetor Cleaner. You can get the rear cover gasket from Case-IH too. It is the same as a Farmall Cub.

Good luck with your repairs. As your tractor is identical to mine, even down to the production year, I am very interested in your repair results.


Brian Wittman

As we have been beating to death recently, 100 in-lb torque suggested by CC is to be disregarded. When installing new mounts, use new nylock nuts and original length bolts, tightening them such that 2-3 threads are showing through the nut. This works. Tightening them to 100 in-lb will crush them, as you've probably discovered already.

Matt,

Why, then, do I experience more vibration with the mounts loose in their mountings, such as with the nuts at two threads showing? I experience a little bit less vibration with the mounts tightened down.

Why is it, when I contacted MTD, the parts supplier, that they continued to recommend the 100 inch-pound torque after I explained my problem to them? I asked them about ruining the mounts due to overtightening and they told me that was nonsense.


Brian Wittman

Thanks for the warm welcome as well as the knowledge fellas. As the photo below shows, I was able to get the engine out after about 30 mins work tonight. It was a combination of exciting and somewhat depressing as almost all of the fasteners had their original paint still perfect on them. I must also give IHC credit, previous experience with fasteners on other colored larger iron has been that everything is TIGHT. On this tractor, everything was barely snug, yet no hardware was missing that I can find, and after 35 years I was still able to crack bolts/nuts loose with 1/4 wrench turn then unscrew by hand. Hopefully to contribute an idea for others - I dont have an available hoist as I havent moved most of my tools to the new/old house yet, and rather than grunt it due to the awkwardness of handling, I ran a strap around a long 4x4 to make a "handle" that myself and her could get on each end of. We lifted, and I then fed her the excess length from my side in order to place the engine alongside the tractor without either of us taking a single step.

Found another item to buy - a driveshaft fan. The currently installed one is painted yellow and has no more than 1/2" of any blade left on the hub.

Unfortunately I had a rather busy day today, and have to be up in another 7 hours for another 10 of work, so I did not pull the old pan tonight. I will take a pic or two when I do and we can check to make sure IHC installed balance gears along with any other requests.

http://i164.photobucket.com/albums/u...0829122234.jpg

If I've followed the progression of your posts correctly, you installed the mounts as per the instructions, and squashed the mounts by doing so, since you say the mounts were 'loose in their mountings' when the nut is backed off so that two threads are showing. You permanently deformed them. They would not have been loose if they had not be tightened to 100 in-lb initially, and so they would have worked well like they have for the dozens of other people that have tightened them how I explained, myself included. As I told you either in another thread or on the other forum (or perhaps both) you've essentially ruined those mounts by overtightening them initially, and you will not get the same results as if you had installed them correctly (by disregarded the kit instructions) the first time.

The fact that they told you ruining them due to overtightening is 'nonsense' clearly shows that whoever you talked to has never actually installed those mounts and seen what actually happens. Just because they supply the parts doesn't mean they know what they're talking about. I hate to sound like a broken record, but DOZENS of people have installed the mounts as I've explained numerous times with good results. I've never heard of anyone being happy after following the directions.

You can continue to accept MTD's 'advice' as gospel, but there is a lot of cumulative experience with the installation method that's been provided on this forum and others that proves the instructions don't work.

Being in the HVAC/R trade, there is one thing I have learned a long time ago. A parts guy is NOT a service tech and vice versa. It is fruitless to ask a Parts Man a technical question. They may know how to look parts real good, get the parts you need...... BUT may have never turned a wrench, let alone read or look into a service manual.

Unfortunately, I discover this quite often, more so the vice versa scenario tho as I do the majority of my own work and remain skeptical throughout. I actually experienced it today - received a new oil pan on my doorstep and discovered the gasket the local dealer sold me a few days back was wrong. Luckily, I arrived back at the dealer with 5 minutes to spare before closing and got it exchanged.

I also got a quote on new ISO mounts from the same dealer today and experienced a bit of sticker shock, but thought I should inquire herein about the price. The quote was for $100 for 4 mounts and 2 front rubber bumpers, complete with all of the necessary hardware, which I think is rather exorbitant, but list is supposedly $120+. I see several other aftermarket sources via ebay and others for ~$30, and am curious if anybody has any recommendations or advice?

http://i164.photobucket.com/albums/u...830122220b.jpg

I read/heard somewhere that none of the QuietLines had balance gears, and it is definitely true in my case. The only gears in the crankcase are the cam timing pair.

Didnt get much done tonight, but I did pull the pan off, and everything looked spotless inside. I still need to scrape the old gasket and clean up the new/old pan (gasket remnants) prior to install. Sorry if I am working on this rather slowly for some, but life has been rather busy lately and shop time has been scarce. I am determined however to do something on it every night until its done or Im out of parts however, even if its only 5 minutes and 4 bolts worth.

That's what they cost, but it's worth it. There is no workaround that actually works.

Thanks for the continued support Matt.

I left work a bit early today to pony up at two different local dealers (nobody had 4 mount kits), and for just over $100 came away with four mount kits, two bumpers, and a new driveshaft fan.

Tonight I also managed to get a small bit of work done on the engine and tractor. I cleaned up the new/old oil pan and block gasket surfaces, installed and torqued the pan down to 35 ft-lbs per the manual. In the process, I had the thought that patience now may save me time later - I decided to put a quart of oil in the engine with it outside of the tractor and let the engine sit overnight to guarantee no leaks when I reinstall it tomorrow. I then spent an hour or so degreasing the engine bay and underneath the tractor.

I also discovered a bit of damage. When I pulled the engine, the front mounts were standing tall and strong, but the rears were squashed down to ~1/8" and not doing much.

http://i164.photobucket.com/albums/u...t/leftside.jpg

Right rear engine mount bolt/nut poked this hole in the flywheel cover.

http://i164.photobucket.com/albums/u...0831122100.jpg

Engine cradle appears to have rubbed grooves in the front crossmember. The front of the left groove is untouched and still painted, while the rear of the right groove is worn .150 according to a dial caliper.

Tomorrow Im hopeful to get this tractor completely reassembled within an hour or two after our weekly trip to the farmer's market in the am, do a bit of engine tuning, and maybe even a bit of mowing/testing. Once its running strong and steady, and a bit of mowing has been done, I will look into opening up the rearend to clean out any potential sludge buildup and start on the million other lil tasks to make this tractor perfect again.

Hi justanengineer,


From my experience, a hundred bucks is what will have to be spent on new Cub Cadet ISO mounts and snubbers. I think my ISO's were about $19.20 for each set and one needs four sets.

I am really interested in your experience with these mounts. Next year, I am going to replace mine once again with identical mounts to see if Matt is correct. I don't think the mounts were deformed by tightening to recommended specification. When I loosened them from my original install, they relaxed well and yet, still had vibration. After re-tightening them, the vibration is somewhat less, although it still vibrates more than I think it should.

I continue to be amazed at the diverse opinion on this subject. From what has been discussed previously, there seems to me no correct or incorrect answer; but rather, many different experiences.

Please keep me posted on our progress.



The only things that should be green and yellow are the NDSU Bison. GO Bison!

The new ISO mounts are worth the money. I changed mine on my 1450 about 2 years ago and they are holding up and doing a great job. On my 1450 at WOT there is very little vibration in fact if you put a cup of water on the hood you will see very small ripples in the water if any.

I found many things contribute to vibration and all need to be looked at to get it running smooth. A well timed engine (use a timing light), correctly adjusted carb and new rag joints (if they are old they maybe out of shape and stiff ). Also I found on mine that the engine had a slight tilt to the back (fly wheel side) most likely due to the weight. To counter it I tighten the front ISO mount down a little more than the rear, not much maybe 2-3 treads more. Now the engine and drive shaft are at a perfect 90 degrees.

Time also helps as the new ISO mounts break in they get a little more flexible :biggrin2:

Yes, they were, you said so yourself in this post:

If they were loose with two threads showing, the mounts are permanently deformed, or you're using too long of bolts, but I'm fairly certain you said you obtained new bolts in the correct length. The engine was not loose in the mounts for the many other people that have done this, myself included.

Really? I have been following this subject since I got into this in 2003, and aside from people trying to use solid mounts and chassis mounts in place of the OEM mounts, so for the OEM mounts, there's two routes you can go, and two sets of experiences: follow the directions that come with the mounts (incorrect, proven to not work by you and countless other people that have tried it) and tighten them with 2 threads showing through the nut on the original length bolts, which many people have done since the idea was first posted on another forum 10 years ago by someone who had several QL tractors and experimented with various things and found this method to actually work.

I managed to get the 1250 completely reassembled yesterday and spent a bit of time wirebrushing the adjustable links in the deck.

The good news is that it now holds oil and runs a bit better/smoother than it did previously. On the subject of vibration, its pretty similar to my brother's 147 that I spent quite a bit of time working on everything BUT the engine previously in addition to using. Both tractors vibrate a good bit while at low RPMs, but smooth out nicely at high RPMs, so I believe the new ISO mounts are working pretty nicely. Previously this tractor shook like crazy regardless of engine speed due to flattened rear mounts. For the record, I used the 2-3 threads above the nut method for ISO mount installation.

My question now is how to tune the engine. Despite today's rain, I took it for a test ride to see how it behaved and it still is acting similar to when I bought it. It doesnt idle and seems to have very little power. Climbing a very slight hill (more of a slight rise) in the lawn at low (crawl) tractor speed and high ~3600 engine speed with the mower going requires stopping several times as the engine is "lugging" down close to stalling. It also will occasionally backfire through the carb upon shutdown and/or while cranking.

I have cleaned the carb thoroughly and installed the standard Kohler carb kit for gaskets/needles etc, but something still isnt right. The engine starts right up on 6-8 revolutions, but requires full choke everytime to begin firing, then once firing requires choke off and mid-full throttle to actually run - idle needle too lean maybe? Once running, it doesnt really want to idle. It will run somewhat consistently in the mid RPM range, but doesnt really run smoothly until up around 3600. Ive tried adjusting the needle/jet from the factory settings (2.5 turns out) both directions per the service manual, using the sound of the engine speed increasing/decreasing with a final setting halfway between, and that seems to work for the main jet for the high RPM range, but the idle needle doesnt seem to affect the engine in the least regardless of the direction turned even at full in, which makes me suspect an issue there. Any ideas?

One other thing Ive tried is adjusting the points gap. When the engine was out I found the original points in a glob of greasy crap in the frame so I pulled the cover and found the gap at something over .020. I reset them to .017 and it ran a bit better, but I suspect this also may be a bit off. I tried Matt's static timing method, but unfortunately I cannot see a timing mark close to the opening point. I see a vague one ~1/2 revolution out, but could be seeing things. Is there supposed to be a stamped T and S, or are there simply two dash - marks on the smooth portion of flywheel to the left of the gear teeth? I suspect I need to get in there with Q tips or brake cleaner to clean some rust/crap off the marks.

As always, thanks for all of the assistance. I am hopeful that with your assistance I can get this similar to my brother's 147 - a good solid tractor with plenty of power that runs smoothly, quietly, and is an absolute joy to mow with.

Carl

Your timing is still off. It may be easiest to remove the flywheel shroud and then find and clean the timing marks and then put some paint in them. They are stamped in the flywheel, sometimes a bit too lightly. If they are rusty at all they will be nearly invisible.

Matt,


Just a comment on the iso mount instructions- could it be that they are correct IF you use a new IH metal locknut? Metal deformed locknuts take more torque than a used one or nylon-locknut.
I used the 2-3 thread rule and locktite on the old nuts.


Michael

Not to get too off topic but I could believe it Michael. When I replaced the bushings I used metal deformed nuts from TSC, and I could be wrong but believe I close to if not over 8 lbs-ft at 2-3 threads.

On the off chance that someone here is a big box store shopper for common hardware I thought I should give a price comparison between the local Lowe's which is a few hundred feet from my home and TSC which is a few miles. Four (4) 3/8-16 grade 8 black oxide finish metal deformed "nylock" nuts - Lowe's = ~$5.50 TSC = $0.18. Hopefully not many here are silly enough to buy by the piece when you can buy by the pound.

Who knows? Unless we know the running torque of the locknuts they used when the wrote the instructions, and use the exact same locknut, the resulting amount of compression probably won't be what they intended, and what they intended may not be right anyway. As I recall, the instructions don't specify, and there may still be variation between brands. And as you probably know, the metal ones are one-time use, and some people don't know that and will try to re-use them, so then the amount of compression would be different then too.

This is why using nut torque to compress the mounts is ridiculous; the results will be very inconsistent. 2 threads above the nuts on the original length bolts is pretty consistent, with only slight variation due to nut height.

Thanks for sticking with me on this fellas. Ive spent the last several evenings tinkering with this tractor to fix/adjust as many of the lil issues as I can to improve its operation. Luckily for me there arent too many, but a few did leave me scratching my head and looking for a monkey with a wrench.

At this point in time I believe I have the timing adjusted pretty close to what it should be. I tried Matt's static timing method several times, but unfortunately this resulted in rather late ignition as evidenced by frequent backfires and poor running overall. On the positive side, it was easy to perform. I then tried a timing light, but found it rather difficult to adjust timing with any consistency, so I settled for "decently close" being ~.017 as I originally thought.

While experimenting with timing, I noticed that the throttle and choke linkages didnt quite look right. Sure enough, according to the book the governor linkage was set for the LEAST sensitivity, and this engine never seemed to have much power due to a lack of governing. A few trials later, I came to the conclusion that the 4 least sensitive positions (closest to end of governor arm) resulted in no/almost no governing. Coincidentally, at all four of these positions the engine will reach full RPMs without issue, but under load it lugs down until it stalls or load is removed. With the spring hooked into the fifth position, the tractor will happily chug up and down hills while mowing without issue and appears well governed, but unfortunately will not reach full RPM with the mower deck engaged. Despite the throttle being wide open, the governor keeps the engine at relatively low speed (~1400) under load, which means the mower barely spins fast enough to cut and not enough to cut at any normal tractor speed. Without the mower engaged and simply driving, or if I push on the governor arm/carb throttle arm it gets up to ~1800. Ive tried adjusting the link between the governor and carb, but had no success. Its possible via this link to lower the top speed by lmiting max carb open, but doesnt appear to increase it. Ive considered putting more tension in the throttle spring adjustment, but hesitate to do so as I think it will just hurt the governing.

Any ideas?

Reset the governor arm as per the manual and put the spring in the original holes (probably the ones with the most wear, it may be obvious). There is no need to put the spring in any of the other holes. If the governor isn't working properly with the spring in those holes, something else is wrong. I will also add that a lack of power can be caused by the timing being off. I'm not sure why you're having so much trouble with that...what kind of meter are you using?

thanks for the comments back.. absolutely the instructions don't state anything.. the should include a new proper nut, if that is what is required for the 100 in-lbs to work.
Did ppl use a small enough torque wrench? If your in the bottom 20 % of the range, the tw's can be off by quite a bit.

In the airplane world, we specify running torque. The mechanic must determine the initial torque for the lock nut, then add that to get the total torque. There is a mil-spec for new and min-reuse for locking nuts. Nylon ones are limited to exposure <225 F.

I didn't realize you could buy them reasonably for a box. I did splurge and get the bevel locking washers and heim ball joints for the cub.

A big public THANKS to Matt for answering my questions.

Just thought I would post an update on my 1250. After a small break which was spent between the house and a few other projects, I dug back into this last week. Initially, I decided to pull the flywheel cover and locate the timing & tdc marks. I was able to find one through the timing hole, but not the other. Unfortunately, I decided after 5 mins effort that removing the cover with the engine in the tractor is a royal PITA, so sought out another option. I then removed the tin to access the head, removed the head, and squeezed my hand between the flywheel cover and the block at that point. Removing the head to access the flywheel allowed me to 1. locate the two marks on the flywheel, and 2. decarbonize the engine. A quick minute with some 120 grit paper on the flywheel, and a few more with a soft wire brush on the head, piston, and deck surface, and the first two tasks were done. While decarbonizing, I also thought it prudent to pull the side cover and adjust the valves while I could easily/visually discern TDC.

Things I discovered:

1. My previous "guesstimate" based off the seat of my pants and experimentation regarding timing was off a few degrees, but close. The mark I located through the hole was the TDC mark, and thus setting timing to it resulted in the backfiring and lack of power I experienced earlier, followed by my experimenting. I fine tuned the timing based off of the timing mark that I located by sanding the flywheel.

2. ~400 hours carbonized this engine a good bit, and I was surprised by how much came off once I started scraping bc initially I didnt think it was too terrible. Reinstalling the head, the head gasket looked strangely good with only a slight discoloration in one small area of the fire ring. Bc it appeared almost brand new, being a cheap SOB, and bc these are air cooled, I simply reused the old gasket and torqued to factory spec.

3. What I suspect is the biggest change - Despite the valve lash on the intake valve being within spec, the exhaust had ZERO lash (or at least .003" shim stock wouldnt fit, which was the thinnest I had), and I suspect most of the exhaust valve sealing was done via the carbon buildup (aka, the exhaust valve wasnt closing fully). While cranking for startup, the tractor now fires significantly harder/more violently during the first few revs before the engine really "catches" and I suspect the compression has risen significantly bc of this.

The result - EASY starting, ZERO backfires, and a TON of power. I was able to give this the acid test - having her mow the really thick, weedy, knee deep backyard acre, and it passed superbly.

Thanks for all of the help thus far fellas, especially to Matt for creating the various downloadable how-tos. I have learned a lot in a short time and hopefully will continue to do so.

I would strongly suggest a new head gasket. They permanently deform a bit when the head is torqued initially, so it's probably not going to seal right the second time around. The fact that the head is aluminum and the block is iron makes it worse.

Not to mention there is a lot of crap to remove and put back on when changing the head gasket on a QL, so it's best to only have to do it once ;)

Well after you have done everything mechanically done on a QL there one of the best tractors to use for mowing. I put all new ISO mounts on my 1250 and i love it, don't vibrate as bad as it did. But make sure your drive shaft is good and the fan is in good shape for optimum cooling. 1250s are powerful on my account. I love mine. if i could own another one i would. and good luck.:Cub7: