M18 Starting Problems

[jchamberlin]

Well gang, after re-building not one, but two decks, and mowing my own and my neighbor's grass twice, I managed to get to the back of the shed and pull the M18 out of the 782. I think the pictures will reveal why the motor is not starting.

The cup used to have a steel pin in it that sits in a corresponding hole in the flywheel, it will need to be replaced (sorry for the fuzzy picture).

I also think I'll put in a new seal while I have it open.

The owner of the engine alluded to the "history" of the engine. He wasn't present when I picked it up, he was working. He's got my attention now. It seems as if something got into the blower compartment, judging from the state of the fan on the back of the fly wheel. All the fins are damaged from rubbing, and one of them has been broken entirely.

I did find a part that I was missing on the front under the PTO, actually, there should have been four (4) of them, one for each mounting bolt --it popped out when I pulled the flywheel off.

The take-away from all this?

When checking out an an engine for puchase, it is really easy to bring a 9/16" socket with a short extension on it to pull off the rear drive cup to check to see if the key is intact. I'll know better next time.

Parts Count so far:

1. Oil Filter
2. Remote Oil Filter Mount (with hoses)
3. Flywheel key
4. Drive Cup
5. Blower Fan (Plastic)
6. Oil Seal (Optional)
7. Carb Rebuild Kit (Optional)

Anyone think of anything else while I've got it out?

On the bright side, at least one of the two cylinders seems to be in good shape; I might as well pull the other head to get a complete assessment, since I have it out of the tractor and up on the bench.

I'll post again when I have it back together in the tractor.

 

[jchamberlin]

Finally got back on the M18 today. I grew tired of waiting on my local Kohler dealer trying to get in a replacement key. He was able to get the oil seals in a timely fashion, but the keys (I ordered a spare) was back-ordered --twice. In desperation, I took the shrouds off my OT Sears motor, removed the flywheel, stuck the key in my pocket and went in search of some key stock. Nobody seems to carry key stock anymore, but Tractor Supply stocks at least two lengths of pre-made keys by Hillman. A 3/16" square x 1-1/4" long key which cost me $0.52. I informed the Kohler dealer of my find and canceled my order (the key was $3.50 from Kohler).

Trouble is, when I came home to put the flywheel back on, the key was loose and "wobbly" in the key way. I went back to Tractor Supply and picked up a 1/4" square x 1-3/4" long key, but it was too big. Believe it or not, I cut the key down by chucking a 3" cut-off wheel into my 8" drill press and trued up the key in the vise. It wasn't perfectly flat, and it wasn't perfectly square, but by golly it fit tightly side-to-side and wasn't so tall that it interfered with the flywheel installation.

I prepped the shaft with both a flat file to remove the burrs, and polished it up with a strip of sand paper (I don't have emory or crocus cloth); in like manner, I tried to clean the flywheel with a rat-tail file and the same piece of sandpaper. Finally, I sprayed everything with WD-40, wiped it off, and sprayed it again before assembly.

When I tried tightening bolt on the cup, it seemed to a bit "stiff." I pulled it back out, and discovered that one of the first threads on the bolt was damaged. So I cleaned up the threads on the bolt, and the crank until it turned free and easy. Finally, I assembled the flywheel to the crank, inserted the key and tapped it below the level of the flywheel, but above the level of the crank, and torqued it down to 40 ft-lbs per the manual's instructions. But in light of the damage to both the crank and the flywheel, I went another 10 ft-lbs to 50 ft-lbs total (although I would have been happy to crank it on down to 80 ft-lbs; I remember the 16 HP Briggs & Statton specified 140 ft-lbs on an 1-1/4" nut).

Anyway, the motor should be ready to start tomorrow. I'm hoping my son shows up so that I can have a witness.

Pictures tell the story of what I found upon dis-assembly, you'll have to take my word on the assembly steps as given above.

After I got it all together, I came back inside and looked up the parts myself (which I should have done to begin with), and discovered to my surprise that the key SHOULD have been 3/16" square. But I know for certain that if I had put a 3/16" square key in the keyway on my motor that (1) the timing would have been off by 1/2 a tooth on the ring gear (it wobbled from peak to valley), and (2) I could very easily have created the same situation which led to the last key getting chewed up. So I'm happy with what I've installed, we'll see if the motor starts, and then go from there. I really want my red machine back in operation.

Parts Lookup Diagram and Component list:

1862 Flywheel Components S/N 800,000-821,059 140-681-100, 141,681-100 [S/N 821,060 to 836,000 is the same for this assembly]
1 KH-52-025-36 Flywheel
2 KH-52-468-15 WASHER
3 KH-25-086-24 Screw, Hex Mach, 3/8-24 X 1.25 Lg
4 KH-X-286-17 Key, Square, 3/16 X 1.37
5 KH-25-157-01 Fan
6 KH-25-112-04 Spacer, 1/8
7 KH-25-086-21 Screw, Hex Wash Hd, 1/4-20 X .62 Lg
8 KH-25-162-02 Screen, Grass
9 KH-52-755-61 Kit, Drive Cup | (Includes Ref No. 2)

 

[jchamberlin]

This is what I mean by installing the key so that it can't interfere with torquing down the flywheel on the tapered shaft, and at the same time leaving enough that you can knock it out of the crank upon dis-assembly.

Below is the key I was able to purchase at Tractor Supply which SHOULD have fit, but was, in fact too small. The key I removed from the OT Sears tractor was 0.877" long; I went back with my custom width key at the same length as the flywheel is thick --1.171" long versus the MTD specified length of 1.37" long. I feel it IS important to install a key that is long enough to engage both ends of the keyway-- because the the shaft on the crank, and hole in the flywheel are tapered, and the key is straight --the engagement point slants across key diagonally. Thus, a key that is too small in squareness, or too short, can easily get "rolled" in the keyway, which is what I suspect happened to the key installed in the motor before I got it.

If you look closely at the pictures of the crankshaft, you can see where the "rolling" started at the center of the taper --I don't think the key was long enough for the keyway.

Anyway, that is what I'm THINKING happened to the key, I've already noted the damage to the fan, and there is more in the post which follows this.

At any rate, the key pictured below is 1.25" in length; the same size key is also available in 1.75" length at Tractor Supply which can be trimmed to the length specified in Parts Lookup (1.37").

Personally, I think you need to take the info from Parts Lookup with a grain of salt, in this case, the keyway in the crank has a radius on the engine side, so if you select a key which is too long, and try to drive/torque it down, it could either keep the flywheel from engaging the crank fully because it jacks the flywheel off the crank, or prevent you from fully torquing the flywheel down because it is too long. Which may be why the use of WD-40 was universally adopted by the guys I worked with at the feed mill. I found that the keyway and key seemed to attract all the lubricant I sprayed on the crank.

The mechanics I worked with were very careful at this point of assembly, that is, putting a pulley on a shaft, because there are so many ways these things can fail. We haven't even gotten into the issue of alignment . . .. So I don't feel it is a waste of time to "obsess" about it, or spend a lot of time posting about it.

Look at it this way, if you don't do it right, you could wind up creating the kind of problem I'm trying to fix.

 

[jchamberlin]

Well, this post comes under the head, "BE CAREFUL WHAT YOU WISH FOR."

I vowed that I would get this motor started before dark today, and about 1/2 hour after dark, I managed to try it and it started on the first try --but-- it started to race to the MAX RPM when it was only set at half throttle.

So I put everything back in the shed, turned out the light, and headed for the house. I'll investigate the throttle linkage tomorrow. If the problem turns out to be the governor --on the inside-- I'm looking at a total dis-assembly of the motor, which means pulling it out of the tractor again and --what a mess!

Bottom Line: I wanted it to start, and it did; but it doesn't run right. Oh well.

 

[jchamberlin]

Update: I performed a static adjustment to the "governator," compared the linkage to the one on the OT M18 and it seemed to be oriented in the same direction, that is, decreasing and increasing the throttle moved the governor arm in the same direction, so I tried it again.

It was OK on the choke, but as soon as I released it, the RPMs headed for the moon again. I turn it off, checked everything, and tried it again, but this time moved the throttle to see if there was any reaction --there was. It would "idle" OK (still kinda high on the RPM), but then start to race if I moved the throttle anywhere near half-way (actually, quarter-way did the trick).

I experimented with the throttle and the governor arm, and determined (1) that the governor mechanism inside the engine was not working at all, at no RPM before self-destruction was the "governator" doing anything, there was no "tug" against the spring at all, and I know that is just not right; (2) the higher the RPMs the more (blue) smoke the engine produced. The smoke was actually more gray in color than anything, and given that I had done compression readings at an equal 90 psi per cylinder; I'm thinking the mixture may just be too rich. There was a strong odor of gasoline when I shut it down.

Needless to say, I'm disappointed.

Going forward, I think I'll do a Balance Test as there appears to be more smoke being generated by the cylinder on the right side of the engine (from the driver's seat), which is the one I haven't opened up. I'm just curious to see, before I open it up, if there is a marked difference in how each side performs.

I also thought I noticed a faint "slap" while turning the engine by hand when I was working on the flywheel; and after the engine warmed up, I thought I detected a slight knock. Since I learned a bitter lesson on the B&S 16 HP crapping out less than 10 hours after I re-worked it because I failed to check the bearings, I plan to mic everything, and especially the rod bearings using Plasti-Gauge (really neat tool).

Ugh! I really didn't want to be working on TWO engines this year, actually, counting the MG engine, I'll be working on three (3) --I'm looking at repairing an M18 (for the 782), a K321 (for the 149) and the 1600 CC motor in the MG.

Things really haven't been going my way lately.

I must not be living right.

 

[jchamberlin]

It keeps getting better & better: I just discovered that the carburetors on both my M18 motors are made by Walbro.

 

[jstertz]

Jeremiah--Sorry you're having one of "those" days!!! Sometimes it seems like we can't buy a step forward no matter how hard we try. Stick with it and sooner or later you'll get that thing up and purring like it should!!! Thanks for the detailed description and photos, I always appreciate reading your threads and keeping up with your projects. You'll get it!

 

[mgonitzke]

Before you write off the governor, re-set it as per the service manual and make sure the high-speed stop is in the proper place in the throttle linkage. 'Experimentation' is not the best way unless you know exactly how something works, and if you did, you probably wouldn't be needing to 'experiment' in the first place

 

[jchamberlin]

Matt: I adjusted the governor yesterday.

When the tractor is running, I'm not getting any tension on the spring whatever. According to the Service Manual, the flyweights should be putting pressure on the cross-shaft while the engine is running, and there is nothing happening at the cross shaft --NADA.

I'm going to run it again today, and try to get the carb adjusted. The carb was VERY loosely attached to the engine when I got it, and I'm wondering if adjustments were made to it in that condition, which would account for the apparently rich running condition.

I'll check the governor again, but I'm pretty sure I got it right; turn shaft clockwise, move arm away from carburetor, and tighten down.

 

[jchamberlin]

OK, I think I get it now.

It appears my emotional state can affect my ability to listen and comprehend instructions in technical matters.

Based on Matt's comment, I re-examined the linkage, and noticed that the "Full Throttle Stop" more than likely is not working, or rather, the throttle linkage has been run past it a good bit. The only thing stopping the the governor arm is the intake manifold itself.

Matt is correct, the "governator" may still be operational.

Please examine the photos below and tell me what you think. I think the the throttle "actuator" (for lack of a better word) needs to be moved to the other side of the throttle stop, because where it is, the throttle stop isn't stopping much of anything!

Also, if anyone knows the usual holes for the governor spring, please enlighten me. The spring is in the most worn hole at the governor end, but I'm not sure about the throttle end.

I may have answered my own question. If the wear scallop on the throttle "actuator" was caused by the spring, the only arrangement which would account for it is putting the throttle arm on the other side of the stop.

By-the-way, the motor started up and ran without smoking much at all today. The idle is kind of lopey, but I know the valve adjustment could be improved (I know, because I "over-adjusted" them myself

).

 

[mgonitzke]

That doesn't look like wear, that looks like chipped paint from here. That part is in the correct orientation.

 

[jchamberlin]

Thanks, Matt. I straightened the full throttle stop, verified that the linkage moved in concert with the throttle lever. When the throttle lever on the dash is fully slowed DOWN, the link it actuates is up against the intake manifold, and the link from governor arm is closing the carb throttle plate itself to the idle speed screw --as it is supposed to, see picture below:

When the throttle lever on the dash is fully speeded UP, the link it actuates is up against the full throttle stop as pictured below:

The problem I'm having is that not only does there not appear to be any tension on the spring (from the fly weights on the governor mechanism), but the throttle exhibits very little control. According to my Tiny Tach, and my ears, the engine is running 3000 RPM almost as soon as the linkage comes off the idle speed stop, and well before the throttle lever on the dash is moved to even the 1/4 throttle position, as seen below.

Again, there is no tension on the spring; I can manipulate the linkage back to the idle stop to slow it down, or compress the governor spring to make it run 4000 RPM with probably less than 1/8" of movement in the throttle arm. This manipulation was what I meant by "experimenting" in a previouw post, I'm not talking about adjusting the governor statically in any other way than stated in the manual.

In other words, I don't have to move the throttle very much to get maximum RPM (or better). So, I'm thinking that the problem is not that the throttle isn't positioned correctly, I'm thinking the problem is either that (1) the governor is not doing its job of attempting to close the throttle plate against the tension of the spring, or (2) the carburetor is "over performing" by letting the engine rev so high and so fast.

After I turned the motor off, I noticed oil smoke coming from #1 cylinder again, the cylinder on the right side of the engine when sitting on the tractor. I investigated a little further, and found oil weeping out of what appears to be three-cornered break in the aluminum front cover of the engine, just below where the governor is mounted.

I'm thinking that the governor destroyed itself when the motor was revved too high, or damaged in some other fashion. I've e-mailed the guy I bought it from for a more detailed "history," but I haven't heard back from him.

Man, it just keeps getting better with this engine.

(You can't hear the groan behind this smile.

)

 

[bpientka]

Sorry, you just can't catch a break on this.

Bernie

 

[jchamberlin]

Bernie: Thanks for the note of sympathy; but I blame myself, I should not have purchased a motor that wasn't running --never again.

I thought I paid too much for a tractor, just to get the motor, but then again, the motor worked and it looks like the $500 I spent on the OT tractor for the first motors pales in comparison to what it might cost me to get this second motor from an 1862 going!

 

[jstertz]

Jeremiah--that really stinks!!!

I keep hoping that this project will take a turn for the better but once again---another major set back! Jim D. mentioned something to me awhile back about a shaft working loose and backing out that holds the governor. When that happens it essentially explodes that whole mechanism! I wonder if that is what happened to yours...? He said that Kohler put out a service bulletin about cross drilling and putting a pin to retain it. Jim, if you are monitoring this thread could you post a picture or a diagram of this repair (preventative)? Or if Kraig or anyone else has a pic of it. I certainly don't want this to happen to my motor and I'm sure others running the M series engines would like to be spared the same fate. Jeremiah--Great point on hearing an engine run before buying it unless you just plan in the back of your mind for an overall. I guess otherwise its like playing Russian roulette. So what's the plan now?

 

[jchamberlin]

Josh: I'm not sure what I'll do.

First: I need to open the motor up to confirm what I think happened and see if the front cover can be repaired, or if it will have to be replaced.

Second: At the same time, I need to assess the internal wear and determine what an over-haul is going to run me.

Third: I'm going to have to think long and hard about my options.

At this point, I can foresee the following paths going forward:

1. Rebuild the motor, although this option will likely take money I don't have right now.

2. Swap the part I need into the OT M18 in order to cobble together a motor that can run the 4" PTO, that is, put the 1-1/8" crank into the Sears motor. But I'm thinking that this would require the front cover from the CC 1862 motor, the one that is broken. So, aside from the fact that I'm cannibalizing one motor to fix the other, I'm still going to have a "confuguliated" 782, even if it "looks right" from 10 feet away. For me, this would be a last resort.

3. Another option is to secure a PTO that is the proper diameter for the belt, but designed for a 1.0" diameter crank shaft and drop the OT motor back in. One reader of the "B-Belt / V-Belt" thread told me via an e-mail that he had been able to secure such a PTO from Briggs & Stratton. (I would think that the IH 582 came with a 4" PTO, but the crank was probably 1-1/8" too.) I haven't tried to verify his claim, but right now, this option is looking pretty good, at least for the immediate future. I'm going to check with my local B&S dealer who also happens to run the NAPA store.

4. Finally, I could just go back with what I started with, an OT M18 with the wrong diameter pulley. I'll just use the mule drive I customized and contact Charlie for a belt that will fit (I'm through with the local tractor supply stores). This option isn't my first choice, because I really wanted to finally "unconfuguliate" my 782, and the mowing deck was the last item on the list.

As a practical matter, I'm probably going to drop the OT motor back in for now --AFTER I secure some standard 0.469" spacers for the motor, which I understand are still available. Since I don't need a tractor for snow duty here in North Carolina, the only thing I expect to be doing is dragging a de-thatcher, an aerator, and a sprayer around the yard between now and the first cutting in the spring; I am not going to need a PTO of any kind until then. The motor in my 149 really needs attention, and I KNOW it is worn, it probably has the balance gears in it, the front axle, spindles, and steering gear all need to be rebuilt; the hydraulic lift piston needs to be replaced, and the tractor needs to be painted. So, I would rather put my limited funds into repairing it rather than sinking more money into the 782 right now.

I'm going to clean up the shed and clear my head before I do anything else.

Anyway, thanks for your interest in my situation. It helps me to know I'm not alone. In fact, the reason I use the forum is the camaraderie; even if we don't always agree, we share the same passion.

 

[kmcconaughey]

Jeremiah, my heart sank for you when I read of your set backs and saw the photo of the crack below the governor.

I don't believe I have a copy of the service bulletin that Joshua mentioned. I looked around in my archives but didn't find anything on it. Hopefully Jim will drop by with it.

 

[jchamberlin]

Kraig, thanks for the note.

We'll see what the front cover looks like on the inside when I open it up.

One of the issues I'm going to have trying to rebuild this motor is that I have no idea what its true spec number and serial number are. Any identifying information has been wiped off the ID tag, I'm left with only the serial number run of the tractors in the 1862 series, if the previous owner can be believed.

I'm not sure, but the previous owner may have procured the engine with a tractor in the state its in now --Kaput. I noticed he had a cyclops model in his driveway with a diesel engine in it that appeared to be retro-fitted; but again, I never had a chance to talk with him personally.

 

[jdiederichs]

Well, that certainly explains the sheared crankshaft key! I think that the internals may be saved if the governor assy did not wreck the timing gears. That hole could be fixed in the case with epoxy type adhesive sealer or welded back closed.

I hate to see anyone end up buying something that isn't represented fairly, sorry for your bad experience with that M-18. I sent the service bulletin directly to Kraig so he could find a way to post it. It is in regards to your exact problem. Good luck with repairs on that. By the way the I.D tag should read: M18S-24646 (spec)

 

[kmcconaughey]