Starter engagement issues

[spndncash]

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Picture.

to answer your original question I have not seen this - My 782 was approaching 2000 hours when the connecting rod decided it did not belong in the crankcase. My father bought it new. my mother mowed 15 acres with it for many years then I used it for 8 years on 4 acres until the engine went, with the original starter still working.
this is the breakdown of your starter

as I understand your issue -starter works fine when the engine is cold
But on hot restarts, the fully extended Bendix is no longer close enough to the flywheel to engage.

there is no room in the starter motor for the armature to move the amount you are seeing without hitting the stator.
to me this means:
1. the bendix is too loose on the armature shaft and it has gone catawampus. This would seem odd to be predicated by heat of the engine - the starter should be relatively independent of the engine heat so this lack of gear engagement should happen hot or cold
2. wrong starter this too seems like it would cause problems hot or cold. If it is the wrong starter the flywheel teeth look very nice for that to be the case.
3. not mounted securely or properly - this could be heat related but I would not expect it to self correct after the engine cools - unless the mounting is cracked - separating with heat and closing back up when cool. I would think this would be visible or possibly even cause a leak. but the starter is held on by ears cast into the block so this is possible.

with any diagnosis of equipment the best question is what was the last thing you did before this started happening? start there and see if that is the cause
I guess my next question is, are you buying rebuilt starters? - your shop should able to tell you if the starter gear to armature shaft have excessive play. there should be almost no play. Still I dont know why engine heat would impact this.
I dont know if this helped but I hope so.

 

[spndncash]

Mine duplicated as well.. not sure what happened there and this is why I dont drive a tesla! lol

 

[JPrattico]

oops looks like my post duplicated, bad internet and I clicked the post reply button twice

 

[exSW]

Does that make some sort of grinding noise when you put power to the starter? If there's that much slop in the gear then I would think that something would have to apply a light force to push the gear away from the ring gear on the flywheel. Thus, a grinding noise would indicate that the starter gear is slightly contacting the ring gear, and the ring gear is pushing the starter gear away from it preventing proper mesh of the gears.

I have certainly never seen this sort of issue with a starter before, worst I've had was a little pin break off the top of one, causing the gear to fly off the starter. Interesting part was that this was at a show. Managed to start the tractor once with a piece of paper clip acting as that pin, then searched the show's flea market and bought a replacement starter. Much better design (a roll pin and not a tiny flimsy clip) and still works on the machine to this day.

I'm very curious about what would cause this strange situation to arise.

It does make a grinding noise as it skips. Gets progressively worse untill they barely touch and flywheel remains stationary.

 

[JPrattico]

Makes sense, if there wasn't something to "push" the starter gear away from the ring gear the issue could not occur. Unfortunately I am clueless when it comes to the 82 series (especially starters, since I prefer my old Starter-generators) but it's clear that something isn't right.

 

[tkhoffman]

Let's go back to the begining, cause I'm lost. Is your original question that the starter is spinning even though the flywheel isn't? Yes I have seen this on other small engine starters. Actually my 782 had this issue. Richest would shoot out and engage perfectly. But if it was a cold day and maybe engine oil was thick, I could hear there's of the starter slow as the starter shaft slipped on this odd rubber piece attached to the gear. Your picture looks like you have one of these rubber type starters. When buying my replacement, the same part number will give you choices.. This rubber ended one and one that looks very different at the end of the shaft

 

[JPrattico]

The difference between starters you see is most likely that some come with the rubber cap on the end, and others without. I looked up Kohler m18 starters and that was what I saw, some starters had the rubber cap on the end and others didn't. The only other major difference I saw was color of the starter gear, some were a silver color and some were more of a brass color.

 

[mgonitzke]

Here is a measurement of the diameter of the bendix gear from a starter I removed from my 782.

9 teeth, ~1.14" gear diameter.

exSW, how does your malfunctioning one compare?

 

[gary noblit]

just a thought...if your teeth mesh approx. .050 deep ( I'm picking a number) what could possibly allow movement of that amount from heat expansion....nothing I know of ....and to miss the flywheel wouldn't it have to come up at an angle???

 

[gary noblit]

were there once upon a time a shim plate behind the mount ing ???

 

[exSW]

were there once upon a time a shim plate behind the mount ing ???

Nope.
I'm thinking sloppy tolerances in the aftermarket starter bendix.
Caliper batteries were a mite cold so I couldn't get a measurement.
I do have an old starter I pulled out of a 682. It's either IH or early CCC. I know I never had this problem with that 682.

 

[tkhoffman]

The difference between starters you see is most likely that some come with the rubber cap on the end, and others without. I looked up Kohler m18 starters and that was what I saw, some starters had the rubber cap on the end and others didn't. The only other major difference I saw was color of the starter gear, some were a silver color and some were more of a brass color.

No, it was more then just a cap. It was years ago but I remember looking at the bad starter and seeing that the gear was pressed over the rubber. It probably helped the engagement into the flywheel somehow but during snowplow season, the cold gave it enough slip to get me nuts. This rubber idea is exactly like the propellers on Mercury Outboard engines
The idea behind those propellers is that if you hit a rock, the blades will spin on that rubber hub before you damage parts of the engine. After hitting the rock, the prop would have to be rebuilt because anything above an idle and the blades would slip on the hub

 

[mgonitzke]

I'm thinking sloppy tolerances in the aftermarket starter bendix.

There is no way the tolerances are THAT bad. More likely the bendix gear is not the correct one.

 

[gary noblit]

Matt,we are missing something..3 starters later and he is still blaming the mfg ...I'm done

 

[bkattner]

Here's something maybe outside the box, but are the starter mounting castings both intact? I had a KT17 that broke one of them.

Crank bearings intact? I have a KT17 here that was running that I can wiggle the crank up and down, quite a bit, but probably not enough to give the issue you have.

My only other thought is I think you need to look elsewhere for your starters.

 

[bpientka]

Is there a chance the bolts are the wrong size? Would smaller bolts give enough play that the starter shift?

 

[mgonitzke]

Is there a chance the bolts are the wrong size? Would smaller bolts give enough play that the starter shift?

The bolts that hold it on are part of the starter. Can't really be wrong as they thread into the end cap on the starter. There is a feature on the engine case half that locates the starter properly.

 

[exSW]

Well,I robbed an original Cub Cadet starter off of a parts 682. No more problem.