Stator eating engine?

[brylon644]

Replaced the motor on 93 750sx small pin. Got it all in over the past weekend, was firing and running with gas poured down the carb. It was making a grinding sound when you hit the start button... figured it was the bendix being stuck a little. Buttoned everything up today and went to start it. Not firing at all and found zero spark! Pulled the cover and found that the stator was chewed up on the outside. Guess it wasn't the bendix that was making the noise! This is what it looked like
I also found these wedged in behind the flywheel and bottom of the cases. Any idea where these came from? .

Also any ideas on why this happened would be great. I have my old motor to look at and measure from. The measurements look to be ok

 

[snowxr]

Those look like locator pins from the case cover/ crank case. Must have been loose, and stuck to the flywheel magnets before assembly. That'll chew up a stator.

 

[brylon644]

Forgot to mention... they aren't locator pins. Length wise they are shorter

 

[Pro-pulsion]

The windings look to be melted. The only experience I have seen relating to that is bad crank bearings. If the crank bearings allow the crank to throw out of center the stator will make contact to the flywheel, where there is friction, there is heat.

 

[brylon644]

The windings look to be melted. The only experience I have seen relating to that is bad crank bearings. If the crank bearings allow the crank to throw out of center the stator will make contact to the flywheel, where there is friction, there is heat.

Crank seems fine as far as I can tell. Thought along those lines when I pulled the cover offer and found stator chewed

 

[brylon644]

Can anyone tell me if the bendix has those metal dowels inside of them for bearings? If they came from inside that would explain a lot

 

[Pro-pulsion]

When the crank bearings went in one of my old skis you couldn't tell by trying to lift up on it by the hand. It was only under power that the crank would throw out of center. For me, one symptom I noticed was hard starting and what seemed to be hitting the rev limiter when really it was a lean stutter from air entering at the crank seals as a gap would open during the throw out from the bad bearings. It may not be the situation for you but just something to keep in mind if you have never touched the crank. The ski doesn't have to be old to have bad bearings either, there are many variables that could relate to bad bearings. Just saying is all. I tend to agree on those pins looking like location dowels, possibly they are not short as you mentioned but rather are meant to be installed on the flywheel cover rather than in the cases or the other way around. Most of the time the holes will be deeper than the dowel pins are long to prevent them from punching through the cover or cases when torqued down.

 

[brylon644]

When the crank bearings went in one of my old skis you couldn't tell by trying to lift up on it by the hand. It was only under power that the crank would throw out of center. For me, one symptom I noticed was hard starting and what seemed to be hitting the rev limiter when really it was a lean stutter from air entering at the crank seals as a gap would open during the throw out from the bad bearings. It may not be the situation for you but just something to keep in mind if you have never touched the crank. The ski doesn't have to be old to have bad bearings either, there are many variables that could relate to bad bearings. Just saying is all. I tend to agree on those pins looking like location dowels, possibly they are not short as you mentioned but rather are meant to be installed on the flywheel cover rather than in the cases or the other way around. Most of the time the holes will be deeper than the dowel pins are long to prevent them from punching through the cover or cases when torqued down.

I should have it figured out by next week... taking it to a better mechanic than me. Will keep you updated if its the bearings. I'm leaning toward the dowels being the culprit at this point. They weren't in there when I started putting this thing together. Just have to figure out if they came from the bendix or the guy I bought the motor from.

 

[badvinny]

Looks like they may have fallen out the first time you opened it up, they may have magnetically stuck to the flywheel, and then done the damage when you started it. I looked and didn't see the dowels in your first picture.

 

[brylon644]

Top one = 3 I found inside the flywheel
Bottom = Flywheel cover pins

 

[brylon644]

With One of those pinned up against the flywheel and engine case, could that have pushed the flywheel out of perfect rotation. Resulting in the chewed up stator?