ORIGINAL: gaRCfield
ORIGINAL: da Rock
Sometimes the rubbing you see on the inside of the backplate happened when you jammed your electric starter against the spinner and hit the switch.
Don't worry about it.
Depending on the windage of the drive washer, some engines will give the drive shaft enough slack to get the crank pin back to the backplate. Some engines have drive washer dimensions to keep that crank pin off the backplate. Some engines have thrust washers behind the drive washer that're there for that purpose. If you have lost that trust washer, that is if your engine uses one, there could be a problem. But as you've seen, it isn't a big one.
Does the engine seem harder to turn over with your electric starter? Does it seem to bind when you slowly turn it over by hand? We don't usually push in too hard when turning by hand.
When running with a prop on the shaft, that shaft is not going to be pushing against the backplate.
If you're not seeing any problems, check back after awhile and see if the marking has increased.
It's on the sides of the crank case, not on the back plate.
lol..........
I was looking at a similar thread some hours before jumping into this one. They had an excellent picture of the backplate, btw. When I jumped, I thought I was in that one. Should have noticed the picture was "gone."
Not the first time I've sounded off on the wrong topic.....