It isn't so much taking off material as it is smoothing the factory rough edges. Some will tell you to "sharpen the sprocket teeth". That isn't necessary. The rough edges are what causes problems sometimes. Run your fingers over the teeth of the sprocket and you'll feel the rough edges. That's what needs to be removed.
As opposed to grinding I like to use a wire brush wheel on a bench grinder. That will smooth the teeth so they engage the chain more easily then make sure to keep the chain lubricated.
That's one man's opinion. You'll get others.
Tom
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I have maybe a similar problem, but accessing the sprockets I have is not a problem.
FB, maybe you can get Allen Wrench Type Drive Bolts that could work instead of hex heads. I find that I try replacing all the hex heads in hopes it is a better way to fasten and unfasten without rounding off the heads. I have had to use Easy Outs, Super Outs, Bolt Outs... to remove rounded off stuff and it is better to avoid needing to do that. I realize that you got it that way, so I hope you get parts removed OK.
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What I am dealing with again:
I have a couple of sprockets that have sort of a squared off rather than more pointed ends and they are all for #35 chain.
The newest one I had quite a time getting the chain not to make popping sounds as I turned it manually with my hand. I finally got the two jack shafts at the right spacing apart for the tension and as best both parallel.
I did not hear nor feel it making and scraping or popping sound and tried it with the engine powered slowly and then full bore trail riding.
I had to remove one of the jack shafts temporarily when I put a new oil breather on the near by engine.
When I tried lining up the jack shafts to be parallel again I got it so it barely makes and clicks as the chain goes around.
I am thinking of trying the wire brush on the large sprocket that has the more squared off larger width teeth in hopes that I need not go back and keep trying over and over getting the jack shafts alignment again.
The more pointed tooth sprockets I have I did not have this problem so I think I should try this wire brush on this particular sprocket lightly and see if it helps.
MT
PS the first picture of the two sprockets held adjacent to one another and that are of the exact same number of teeth, are just to show how same number of teeth and both #35 type can look different, the shape of the teeth.
The second picture is my new sprocket 28 tooth, that I almost felt I would have better liked it in the smaller width tooth type, but it is what I bought and already used successfully on miles of trails.
The third picture has the lower sprocket being a wider width tooth type that the upper sprocket as you see how it is with chain on both sprockets.