Rather than clean them with sandpaper, use a good contact cleaner. The terminals have a fine plating on them the help resist corrosion (remember, even the newest NSRs are still 15 years old now, and the latest MC21 is 20 years old, and have often spent quite a lot of time exposed to the elements!) so scratching it off will only promote faster corrosion in the future.

Clean the terminals up and give them a little squeeze to tighten them up.

It sounds to me like it could be the reg/rec. You should put a volt meter across the battery and check the output on idle and throughout the rev range. It should remain constant at around about 14.2V.

There is a fault-finding chart in the Workshop section, and also numerous posts about checking the reg/rec and poor connections all over the forum across the last few years if you do a search.
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Andy.
NSR-WORLD.COM

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