Petrol engines starter bush removal

any ideas on the best way of removng the starter motor bush on 2lt air cooled? Have tried using an expanding bolt. What size tap do I need?

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size M12

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Use a tap ie from a tap and die set, i think its half inch or 13mm this will cut a thread in the copper bush and gradually twist it out, worked for me before. Soak the new bush in oil overnight. Then use a bolt with a nut screwed a little way down and tap it in with a soft hammer, make sure it goes ins traight at the start. Buy two bushes so that if your first attempt goes wrong you have a second chance and can learn from the first attempt, they are cheap