Posted: Thu Jul 26, 2007 8:50 am
I have to say that my Bongo sounds and feels better with new oil in. I think it is hard on oil and regular changes are a 'good thing', even if some oils may cope with longer intervals better than others. 
A forum for Bongo fans and owners
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https://www.igmaynard.co.uk/bongo/forum/viewtopic.php?t=12961