"My brother's BF100 is sim
"My brother's BF100 is similarly leaking oil (due to a clogged cooling system and subsequent overheating.) A mechanic told us he needs to replace the gaskets. Unfortunately, Honda no longer supplies these but he will install them if we can find them. A possible problem for both of us*: I searched the web for several hours trying to find after-market gaskets. So far I have come up with a big zero. If I find some, though, I'll let you know. If you or some other reader find out where these can be purchased, I would appreciate it very much if you would let me know. Thanks and good luck.
* You might look at one of the threads above which indicates that merely cleaning the carbs may correct this. We haven't tried that yet -- but I'll let you know if it works."