Sorry to hear about the mechancial trouble. Hope it can all be figured out.
For big bike help in Luanda, there are a few individual owners, but I found that they almost all imported their bikes and dealt with their spares themselves. There are two dealers that I found, a Suzuki auto dealer with a sideline motorcycle delership (no spare parts) and as of last year, a KTM dealer. The KTM dealer has probably the best mechanic in the city as he is Portuguese I believe and received his training somehwhere in Europe. He may not be able to help you with your specific issues, but as a guy to help you troubleshoot probably the best option. GPS co-ordinates I don't have on me, but you sounds like you have met the local bike club members and they will be able to put you onto them. If you can't contact the members on a timely basis, I'd get a taxi to take you to the Suzuki auto dealer near downtown, and the guy there is a member of the club and will give you directions or take you to the KTM dealer.