It depends which series you have. The first Lamune 
Series is : NG Knight Lamune and 40. It was 
produced in the late 80's and consists of 39 
episodes (give or take 2). It spawned 2 OAV series 
of 3 episodes each, EX and DX. Then in the late 
90's a new series was released. It is called VS 
Knight Lamune & 40 FIRE!!. Fire has 24-26 
episodes. It also has a OAV series called VS 
Knight Laumune & 40 Fresh (It's english name is 
Knights of Ramune) which is filled with horrible 
fanservice (not good fanservice mind you).

It sounds like you have the VS series, which 
features two girls Cacao and Parfe helping out 3rd 
Gen Lamuness aided by old school 'hero' Da Cider. 
There were two baddies chasing them around as well 
Dandie and Pheromone.  Does this sound right?

If not they you might just have the orginal or one 
of the OAV series.