Keymap/lmap and recursive mapping in vim

I'm using a keymap to type non-latin characters in vim. Like that: set keymap=russian-jcukenwin. E.g. that maps q to й 开发者_如何转开发and @ to ". The problem is that I can neither redefine/remove such mapping with lmap/lunmap nor define a recursive mapping, e.g. to map " to something else (and that breaks all mappings in vim-latexsuite and makes me sad).

The only idea I've got now is not to use keymap - and lmap all the keys manually.

So, is there any better workaround?