2000 kdx 220 losing power

Props to those who can weld aluminum! I have had decent luck with the aluma-weld stuff, but never had the nerve (nor the TIG) to do aluminum. In theory I can do it with my oxy-act setup... but I don't have the knowledge or experience (and maybe not the skill).

Especially cast aluminium, i hear it's quite a task! I just had a crack in my 200's case welded up...