[Dupo]

Well if your pipes can slip on to 1 5/8" .. and your pipes wont stick out too far (they look long) ... then id cut at the 1 5/8" and just slip them on and tighten down. No need for a reducer then.

Just make sure your pipes arent too long if you mount them there.

Other than that, it looks like you got a "Marauder" gz250 for over seas and is different from ours in the US. You may just have to figure out for yourself how you are going to mount them.