Idea's on what engines will fit in the fzs600 (2001)

[Lumpy]

Thundercat engine won't fit for a host of reasons, mainly because it has downdraft carbs (airbox is above the engine, not behind it as per the Fazer 600). Many internals are similar to the Fazer but the engine casings are different to accommodate the different Deltabox / Steel cradle frames.

TC engine would fit with Fazer CCT and casings and using the Fazer carbs etc. No bloody point though and no way with the thou fit.