I am starting to build myself a flat tracker, i have a 3en2 fzr400 frame with a 3tj rear shock, i'm not sure what the forks are from because they have 42mm stanchions which aren't standard. Firstly i'm trying to find a bottom yoke to fit, but not knowing what bike their from is proving to be a headache, any help will be greatly received. Secondly does anyone know what engines will fit, i know an fzr600 will but would like to go bigger if poss.

normally flat trackers are twins/singles but if that floats ya boat, go for it.

42mm stanchions? could be anything

your right, 42 forks could be from a number of bikes...any photos? that'd prob help?

thanks for your replys peeps. I have measured the stanchions properly using a vernier and they are actually 41mm, anyone have any further idea's!

As regards to which engine to use, i want to use a fairly modern four cylinder engine for the extra power and reliability it'll give, would like to get a tz750 2-stroke engine but havent got several grand at my disposal :-)

You could try dropping in to customfighters.com, I remember seeing a thread in there about forks - like, a big list of bikes listed by fork size. Might be an easy way to locate a yoke that'll fit that way.