Hey guys im new to the forum, i just got a fzr 400 1990, very cool bike. My first questions is im finding that here is the states that you cannot find pistons for the 400 , stock, or oversize, so what in the world do u do if you want to rebuild the engine ?.

There are 2 different size rings sets available here, first over, and 2nd over size, but with no pistons to go with them what good are they ?. So are there any pistons in the UK available ? thanks.

Mike

First thing's first ... which model FZR400 do you have ??? Look here http://www.madsi.co.uk/models.aspx to find out.

Not everbody rebuilds the engine a lot of us will just look for a seconhand one first. If the barrels are badly worn then it's probably better to go down this route.
Next up is the 600 engine conversion it's more or less stick it in twist it and then jiggle it, but if you have eveything to hand you might be able to do it in a weekend.
You could build a 600 top end onto the 400 too this gives 560 cc with a shorter stroke than the 600.
I don't know if the 600 pistons would go into the 400 with any ease.
New Yamaha pistons will cost a bit of dosh though, so be very sure that's what you want to do.

I have 1990 fzr 400A, its the US version of the bike. I thought about doing the 600cc swap but decided i dont want to do it. I did find some oversize pistons at a place in the UK the guy just emailed me back today and says he has them in stock for $60 usd per piston, im assuming they fit my bike, im guessing the different 400s have same cylinders ? i dont think it should be a problem, i did mention to him that its a US version of the bike.