If youre building up an engine can valves be exchanged between different engines? For example - can FZR600 valves be used in a 400 head or are they very different?

No they're different - Mang found this in his project.

oh well, it was worth asking

What's your bike like now and what are you looking to end up with ?

Evilchicken0 wrote:What's your bike like now and what are you looking to end up with ?

When I got the bike the clutch was seized, and whilst sorting that I noticed a bit of emulsion. If its not just due to condensation then I suspect the head gasket - though maybe theres another way for water to get into the oil?

If I do an engine strip down and find that the top end is knackered, Im trying to work out what my options are. I could do the 600 route, but Ive no guarantee that the replacement engine wont need a rebuild. And besides Id like to try the little 400 first When I used to commute on a FZR1000 it was a bit too easy to get into licence losing speeds...

Does the top end from an earlier (older) model 400 fit?

The head gasket is usually where oil and water collide. You could check the rad cap and see if there's any scum there. I think I'd finish the clutch warm the bike up and open the oil filler to try and get rid of any wat, then keep an eye on it, then if it gets worse your into doing the gasket.
Alternatively do the rebuild now although its a cost thing.

The 1WG head doesn't have the engine mounts on it

Cheers, so if its worst case scenario and I need to replace all the valves, I guess its OEM Yamaha only?
Any idea of prices or part numbers?

Here you go;
http://www.ebay.co.uk/itm/YAMAHA-FZR400 ... 186wt_1218

Don't forget Import duty and V.a.t will be applied by customs if importing to UK

They will be £435.00 to the door i recon.

hunter wrote:They will be £435.00 to the door i recon.

Jesus! Who makes valves and valve seats? Im wondering if an alternative can be sourced...