URGENT! Engine parts needed for Husky WR400 1984ish

[NordieBoy]

Out on a laidback enduro yesterday and a mate's engine went clunk!

He's not too happy at the moment as he had just got it going and it was going very nicely - until the last lap.

Just in front of the chain sprocket the case has split and moved back about 5mm.
Poss broken tooth between 2 cogs?
Anyone know of parts for these engine cases/gears as he was going to race it in the North v South Vintage MX this weekend and if he can't get it going he may be forced to treat us to his mad skillz on an XR200 instead.

That's 2 bikes my XR has pulled out of the forestry now

[Gregs_4]

Hi.This is a long time after your post but I have a 85wr400 that has seized badly .Parts are hard to get and v.exp when found as i'm sure you know.Maybe one of us could make a good motor out of two?.......