640 main bearing failure......

**city2surf** · #1 15 Oct 2004

A sad story and a couple of questions...

Bought 640 2002 from Brackens, London, rode the bike to Australia last year (www.city2surf.c.uk) with the usual fun and games and an unexpected small-end bushing failure - was it me or something else?

Ignored all of the advice on this board and imported the bike. Took the bike offroad for the first time a couple of weeks ago, when the main bearing went. Fortunately I was able to find a shack to sleep in and got the bike to a dealer (Wisemans motorcycles) within a couple of days. KTM Austria have just approved warranty replacement of 95% of the engine. Bike was in warranty by one day.

I have a couple of questions someone may be able to answer:
What can cause a main bearing failure?
Everything is being replaced other than the crankshaft and the top of the cyclinder head. I have asked the mechanic to look at the valve seats, which are original and have 50,000km on them. Should I be thinking about anything else?

Still love the bike!

John

**Jerome** · #2 16 Oct 2004

Wow! Nice timing on the warranty claim.

- Some of the 2000´s had poor hardening on the main bearings so they disintegrated.

- I´ve seen a new 640 Adventure with only 50km on it in bits because the factory used the wrong size bearing in the balancer shaft.

Presumably yours has done 100,000km ish - you don´t say how many.

I´d suggest:

1 call Swampy (Mr 640 in the UK) on: 07855 464 922

2 have a look here http://www.ktmtalk.com and http://www.advrider.com

3 you´ve worn them out.

4 lack of lubrication - they´ll be a different colour.

waiting for new cam followers and camshaft in sao paulo......

------------------
Jerome

http://www.fowb.co.uk