KTM bottom ends?

[Kurlon]

So, while I'm watching all of my free cash and time get sucked away by my new house... I'm also getting really friggin anxious to race which right now isn't looking like it's going to happen for 2010...

My 520 is beyond just needing a rebuild, the poor engine should have given up awhile ago. The head needs a full rebuild, the clutch is shot (and I need to update the transmission), and I suspect my mains are gone.

I know what I want to do to the crank to adapt it for full SMR duty. That leaves me with a 2001 bottom end in need of LOTS of updates, and a head missing parts and needing some machining. I'm thinking if I can find a head and a bottom end in better shape than mine it might be easier than trying to spring for full rebuilds... any of the LRRS KTM nutters got spares they want to offload cheap? : )

[seth399]

will a newer setup (full motor) drop into your frame mounts? I am guessing probably not many years but worth a try maybe

[Kurlon]

Actually, as long as it's an RFS motor (single cam) they'll all drop in, newer engines will need a sleeve on the swingarm bolt, but that's a KTM part. My logic for going with a bottom end is there are updates that should be done for SMR use.

[seth399]

ah ok cool

[Tricky Mike]

My logic for going with a bottom end is there are updates that should be done for SMR use.

Can you elaborate if you have a moment?
I haven't torn down any '01 RFS's

[Kurlon]

Can you elaborate if you have a moment?
I haven't torn down any '01 RFS's

There are a few transmission updates that just need to be done in general on the old mills, shift detent arm, metal center case gasket instead of the old paper one, transmission is setup to push oil through the main shaft so it can lock out the clutch slave at WOT... upgrading the main shaft requires also upgrading the clutch hub/push rod/etc.

For SMR duty, weld the crank, convert to ball bearing mains, slipper clutch.

[Tricky Mike]

The trans stuff sounds expensive... Did they change that in 02? My 02 trans is stock and I've never seen those issues

How do you set the axial play on the crank if you ditch the roller bearings for balls? Is this a common mod?

[Kurlon]

The transmission setup was different every year up till 03 I think? That's why it's a PITA finding clutch packs and replacement clutches for early RFS motors.

http://ktmtalk.com/index.php?showtopic=367448 has a good breakdown of what changed and when.