When good bikes go bad

[green machine]

Who knows, need to do somthing with it...

True Steveo.....i don't envy you.....

[Dumruat]

I feel for you. no one likes to see a nice new bike blow up . the bore looked healthy prior to its mishap.

Would the old ktm 2 stroke have cost you as much to repair?


If you replace it instead of repair going back to a ring ding ding bike?

[flyingcr250]

I feel for you. no one likes to see a nice new bike blow up . the bore looked healthy prior to its mishap.

Would the old ktm 2 stroke have cost you as much to repair?


If you replace it instead of repair going back to a ring ding ding bike?

Yep ive never had any major problems with any of my 2strokes, so im going back to the trusty ktm 300...

[ktm84mxc]

If you lunched a KTM250/300 piston, barrel, head, conrod, mains the most you'd have to pay would be $2g NZ, you can buy a complete 300 kit in the states for US$700.
Cr are you buying new or 2nd hand? a mates got an 010 300Exc on trademe with a complete 250 top end as spares, bikes well set up for trail rides etc $9.5g. He bought a new 011 300Exc at just under cost from a dealer.

[flyingcr250]

If you lunched a KTM250/300 piston, barrel, head, conrod, mains the most you'd have to pay would be $2g NZ, you can buy a complete 300 kit in the states for US$700.
Cr are you buying new or 2nd hand? a mates got an 010 300Exc on trademe with a complete 250 top end as spares, bikes well set up for trail rides etc $9.5g. He bought a new 011 300Exc at just under cost from a dealer.

Yea going brand new again

[krad_nz]

Stink mate, thats pretty bad luck.

[cheese]

Could you turn it into a coffee table like top gear did?

Or is there an athena kit?

[yokel]

Sucks man!
Sell left over motor bits and transplant a 300 or even 380 2 stroke in the rolling chassis.


This is a classic case of why 4 strokes(mx type) are not that good of an idea for dirt bike.

[Latte]

There's a rebuilt cr500 motor on trademe ... just slap a ktm sticker on the side cover.

[pete-blen]

The head & cam maybe able to be saved..
I had that prob with a 74 XL250K1 years ago..
I line bored the head/rocker case & had the cam bearing
surface reground smaller.. Then fitted split race needle bearings...
Have also seen it done with white metal shells
on a Briggo Jawa speedway motor...
Datsan 120Y shells I think they were...

On the piston beval /round the piston skirt edge
so its less lightly to scrape the oil off the bore..

Figger out why you have low oil flow or preasure...

[CRF119]

Said to see! Put some pedals on it and sell it to a down hill mountain biker!

When i pulled my RMZ appart i thought, it was quite strange that the cam spun directly on the Alloy Head instead of being supported by a bearing, I thought it was quite cheap and rubbish. But It seems KTM do the same.

The CRFs run bearings in the heads i thought every manufacture would.

[CRF119]

Some options

http://www.ebay.com/itm/2008-KTM-450...item4602d2b23b

http://www.ebay.com/itm/KTM-450-SX-F...item46023a2580


My CRF450 is not worth selling because ive spent so much on suspension and setup so when the bottom end goes ill just be doing a CR500 conversion.

[flyingcr250]

Nope im done with 4strokes. I maintained it as sensibly as i could and it still went pop and no one can say why. Ill steal my forks, bars etc off it an put them on my new bike, one day down the track i might fix it if i havent sold it as a project...

[motor_mayhem]

Before you get ridiculously hasty I would just point out that similar things can happen to two strokes as well.

I have a 2 banger in my workshop right now (not mine though) that seems likely to need a new crank and probably a new piston as well.

And I have only just completed getting my 4 stroke through that.


Maybe an XR200/XR250 motor would go good in that KTM frame - could turn out vaguely similar to a freeride or something.

[jt119]

Before you get ridiculously hasty I would just point out that similar things can happen to two strokes as well.

I have a 2 banger in my workshop right now (not mine though) that seems likely to need a new crank and probably a new piston as well.

And I have only just completed getting my 4 stroke through that.


Maybe an XR200/XR250 motor would go good in that KTM frame - could turn out vaguely similar to a freeride or something.

XR200/XR250 to much power for him