What have you got in the hole at the moment...

 

They are different lengths to suit the crank diameter.
But like CTD says, whats in there now? It's an allen screw with 6mm head, ground to a point at the end.

 

oh yes there is with a thick washer/spacer is this the locking bolt or is this in there to plug up the hole (sry novice over here)

 

Novice.. locking the crank.. plug up the hole.. step away from the machine!

 

That's the bolt. Remove washer and screw in by hand when you can see the slot in the crank

 

^^

thanks for the replies, sry for the late reply,

the bikes got quite a few oil leaks,

the drain plug, bottom oil screen and the crank breather hose
the bike is quite wet near the hose and there is oil in the airbox

does this mean the piston is on its way out?

 

More than likely the oil ring gap will be massive. Change the piston.

 

Could I get away with just doing the piston rings?

 

If the black pads on the piston are not worn away and you promise not to go exploring the rev limiter - yes!

 

So where can I get any reasonably priced piston kits from

Also could the valves being out of spec be the cause aswell

Oil drops from the carb too so I guess this is not normal

 

It will be the rings.
Take it apart and check the condition of the piston.

Change the valve stem seals while it's apart and check the inlet valves for sharp edges.

 

never worked on a rfs engine before and have watched quite a few vids but is it possible to reuse the chain rivet link for the cam chain or should i buy another one,

also i should prob get new gaskets for the top end but cant find any that are not too expensive
i found this but it says its for an sxf so dont know if it will fit
https://motocrosspartsuk.com/mdr-top-gasket-set-only-ktm-sxf-450-03-06/

 

Buy just the gaskets you need from a KTM dealer. Others are shite (apart from Cometic)

All you need is a head, base and waterpump gasket. You can use a Motion Pro or similar chain tool if you are careful.

 

there are three different cylinder head gaskets

59030036000 CYLINDER HEAD GASKET 95,3 MM
59530036000 CYLINDER HEAD GASKET 89,3 MM
59830036000 CYLINDER HEAD GASKET D=75 02

i think its the second one right?


EDIT: The engine is kind of getting hard to start and doesnt idle very well once choke is turned off but once it is fully warmed up it seems to start easier