I was intriqued by this as l dont know the answer - a quick google revealed nothing apart from someone on TT asking about converting a 250 to a 300 and the comment back was that a 300 top end will fit on a 250 motor ..... hardly conclusive, but confirms the PCD is shared.

 

Hi Ship, thanks for your reply, unfortunately the fact that you can swap between the 250 and 300 cylinders just means that the crankcase bolt pattern is the same, not the cylinder head bolt pattern is the same.

 

But logic would dictate? Maybe not! @Pindie / @TQKTM might know as they have had the 250's ....... please post when you know, as its good to know.

 

I'll post up when I know, I guess if anyone has a 250 head kicking about I'd be grateful if you could measure the distance from the centre of one of the head bolt holes to the head bolt hole opposite, also if you could measure the overall diameter of the head that would be great!

On my 300 head the bolt hole centres are 95mm apart, the head is 105mm in diameter. (2007-2013 head)

 

My guess is that the difference will be how much material is removed from either head rather than different bolt patterns etc. It’d be much to expensive for KTM to have developed two cylinders and two heads specific to each cc model. My guess is just the bore changes along with head volumes but everything else is just the same.

 

I might have a 300 head, I think it's still on a bench somewhere round my mum's lol. It was a bit pebble dashed where the mains let go but if you're modifying it could be of use?

 

YES!

That is exactly what I need, a knackered head that I can machine so that it will work with head inserts. Please PM me if you have a head so that we can work out a deal.

Cheers for taking the time to post up on this thread.

 

If it's still in there you can have it! I'll keep you posted!

 

Cheers Dude but it is worth a few quid so I'll give you a few quid! (an incentive to find it!)

 

Sidecar..i have a tpi 250 head down the shed ,and a whole 250 tpi bike here at work ...now i can measure but this will be Anne measuring 2019 bikes

 

@sidecarbod what she means is that she measures with a stick, her mood, and the weather outside....

PSA out....

 

@sidecarbod what she means is that she measures with a stick, her mood, and the weather outside....

PSA out....

oi im not a witch

 

i dont think i can measure on the bike plug in the way..will look later at the head in the shed

 

Thanks for the offer of measuring the head but the TPI head is a different design compared to the older heads so its probably not worth the bother, thanks again though!

 

Ummm. Can you breathe when submerged into a village pond?

I mean you do use furlongs as a measurement standard.... Just sayin'

 

Pikers, points and ems - with the odd chain thrown in .......

 

dont you start ..you big bastard

 

Had a look in the shed and also asked dad to have a look in his garage, can't find it anywhere. I don't remember throwing it but may have, I'll have another look round there on the weekend. Did find a pair of rgv cylinder heads though lol.

 

I would have those RGV heads if I still had an RGV to put them on. What a bike!!!!

 

Still regret selling the rgv, I'll never have another at the price they go for now. Still, could be worse, my mate raced an rg500 in the 80s, a mk7 I think he said it was. Sold to fund the next bike. Need deep pockets for one of those now!

 

Good news, exactly where I thought it was lol. Let me know if it's any good to you and I'll either post to you or you can collect. Can't remember how far away you are.

 

Yeah that's just what I need! Thanks so much for digging it out. I'll collect it from you if that's OK, I don't live all that far from you and I'll bung you some money for the head. Please PM me with your address and a time an date that suits you.

 

Ooh I do love a good romance