Yeah, a closed void would be subject to repeated heating and cooling stress. It’s also really handy for helping get the cases split I remember that I crapped myself when I first found it. I covered it with sealant

Typically what are you gaining on a two stroke with engine braking... It's not like a four stroke. When down shifting I always blip the throttle, to both rev match and maybe give it a squirt of oil. I certainly wouldn't be going down a big hill engine braking the whole way at high rpm on a two stroke. Nice blips on the throttle and a high gear to keep the RPMs down. When it comes to competition bikes, well reliability is all out the question and if engine braking does even a fraction of slowing down then it's worth it, but for road going use I only engine brake in an emergency.

I crawled around the bike today trying to locate where the clatter came from, paying extra attention to the powervalve cap. Holding a screwdriver against various covers to feel vibrations. I am far from certain, but I think it is the water pump, actually. I might disassemble that and have a look later this week. Thank you both for the input!

@somerandomguy314 Really? I am sure that's not the case, I sell to EU all the time through eBay's Global Shipping Programme. Ask the seller if they'd enable it, it's invisible to them and they just ship it to a UK Warehouse.

@Bilbo9000 Outstanding, I never thought of doing that! Well done Sir

@Sgt-Robuck-5, I have the same scratches but there is also metal in my oil, do you think the metal could be frome the scratches on basket or my transmission?

You'll want to understand why that's happened before restarting the bike. Lack of oil, incorrect piston ring end gap tolerance, or just generally tired engine, etc.

For you guys in the UK: https://www.gpxmotouk.com/shop-gpx.html They have the parts to convert the DTR to 230cc, can probably get the complete engine too. If I was thinking of a engine rebuild and/or Athena 170, I would go for this instead, based on what I learned from the Athena 170 kit.

Cheers buddy, I'd searched and just turned up gibberish that confused me even more, but once I ignored all the threads claiming the pulley rotates clockwise for PV opening, and set the cables back as they were supposed to be (1-2, 2-1) it all made sense again - it must turn anticlockwise viewed from the LHS to open it couldn't work the other way! Anyhow, it's all up and running and I've fully re-dressed her and given her a wipe over and a run up and down the road. All seems well enough but it feels like the PV opened more and earlier before I tore it down and serviced it, I think it had been adjusted from the normal peg-in-hole alignment perhaps, but it's al good enough for now and if I want to tune it a bit differently for preference at least I know what I'm doing now! Time to ride it some more whilst I think about sorting my carb tune properly down the line. Cheers Calum!

Thanks Calum.

@Calum thank you so much

Apart from oil leaking from engine block, the engine runs good when it runs.

Oh is it? I did wonder as it has a tread can’t remember was awhile since I took it out. I was thinking it could be blank cheers mate.

Moral of the story from this I can see is More horse power = power maintenance worm with pustion changes probably more regularly Keeping the dep exhaust carbon reeds and sprocket changes seems like the best for performance with out risking blowing pistons more frequently I did see a video on YouTube on how to make two stroked more powerful but with this there was a risk of blowing the engine maybe if you want a fast bike just get a bigger one? I wanted a yz road legal but for daily use I can imagine these get warm and aren't really good for road bikes sure for the track for a couple hours it's all good The dtr is a true work horse in my opinion

Done. Thanks guys