@oldman Any help is amazing bro! will see how it is tomorrow and go over some of this stuff

My wr200cc/dt125r hybrid engine runs with lid cut off. I ran it also with the 125 engine. You just need to jet accordingly.

@ninja As a general rule of thumb, the greater the compression ratio the lower torque spread but the greater the peak power. I don't know the figures, but I'd look to go with a domed head.

All depends why reboring it, if the cylinder measures size you say then never been rebored. The cylinder on your year although called 56mm is actualy 55.95mm, if the cylinder is not damaged then just get it honed. If honing the cylinder then this piston is what you need.
https://www.ebay.co.uk/itm/Yamaha-DTR125-DT125-R-DTR-125-56-25mm-Bore-Namura-Piston-Kit/292513505226?hash=item441b29dfca:g:jyEAAOSwwbdWQwnA

Whatever size piston you buy whoever is reboring it will bore and hone to match what piston you supply. The best reboring is done by Karl at KPM as had them do a
few and also by PJME. Karl charges £30 for a bore and hone with return postage at £10-16 postage depending on courier and insurance required.
He will also fully port your cylinder for £100, just have to tell him what your after like more midrange etc or more mid and topend like a YZ.
http://www.kpmotosolutions.com/

The DT has now undergone a kickstart conversion! Feels so cool!

@sgt-robuck-5 doesn't work like that. Air pushes coolant up in the expansion tank filling it and then spits out on the road. Then returns to normal once cool. Just open the radiator cap and bleed it, problem solved.

@irongamer727 I’d say so yes

Aww cool, it's a belgarda engine.

Italian import, you get mega props for owning one. They have wicked Motori Minerelli Stamps where the original DTR engine doesn't. It's super cool engine.

Slow as balls though. It's just not comparable to the SP.

@calum That’s pretty cool might have ya have a check some day

@irongamer727 The stock Pilot Jet is (25) , My advice is to try (27.5) to support your mods.

Also dont forget about Needle height! Very important aswell

That will also do

alt text

The clutch cover gasket doesn't need to be anything special.

@irongamer727 for what bud?

Right also, don't be so quick to slate Yamaha for using the bolts that they did.

I'm not going into here, you can easily Google that information, but trust me when I say there is a perfectly justifiable reason as to why they used the bolts that they did.

@gilera-sc you have the best of knowledge right here on this forum

Mine slipped with Castrol Magentec. I just use Castrol GTX Semi 5-30w

I've always done about 5 heat cycles then a gentle ish ride before riding normal, never had any of my rebuilds seize or fail, obviously you don't wanna be holding it wide open for 2 or 3 rides but don't be afraid to accelerate, with a good forged piston and a few heat cycles you won't cause any harm.

Used 10w40 gear oil in mine with no issues, did replace clutch in 89 and suspect original plates contaminated as very "sticky" when I got them out

Took it into my college to ask my tutor what he thinks. (he builds race bikes) he said it looks fine and I could file it down very lightly. he also said the scratches on the outside were fine.

:grinning_face: :smiling_face_with_open_mouth: :smiling_face_with_open_mouth_smiling_eyes: :grinning_face_with_smiling_eyes: :smiling_face_with_open_mouth_closed_eyes: :face_with_tears_of_joy: 🤣 🤣