dt200lc 37f engine in 125lc

[yamyzee]

Hi folks anyone ever seen/ridden/built a dt200lc ypvs 37f engined dt/rd125lc? I have one here but have decided to use an overbored short stroke 203cc autisa kit on a 125 engine i am building.autisa claimed 27.9 bhp for their 175(171cc in reality on a 66mm bore) kit on a standard carb.this one will be running a 36mm mikuni and a 72mm piston so considerably more.yamaha claimed 32(?) bhp for the 57x66mm 200cc 37f ypvs engine on a small 28mm carb.the guy i bought the 200 ypvs engine from ran it in a mk1 rd125lc with the powervalve pegged open and reckoned it flew!would love to here any comments from anyones experience.thanks.

[cinder]

What's the 72mm piston from ? Dt250 ?

[yamyzee]

No chap.you can use a dt250mx piston but you have to have"top hats" made for the gudgen pin.

[yamyzee]

Send me your f#cked autisa cylinder and £250 and i will send you back a 203cc,(205cc on the ypvs bottom end) kit,bored out with a 72mm piston kit and new copper head gasket which can be rebored a further 4 times.bargain....

[cinder]

What piston are you using ?