Yes they are diffrent! I brough the dt125r 99 ypvs from a lad that had just put in a new jesil race crank in and sold it to me as just needs new head gasket, so popped one in and bang it went! i then groved a ring around the bore of the head and poped a Heat rated orange o ring in with this heat rated glue stuff! It worked i then put and standard exhaust in down jetted from 240 to 210, not long after it blows up 4 miles from home 2300 long walk home, so i brough a copper gasket same again. 2 base gaskets (lowers the compression) ive read on here? Same as then saw this and checked mine 3mb00 barrell and 3mb head, looked on ebay to see if yama sold a 3mb head and it is very diffrent! like is Has got an little adge around the bore giving better hold of the compression than a 3bn that is complely flat, my question is can i still use my copper gasket or go for the standard one what also has the imprint of the little adge around the bore? And a thank you i wouldnt have figured it out without this page!!!

@AlfieHopkins These any good bud; http://www.ebay.co.uk/itm/Yamaha-DT-125-R-Spring-spacers-Stainless-steel-V2A-New-Tuning-DT125R-Jack-up-kit-/191501575986?hash=item2c96622732:g:YFwAAOSw~FNUYzpu

Sick, these are all the right ideas! Looking forward to this one man

Hi there Tommy. By Valving fine I presume you mean the powervalve, since there are no valves in a two stroke engine. What years your DT? How is the condition of the battery? Does the valve do the cleaning cycle upon turning the ignition on and off. What condition is the engine in? Miles travelled etc. Have you tried pinning the powervalve to see if that rectifies the revving issue?