hello people,

This is my first ever post on any motorcycle forum, i am hoping someone out there might be able to help me with a problem i'm having with my 2003 DT 125 that i just bought on the 1st of august, i am trying to deresrict the bike. I have taken the restrictor out of the exhaust, but i'm not sure if the power valve is working properly because when i hit 6000-7000rpm the bike stops revving! My bike has the servo fitted and it moves when i switch the bike on but the last DT i had flew when i hit the dreaded 6000rpm but this one wont budge at all this makes me think it is NOT working while i am riding . Now I have read a few posts on here about earthing a wire which im pretty sure has not been done on my bike because it'll only do a top speed of around 60mph and when i picked the bike up the only modification was a dep end can but the front pipe was still restricted , please please please if there is anyone out there who has done this to there bike could you tell me a step by step on where the wire is how to set the powervalve properly i know this bike is a beast at heart and needs to be unleashed!

Thanks very much

maybe you should get a bigger main jet as well? could be starved for fuel past 6k rpms with those modifications.

hi thanks for the reply checked my plug this morning (nice and chocolatey) , do you know which wire i need to earth from behind the speedo?

hi thanks for the reply checked my plug this morning (nice and chocolatey) , do you know which wire i need to earth from behind the speedo?

hey i have the wiring diagrams for few dts and tzrs and full haynes manual in pdf format i could attach them to an email if they would be any help ?

Hi could you also email me a hanes please im struggling with my carb its a 2003 dtr 125 thanks v much [email protected]

see here http://www.yamahaclub.com/forums/index.php?showtopic=18186

I had a TZR without the servo, I just removed the locking pin from the valve turned it though 90 degrees and locked it in place.

Standard sprockets it was gutless until that 6K but reached 105mph, on the track...

I didnt do anything to the carb or wiring just opened the valve.

I guess the DT will have different sprockets n maybe different jet sizes.

Rev Limiter De-Restriction

Going into the speedo is a four pin connecting block. There are 4 wires going into the block and only 3 wires coming out the speedo side. Just find the Green & Black wire going into the block, clip it to separate it from the block, and strip the end and join a small piece of wire to it (long enough to to join to an earth on the frame). When the Green/Black wire is earthed to the frame this stops the YPVS from retarding over 7000 RPM. The engine should rev freely now.

Can follow this post but my speedo has 4wires in an 4 out and they are red, blue, black, and black/white on both sides of the block???