hi all im new here, im restoring a DTR 125 for my son the bike is a 1992 dtr that has a fixed power valve,

i was wondering if i change it to a servo one would it help with lower revs and if so how do i go about it

On a 92 you have all the low rpm power your going to get. The power valve cleans up the middle and then gives the power it's designed for at higher revs.

Not having the servo is a restriction. The full power stuff in 92 had around 24 hp

Finding the electronics will be the tricky part. Tying them up with the correct servo.

thanks for that what parts will i need

The problem is 2fold.

1 The parts were rare in 92, you may be able to use tzr125 cdi and servo controller with the servo and cabling.

2 The bigger issue. A full fat dt125 is above a learner licence. As a full power bike its even above the restricted licence limit due to power to weight ratio.

The good news is a 92 bike in good health with a good pipe is no slouch. Certainly quicker than all the modern stuff as its a quick bike thats been detuned.

What was done back then by me and some others was to get the cable fittings for the powervalve and use a choke cable (remember them) on the bars to swap between high rpm power and low. Thats just as illegal as the pv servo though.lol

The later DTR's were designed to make learner levels of go from the outset. Thats why they cant get them to go like the old ones. As well as the de restricting madness. Modern 125's aren't restricted. So your tuning them. Very different.

all done, manage to find a 3 wire servo on ebay,plugged straight into the loom and with the pulleys and seals from yambits was easy

a lot easier to ride