Oh yeah you'll notice a massive difference. Improved power low down and in the midrange. 

Right so will keep fault finding as it could be a faulty cdi unit, will report back when it's sorted and I find and fix fault.

does it say anything in the workshop manual about testing the servo?

You can pin the power valve open till you get a new servo will loose a little bottom end power but will have full power up top end 

Thanks Chalkey for pic, I put power direct to servo motor from Battery and nothing happened so thinking that motor is duff, i may have to pin it as per pic till I get new unit, i take it the slot and hole line up for full power position.

Thanks Chalkey for pic, I put power direct to servo motor from Battery and nothing happened so thinking that motor is duff, i may have to pin it as per pic till I get new unit, i take it the slot and hole line up for full power position.

yes that's right, what shape is the end of the pv though, either diamond or rectangular with two curved sides?

Rectangular with 2 curved sides Airhead.

Rectangular with 2 curved sides Airhead.

right well like you said thennIt will be fully open with the U of the pulley and the blind hole in alignment...unless of course it is 180 degrees out of position, in which case it will run rough!  If it goes like stink it will be right, if it doesn't you better take off the exhaust and make sure the top of the port has a smooth flat surface all the way through the pv to the bore of the cylinder

They are supposed to yes but I would remove the expansion chamber and put a finger in the exhaust port to make sure the power valve is in the right position ie smooth to the port as some times they can be 180° out 

Well pinned it open and boy does she rev now when riding 9000 rpm plus, but had to laugh as it is all hills here so she really struggled up the hills so going to adjust pinning position, have ordered a 2nd hand servo motor off Ebay so all should be good can definetly see why you need adjustble servo for better overall performance.

Oh while looking around found a company in Europe found a company called zeeltronic who do programable CDi units to improve performance so you fit CDi unit then use a handheld programer to fine tune bike not cheap about 250 GBP and lets face it on a 125 cc bike its not like there is a whole of power hidden waiting to be unleased but on bigger bikes could be usefull.

will get back to everyone when New servo Fitted, Thanks.

Zeeltronic is what I'm looking into at the moment have actually seen some good improvements on 125cc bikes over stock units but still unsure wether it's worth the money or not to have it fitted to a dtr 

Well funny we talk about CDi units this is what I wrote last night on another post

checked the coil connections they seem good, tryed to kick start it and after 20 kicks a almighty bang kind of short noise ? ,not from exhaust,somewhere at front, bloody baffled but a feeling that CDi unit may be at fault .

Have been around engineering long enougth  to tell the differance from a miss fire to a electrical short so its electrical for sure,to be quite honest getting fed up of constantly working on bike would just like to ride the dam thing.

Have you checked the ignition barrel as they have a tendency to vibrate loose 

Will check Chalkey, but sound seems to be coming from cdi area

There's a project thread by a guy called Calum, he used a zeeltronic CDI, might be worth a look at it!

do the cdi plugs and sockets look in good order?

Yes Airhead they look in good order.

well thought I would do a compression test and it came up at 60 psi ( think it should be about 120 psi cold ) so rings looked a little stuck in piston to me so sprayed WD in for a hour and did another compression test and it came up at 80 psi, 

So going to soak in a mixture of 2 stroke oil and WD overnight and see what it reads in the morning, will get back to you, so far 3 hrs of riding vs 40 hrs of maintenance great fun not .

So did another compression test and it came up to 90 psi not good 

Edited November 22, 20159 yr by Leftyno1