Hey everyone,

I am new to this forum, and I am new to owning a DT and so far I have had a nightmare with the bike.

I brought the bike of someone for a good price, and the bike look well presented, and well looked after. The bike is a 1995 DT125 and has done about 11,000 miles.

The problem I am currently suffering is that the bike accelerates OK, but when it hits the power valve the engine makes the sound of the sudden power increase but there is no noticeable power increase. I thought that it would be the clutch plates but there was no clutch slip 2 days ago before this problem?

A few days ago the bike overheated and one of the radiator pipes had been loose so it blew all of the coolant out of the engine, after that, came the powervalve problem.

Before the overheating problem, the bike is extremely sluggish before the powervalve, however if its given enough revs it does pick up,

I am at my knees with this bike, I have tried everything, but it seems the person who previously rebuilt this didn't do a very good job?

It had a new piston and rings on its last rebuild, or so im told. I brought the bike, wish I had looked it over more.

So my questions are,

Why would it make the sound of the powervalve opening without giving the power?

I took the powervalve casing off, and the middle of the valve bush just spins around, is it supposed to move when its at high revs to open and then return back to being closed? When I rev it, the thing just seems to move based on vibration? it can spin all the way round?

Why is the bike sluggish at low revs?

(We have checked the carb, seems to be very clean, although at the very top one of the screws had sheered off leaving half the screw in the top and a small gap, which we have plugged with rubber gasket sealant, would this impact also? Oh and the bike has a flat battery,

If anyone can advise that would be great, if someone could also give us an idea of how the powervalve should work/ be setup that would also be great,

Cheers

Daniel

sounds like your carb isnt set right, i have the same problem at the mo on my tzr185r, veing a rite bitch! i had a tzr125r with a 30mm carb, yeah it ran and accelerated but then i stuck a 28mm carb from my crosser which i knew was jetted to a tolerabl;e 125 engine requirements, its went like stink! dt 125 standard issue rejet should be about 50quid.

you said you lost a rad rose.... let me guess it was the one on top of the cyclinder (next to spark plug) if so this wasnt loose its the tell-tale sign of a warped head (easy fix) watch this rad pipe when your riding (obviously stop and check) it will be twice its usual thickness (b'coz your cylinder pressure is getting into your water system, hence blowing pipes off, if it was a diff pipe then let me know, ive been tinkering with these engines (dt-tzr only) foir a few yrs and swear by them! great indestructable little engi

is this the servo fed powervalve model? i know some have a electric resrictor to open the P/valve at 6k ish and then close it again about 9-10k, if so peg it in open position and see if you still have the same top end power issues, if so its carb or possibly the start of head warpage (dont leave unchecked for too long