New purchase 1990 dt125r

[declan]

@ukchad might aswell throw a new piston in there while our at it

[oldman]

Head refurb really straightforward, just get a decent gasket set, take your time and follow the manual. Did mine while I had the engine out, takes no time really. Nice bike, gotta save these old ones

[terry.tz]

@ukchad head is easy best done with a torque wrench thou if you're willing to buy one

[ukchad]

Another tool to purchase, but I do love having them.

[terry.tz]

@ukchad said in New purchase 1990 dt125r:

I actually put the power valve back to original position as the exhaust got very hot very quickly (smoking from end after I stopped after a 5 min blast)

haha I would say leave it open its boring closed I could fall asleep riding if it was not wide open but I will say I have seen threads where there is a bit of controversy so think it's best you know how your bike runs first so you will tell if it rich or lean through the rev range

[declan]

@ukchad

Another 1990 welcome! Ignore the sticker bomb and the rear wheel got a puncture in my wheel and chipped paint underneath the sticker bomb lol

[terry.tz]

@declan coming on that is Declan

[oldman]

Here's one I prepared earlier !
0_1502570553952_20170715_131805.jpg

[ukchad]

Is it normal for the exhaust to heat up so much then, when the power valve is fully open?

Also died a bit when I kicked up into 6th, ran out of power (maybe wasn't high enough revs)

[ukchad]

@oldman soooo clean

[declan]

@ukchad coming from 4 stroke this was crazy for me I have full functioning pv) my muffler gets too hot to touch

[declan]

@terry-tz hey thank you buddy nice hearing that much appreciated but a lot to go yet

[terry.tz]

@declan good to know there's more to come

[Calum]

Hello and welcome'

Get the servo retro fitted and have a working powervalve. Best of both worlds.

Exhaust gets hotter because you spend longer times at higher rpms. Refer back to my previous statement. Get the servo fitted. Less stress on the engine.

I would start simple first, check the thermostat, they are probe to failing after zo many years.

Head gasket is not the same as a four stroke. No valves no nothing to go wrong.

Buy only genuine or athena gasket, skim the head like described in my tutorial, then boom, good to go.

Nice bike.

[Minia]

Welcome, looking good

[declan]

@calum what's skimming the head do I know squish and compression etc but does just that on its own yield noticeable results?

[NINJA]

@ukchad Welcome aboard, looks like you have a decent starting point there.

[ukchad]

@calum so I think I understand.

At the moment the power valve either works at low down or higher revs because it is fixed in position?
I choose that position by turning 180 degrees either way?
By fitting a servo, the power valve is rotated to give me full power depending on revs.
Is this correct?

My power valve doesn't look like most i see in pictures - no cables or slots for cables in the casing. Just a central bolt, flanked by 2 small outer bolts

Can a servo still be retro fitted to this?

[Nottsbiker]

Yes you are missing the cables, servo, cable housing, cover and pulley.

You can get these from any DTR or TDR and they will fit your bike. Not sure on servo motor but i think any DT one can be adapted to fit

[ukchad]

Thanks @Nottsbiker

If any one knows, finds or has one that fits please bear me in mind.

I can then start a build thread and you can all watch me mess it up!