DT125R ARCHIVE

CarlosRexx · Guru

Barron89 and his 30MPH top speed DT.

Ralzy · Guru

so no real acceleration i take it if so possibly choked air filter or exhaust system remove carbon build up from zaust & baffle possibly ignition timing not correctly set possible carburation fault have you checked theres is no mechanical resistance eg brakes not binding

-- Edited by Ralzy on Friday 6th of July 2012 01:41:25 AM

the only way is YAMAHA DTR · Guru

check the reeds arnt broken

CarlosRexx · Guru

And this is it under load, this is it's top speed..

Reef · Guru

I can see why your jealous of mine, LOL, had to be said, but hang in there, im sure your resolve the problem soon bud

CarlosRexx · Guru

For the record, this isn't mine :P This is Barron89s bike..

Mines rapid ;)

Reef · Guru

Yeah realized that straight after posting that lol... = FAIL ;)

Barron89 · DTR Respected Member

Yes yes very embarrssing! Any ideas in what the prob may be would be greatly appreciated. That was with the powerv pegged open and with a full dep exhaust! I have never checked the reeds, and i dont think mine has a reed switch.

Reef · Guru

No idea buddy, im a noob with the mechanical side of things, probs best to start another post in the "i dont know whats wrong section", should get some of the others to leave some advice :)

Barron89 · DTR Respected Member

cheers i will attempt that tomorrow, im a bit of a computer noob lol

MDK · DTR Legend

bloody hell that is slow dude what year is it ? have you even checked if it has the reed switch ?

have you ever had the carb off ? has some one put restrictions in other places.....sounds silly but some get them for the wife and place restrictions in other places ?

if was me and you mate has a dtr thats fast beside it I would try some of his running gear - cdi ect

something seems to be limiting the rev.s ..are you sure you have pinned the valve open ..sounds sily again but know of some who actualy slowed there bike down by doing it wrong .

hope we can help you sort this , so the peds no longer over take you lol

CarlosRexx · Guru

Haha, it's sad that this poor DT seems to be ill. I had a look at it, switched the pully from mine to it, as his is snapped where the pin goes to pin it open. Set the valve to the open position and it's still the same, the servo works fine. I was thinking electrical restriction

the only way is YAMAHA DTR · Guru

running on cooking oil lol. sounds like it hah

would be worth stripping to get her purring smile

start on simples first

NEV · Guru

I'm with the thinking it could be the reeds that is the problem here too, if it is bang some HY-TECK race ones in, just as good as Boyesons and much cheaper.

How did it get to be like this btw, was it ok, then just went? or gradually over time?, try changing spark plug for a new one too, as that can make a big difference, clean air filter also.

-- Edited by NEV on Friday 6th of July 2012 07:20:16 AM

MDK · DTR Legend

its a fact some dtr even if totaly good engines are slow had a mate with a 2000 and was more like a ped .. we never realy worked on it to see why and he sold it on as it was ...

could the cable to slider be restriced in some way ....

has some one put carb restrictors in place smaller holes ...

like said above it needs a day or to on a bench all plastics tank ect off and work at each point till ya nail it

Barron89 · DTR Respected Member

Ha yea thanks for your support it is heartbreaking!
First of all it does hit 45, after a hour lol and god help me if there's a incline!
Clock only has a thin green and black cable going to it do don't think these dials ever had a reed switch.
Full Dep new front pipe so no restrictions there
Operational power v
Just past it's mot new bearings pads etc

I havnt delved Ito the unknown parts like reeds or playing with carb and timings.

Barron89 · DTR Respected Member

The engine is roughly 2000 with a 3bn head but the bike is a 1990.

NEV · Guru

NEV wrote:
How did it get to be like this btw, was it ok, then just went? or gradually over time?,

Barron89 · DTR Respected Member

When I got the bike it was slower and in worse condition! Closed pv and blowing standard front pipe.
Yea think I will buy some reeds. Not sure what year to go for with a mixed up bike like mine

NEV · Guru

if its a 2000 engine get them for that, dont think they differ mind. get a new iridium plug in it too, a tad bit dearer but a better plug in my opinion.

the only way is YAMAHA DTR · Guru

just take off all the intake system, check it, clean carb out, see if the slide opens fully with the cable.

check the cdi hasn't been swaped or broken wires

ignition timing isnt adjustable, well atleast not on my 2003

MDK · DTR Legend

I would be tempted to try a older cdi from a 89 to 98

have you tried it witht the air filter out or snorkle removed ?

maybe give us some close up pics of the engine ect

or better a video you can give us a tour of the bike engine- carb -filter box - cdi - ect if possible also the inseide or ports of exhaust

on some carbs there is a screw adjuster on the top where the cable go,s throu how much is that wound out or sett to .

if some one has use a incorrect cable maybe it is not opening the carb/slider fully so your never gona get full revs /power

http://www.dtr125.net/tuningf.htm http://www.dtr125.net/tuningf.htm

CarlosRexx · Guru

If you need any more help Dom I'll happily help mate. As I'm close to you and have some knowledge

Ralzy · Guru

In general in the manual the timing can`t be adjusted but if there is a fault with cdi unit this would cause a fault to the timing i.e would cause the ignition timing to not be correctly set this what i mean in my 1st comment mate

-- Edited by Ralzy on Friday 6th of July 2012 11:24:21 PM

NorDt · Guru

Im thinking maybe its the ignition timing. Its mechanically adjusted like a TS 50 X right ?. Im thinking if this is set up really bad it might make the engine ignite at the wrong time so it cant reach any higher rpms..

Just a tought. I dont know much about ignition timing.

the only way is YAMAHA DTR · Guru

my bike you cant adjust the timing, the manual says you can't

if the timing was way out , the conrod would be bent etc

you need to get the carb and reed off to inspect!

NorDt · Guru

Okay ;)

Calum122 · Guru

Needs to check to see if the Power valve is actually doing what it is designed to do. Mine will have no power at all if the P.V. is shut. It'll accellerate like mad then get to like 40 mph and bottom out.

FunkeyMunkeyDavid · Guru

i've had a dt do this... turned out to be detonation which put a dent in the piston,dropped the compession to near nothing... and ditch the 3bn head,they awful doh

Energized · DTR Legend

3mb head is so much better looked at my old head in garage early today and compared to a 3mb there is defo a better squish band and better low-mid power, still pulls like a train up top.