DT125R ARCHIVE

Monkey · DTR Member

dt125 running rough on half throttle

DTR NESTOR · DTR Senior Member

hi has it been previously running ok? and has it recently had anything done to it that may have effected how it runs?

Monkey · DTR Member

Hi, it's just had a rebuild with new con rod, bearings, piston, gaskets etc, and hasn't been running for about 3 years prior, I've taken the carb apart and cleaned it all out, everything is as it should be I think, I haven't had the power valve out though and there's no cable or servo on it, it's just standard I believe, it does have a big one rear silencer on it too, it wasn't running before it was taken apart but started first kick when put back together, cheers

JORDAN-43 · DTR Respected Member

try a new spark plug before anything

DTR NESTOR · DTR Senior Member

hhmmmm. i would check... your reeds and your airbox and also your spark plug.
Im guessing it had all new gaskets then?
and a new spark plug?
also has the air box been changed in anyway?

Monkey · DTR Member

Yeah all new gaskets, seals, plug, airbox is standard, i'll have another play with it when i got some time this week, just wondered if there is anything obvious i should be looking for, its a tad annoying as its a nice bike apart from this little problem, cheers

Monkey · DTR Member

Does having that big one rear pipe make a difference to the carb, would it need a bigger jet?

JORDAN-43 · DTR Respected Member

no

DTR NESTOR · DTR Senior Member

hi, you should check your oil pump setting to make sure your not gotting to little to much oil.
Too much will cause "bogging".
Does it smoke alot?

Monkey · DTR Member

No, doesn't smoke really badly, Just a small amount which I prefer with 2 stroke, had a chat with a mate today and he said to check the power valve to make sure it's not stuck closed, does this sound likely?

DTR NESTOR · DTR Senior Member

id defo check it, it you can see the position of it throught your exhaust port, just take the exhaust of and have a look down, it should be sitting flush to the rim so there is no restriciton.

NathanDavies · Guru

http://www.activeboard.com/forum.spark?aBID=66365&p=3&topicID=39715730

-- Edited by NathanDavies on Tuesday 7th of December 2010 01:14:06 AM

Monkey · DTR Member

Hi again guys, I've just come to try it now and it starts on choke but cuts out again quickly and won't run, when I take the plug out it is wet and has a weak spark, I've measured resistance across the coil as per Haynes manual, the primary coil is measuring fine but the secondary coil between the jut lead and the coil has no reading at all, does this indicate the coil is knackered? Just want to make sure before I go replacing parts that don't need to be, cheers