DT125R ARCHIVE

Dt Danny · Guru

RE: Rip my dt 125 :(

Dt Danny · Guru

but i need to get it out of the bike first which is annoying me

GADGET · Guru

Just go for it ,start by takin the oil n water out ,then just undo all the pipes etc ,and then unbolt it and its out once you've done it you will wonder what all the fuss was about ,I can walk you thru it if you want ?

Dt Danny · Guru

yeh ive got the head off etc just taking the swing arm off thats all lol

NORFE · DTR Trusted Engine Builder

Calum122 wrote:
Yeah. But the swing arm is a piece of piss.

Two nuts and that bad boi is off.

if its had a well greased life....if its dry its drift & sledge hammer time

scrimsmustang · DTR Mechanic

Ive never heard as much bollox about an engine in the 30 years ive messed about with bikes not just DT125R,s. That bottom end will be fine if its flushed out properly and the mains are not rumbling with a free turning crank with no up down travel on the rod.

But thats just my opinion with over 20 years as a Yamaha dealer mechanic.

NORFE · DTR Trusted Engine Builder

yeah but how can u see if youv got it all out, there could be lumps of alloy stuck to the cages of the bearings, or any any other nook and cranny, every time iv seen some one put a new top end on a blown up engine its failed, weather it be piston bits,ring bits come up out of a fully flushed crank case.....and wreck the new bore/piston in no time

starts rattling & loosing compression after 1 run

i wunt spend money rebuilding a top end for it to go pop again 50 /50 chance id rather do a job right 1st time instead of spending twice

Calum122 · Guru

NORFE wrote:
yeah but how can u see if youv got it all out, there could be lumps of alloy stuck to the cages of the bearings, or any any other nook and cranny, every time iv seen some one put a new top end on a blown up engine its failed, weather it be piston bits,ring bits come up out of a fully flushed crank case.....and wreck the new bore/piston in no time
starts rattling & loosing compression after 1 run
i wunt spend money rebuilding a top end for it to go pop again 50 /50 chance id rather do a job right 1st time instead of spending twice

+1

there is no point in taking any chances. Especially when you're seventeen with no money to make these sorts of mistakes. I understand the temptation in taking a shortcut but in the long run I'd rather spend that little bit more and wait a little while longer. As said if this was me and I was told I need to sort the top end out I would have done it there and then.

even now my only form of transport has been off the road for 6 months. And I'be got loads of mods on it that I want to try out. But I'd rather sort out the top end first as know it is due maintenance.

Dt Danny · Guru

yeh same here but when my grandad asked about the cost he was in shock lol but this swing arm bolt is a whore

NEV · Guru

Remember that when trying to knock the swingarm bolt out, to put the nut on a couple of threads, then try and knock it/drift it out, because if you don't, you'll more than likely bugger up the thread.

NORFE · DTR Trusted Engine Builder

Danny0112 wrote:
yeh same here but when my grandad asked about the cost he was in shock lol but this swing arm bolt is a whore

plenty have 1 spare on here mate for a few quid..... just remember grease when re-fitting

Calum122 · Guru

Lol. What was he expecting for a full engine rebuild. Also you ought invest in some tools mate.

One of my favourite tools in the garage is a rubber mallet.

Dt Danny · Guru

yeh i was starting my tool collection but then this went pop lol and i found most nuts on the dt to be 10 mm

scrimsmustang · DTR Mechanic

Controversial comment from, wasnt really meant to have been. Like I said its just an opinion and I totally respect everyone else's, Ive seen DTR,s do 15k on a standard engine commuter bikes with top boxes on the racks. Then again ive seen them totally f****d after 3k with abused new DTX,s depends on who,s owned them and how they get ridden and treated. It could need the full monty but there is a good chance it could be fine as well if its well flushed out a few times and blew out a few times with an air line and if all looks and sounds well with the mains and the crank it should be fine.

I was just trying to save the fella a few quid if the bottom end is ok.

GADGET · Guru

Ohhhh the controversy,nah only kidding,we is all famo here wink

GADGET · Guru

I did re-use a shagged bottom end once on a ts50x ,all I did was flush it out,it lasted about a year but got worse and worse till it died and cost me a brand new 70cc bigbore kit coz it destroyed everything in the end ,if it was a crosser no probs ,if it a road bike I Wunt chance it .....when the ts70x finally gave up and seized I was doing 60 on the duel carriage way a skip lorry behind me,it locked up ,no brake lights coz it was engine stopping the bike and clutch wouldn't disengage coz everything in the lump got bent,lucky to be alive(was only 16) ashamed ashamed ashamed

stillbroke · Guru

Calum122 wrote:
NORFE wrote:
yeah but how can u see if youv got it all out, there could be lumps of alloy stuck to the cages of the bearings, or any any other nook and cranny, every time iv seen some one put a new top end on a blown up engine its failed, weather it be piston bits,ring bits come up out of a fully flushed crank case.....and wreck the new bore/piston in no time
starts rattling & loosing compression after 1 run
i wunt spend money rebuilding a top end for it to go pop again 50 /50 chance id rather do a job right 1st time instead of spending twice

i took the shortcuts read my threads......

+1

there is no point in taking any chances. Especially when you're seventeen with no money to make these sorts of mistakes. I understand the temptation in taking a shortcut but in the long run I'd rather spend that little bit more and wait a little while longer. As said if this was me and I was told I need to sort the top end out I would have done it there and then.

even now my only form of transport has been off the road for 6 months. And I'be got loads of mods on it that I want to try out. But I'd rather sort out the top end first as know it is due maintenance.

scrimsmustang · DTR Mechanic

F**k me its like talking to a brick wall, anyway anybody know how to machine the squish band on a YZ490 to stop it detonating ?

Probably a bottom end rebuild lol....................

I put a re lined cylinder and piston kit on my mates 07 RE with a Lanza motor in it over a year ago with a flushed bottom end and its still running fine now after it shattered a piston and cracked the liner.

-- Edited by scrimsmustang on Saturday 2nd of March 2013 10:33:51 PM

scrimsmustang · DTR Mechanic

Cause I get it Callum.

Thats why I have said someone who knows what to look listen and feel for needs to go and give the poor f****r a hand. If I was close I would go myself.

All im saying is there is a good chance its fine flushed and blew out thoroughly simple as... just cause its suffered a tolerance failure don't mean the thing is goosed all together. Im not trying to prove a point mate its a fact that there is every chance it could be fine.

Anyway nuf said if he has the funds I do agree now is a good time to send it to Norfe or whoever he wants to do the lot mains new rod kit and everything that goes with it while its half in bits its not a hard job even Norfe will tell you that, an hour od start to finish.

-- Edited by scrimsmustang on Saturday 2nd of March 2013 10:57:15 PM

Dt Danny · Guru

The engine is finaly out

Calum122 · Guru

Easy or easy?

Dt Danny · Guru

im never taking it out again lol

scrimsmustang · DTR Mechanic

At the end of the day I have flushed and blew out more DT bottom ends than I care to remember over the years, and none of them have came back shortly after needing new mains because they were all fine.

1

You know you have all the **** out because you cant see any of it anymore...........

2

You know its alright because all the bearings sound fine and everything is turning over freely looking feeling and sounding ok.............

3

Like the old saying goes, if it aint broke dont fix it............

Anyway he can do whatever he likes with it at the end of the day, after-all its his bike and to be honest it sounds like they have had enough trouble just getting the engine out never mind knowing if the bottom end is ok or it isnt............... Someone who knows what it should be like needs to take a look at it for him.

scrimsmustang · DTR Mechanic

1

That DT went bang because of a tolerance failure due to wear nothing more and nothing less "piston slap at the bottom of the bore".

2

That DT did not go bang because of a lack of 2stroke oil or coolant so it never suffered a melt down usually melting the piston crown and rings into each other..

3

That DT did not go bang due to a jetting/or mixture issue so it never suffered a melt down due to poor mixture usually causing a hole melted through the piston crown.

Hence, there is not much chance any bits of red hot piston have stuck to anything, the worst cause of damage in this type of failure is bits of piston jamming the crank to the cases and locking the motor abit like a melt down seizure but in a different way. If it were a melt down seizure it would have more chance of not being ok.

Dt Danny · Guru

i cannot wait till i get my bike all back together and on the road again

stillbroke · Guru

+1 scrim

Calum122 · Guru

He ran the bike with fragments of piston in the bottom end. It's damaged.

scrimsmustang · DTR Mechanic

Calum122 wrote:
He ran the bike with fragments of piston in the bottom end. It's damaged.

Not necaserily, yeah the piston and bore are definately damaged I will give u that.......:)

Dt Danny · Guru

scrimsmustang wrote:
Calum122 wrote:
He ran the bike with fragments of piston in the bottom end. It's damaged.
Not necaserily, yeah the piston and bore are definately damaged I will give u that.......:)

Lol the piston is .... the bore i dont think is tbh from what i can see but then again i know nothing but at least i have chance to clean the bike propper and grease all the bolts up and take care of some rust :) you always have to look on the bright side of things :D

scrimsmustang · DTR Mechanic

Yes the bore is shagged thats why the piston broke fella, it definitely needs a re bore.