DT125R ARCHIVE

Slinky · DTR Senior Member

Engine Dismantling

the only way is YAMAHA DTR · Guru

use impact drive on the buggers, i had a pain getting mine out

DT-R_bradders · Guru

on some of the casing bolts u can just about get some mole grips on the heads and turn it slightly to crack em off, or u can tap (dont be shy hit it!!) the screw driver with a hammer and turn at the same time, if all that fails buy a impact driver like "the only way" said : )

NORFE · DTR Trusted Engine Builder

put the whole bottom end in the oven for half hour get it hot done that b4, hammer /screw driver and or impact driver

then replace all the bolts with stainless cap heads never have the same problem again

smile

mr karnage · Guru

my bikes a 1990 and the bolts on mine looked like they never came out

i rounded nearly all of them using an impact driver so i used a screw driver and hammer, along with some penetrating oil. it works wonders

i got them all out using that method

you should have seen state on them when i did get them out, looked like i sawed into the head lol

-- Edited by mr karnage on Thursday 26th of January 2012 06:28:30 PM

NEV · Guru

Aye, I get what your saying, but instead of a 6mm thread picture it all in your head and blow it right up to say a 6" thread, so you understand the bigger picture, you've undone the screw say a turn an a half, but cant get any more purchase on the cross head due to it being buggered, so like you say you bang a flathead screwdriver a few times so as to turn it into a flathead, but remember the screw is mild steel and the thread in the casing is ally, imagine the threads being pushed in by the screw and buggering up the thread on the casing, whereas tapping it round only puts pressure on one side of the thread,
Ah yes I hear ya say thats what an inmpact driver does, and you'd be right, but remember the head of the screw is sat right up against the casing, which is when you usually need to use it, just to crack it open, not stuck out a mill or two, which would be around 1 pitch.
Bit long winded I know, but can save you a few bob in the long run by having to have it helicoiled.

Plus stud extracting kits are a well worthwile investment for buggered screws.

-- Edited by NEV on Thursday 26th of January 2012 07:29:39 PM

fused420 · DTR Senior Member

I used these just the other day,

http://www.ebay.co.uk/itm/150484780128?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

http://www.ebay.co.uk/itm/150484780128?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Worked a treat :)

-- Edited by fused420 on Thursday 26th of January 2012 08:00:02 PM

dtx zac · DTR Senior Member

Bet your other half loves you norfe ahaha

the only way is YAMAHA DTR · Guru

bet the idiot at yamaha that decided to use crosshead bolts got the sack lol

fused420 · DTR Senior Member

the only way is YAMAHA DTR wrote:
bet the idiot at yamaha that decided to use crosshead bolts got the sack lol

I hope so!

Slinky · DTR Senior Member

mr karnage wrote:
my bikes a 1990 and the bolts on mine looked like they never came out

i rounded nearly all of them using an impact driver so i used a screw driver and hammer, along with some penetrating oil. it works wonders

i got them all out using that method
you should have seen state on them when i did get them out, looked like i sawed into the head lol

-- Edited by mr karnage on Thursday 26th of January 2012 06:28:30 PM

So basically just chisel the heads off the buggers?

NEV · Guru

Put a little nick with the screwdriver about "2 o'clock" then tap it around anti-clockwise, would be my guess.

fused420 · DTR Senior Member

I used a chisel to turn the bad ones into flat heads

Slinky · DTR Senior Member

II'll give it a go and see how I get on. Whatever happens some decent replacement bolts will be ordered...

fused420 · DTR Senior Member

You will need m6x50 and m6x60, i brought about 10 of each for a couple of quid from ebay.

NEV · Guru

Fused you sure mate? m6? 6mm thread is m10

Slinky · DTR Senior Member

Are the pro bolt ones worth the extra money?

fused420 · DTR Senior Member

I might be wrong but i think the pro bolts are made of alloy, and no better then the original screws..

mr karnage · Guru

i dont mean hammer the screw dead on straight and definatley not hammer the head off!!

use a flat head screwdriver and put it at an angle so it sits in one of the grooves then tap it with a hammer, its kinda like doing the job of an impact driver.

your just screwing it by tapping the hammer, youll get the hang of it

mr karnage · Guru

fused420 wrote:
I might be wrong but i think the pro bolts are made of alloy, and no better then the original screws..

they do them in aluminium, stainless and titanium

they are a bit over priced, i get stainless allen bolts off ebay

NEV · Guru

Ah right with ya now,
I read it as this
" I used a chisel to turn the bad ones into flat heads"

mr karnage · Guru

that would have done nothing lol, even an impact driver didnt work on mine

NORFE · DTR Trusted Engine Builder

dtx zac wrote:
Bet your other half loves you norfe ahaha

ha ha ...i dont give a fook i need to do it i doit ha ha. bits in dish washer is her most dislike ha ha

NORFE · DTR Trusted Engine Builder

yeah all m6 bolts on the engine, m10 bolts are normally 17mm or 15.. hex head ring spanner size

NORFE · DTR Trusted Engine Builder

dont for get people thers loads of different phillips bits all different angles and sizes, if you dont get the right one to match the screw head it wont fit proply flat6 headed/pointed fat /thin all sorts and chew it up plus the screws used arnt hardened so are pretty soft

if you look in the manuals it will tell you all about the angles of the bits in the tools section

i got a proper one to match the screws on a few engines iv had and one tap with the driver and straight out

mr karnage · Guru

when i got my little halfords socket set, it had all the philips and cross head bits in

i havent rounded off a screw since

NORFE · DTR Trusted Engine Builder

yeah iv about 12 i think all different, me either

alot of people think there 1 phillips and one flat lol

its all in the manual before any works started well it normally is

but alot of people just whip the engines out of stuff with out lookin, no matter how good u think u are or how many motors you have built every engines different, so reading that specific book is a wealth of nolidge, and shunt be over looked smile

mr karnage · Guru

yh man, its the reason i joined forum

theres alot you can learn on here

Gambodia · DTR Senior Member

Iv lost my manual lol , what size are the engine bolts ie:PZ1 PZ2 PH1 etc?

NORFE · DTR Trusted Engine Builder

all the bolts on the engine are M6

apart from the oil drain bolt thats M8

and m8 nuts on the head and barrel