DT125R ARCHIVE

NEV · Guru

WTF IS THIS RATTLE!!!!!

PatMan · Guru

HELLO LADS,

So after another engine rebuild, I started my bike up today to hear this annoying rattle/tapping, the cylinder has been rebored, new piston and rings, genuine gaskets, and the oil is flowing through nicely, I have posted a link below of the video so you can all hear whats going on, the bike runs fine, just I cant locate exactly where this rattle is coming from but I am sure SOMEONE will know for sure, as theres been other posts on this but no one seems to give a definate answer to what the rattling is all about. This never done it before the rebuild so not sure why its doing it now.

Cheers Lads

https://s782.photobucket.com/albums/yy106/PatmanUk/ENGINE%20RATTLE/?action=view&current=IMG_0642.mp4

Seiki · Admin

Sounds just like mine before the crank went snap. Not saying that's what it is just saying I know that sound.

You'll have to strip that man to investigate

PatMan · Guru

Hello Nev and Seiki mate........Right its been rebored to 58mm head gasket to suit has been done and so has the powervalve grinded down, and it does sound like that bloody kickstart thing.........Seiki mate i am soooooo hoping I havent got to do that, that will be a pain, I did check the crank before the rebuild theres play side to side but no play up and down, but if you know the sound then its what I am looking for mate, what do you suggest mate, new crank? etc?

NORFE · DTR Trusted Engine Builder

OUTCH!!!

sound nice somets nasty that one, start with the top end strip and inspect, sounds like sumets catching some where look for polished marks/contact marks, sound like the piston hitting the pv, idid my pv and built it then ran it sounded same so had to take some more off, try taking the pv drum out and put covers back on and run it

DT-R_bradders · Guru

sounds like mine but worse, try taking the expanny off n give the piston a poke to see if theres any movement, on mine there is, sounds bad to have movment like that but mine runs well and has good compression thats all i can think of that the sound is on mine, does it do it constantly or only at low rpm? another thing is that the rebore wasnt done to within tolerances did they have your new piston to match the bore to it??

PatMan · Guru

Thanks for the advice, Norfe and bradders mate, funny you should say that you dont really hear it when I rev it to 4k revs, only seems to be worse on idle, the bore was matched with the piston mate, this is why I dont think its actually the top end rebuild itself, cos has the exhaust off twice today and it still looks all good up the port, even took powervalve out aswell too have a look, everything looks normal, something is telling me for some reason its coming from inside the left hand crank case, but I am still a novice, need to pin point this quick cant keep taking it apart etc, its a nightmare

DT-R_bradders · Guru

one way to pin point a rattle or knock is get a longish screw driver push the handle end on to ur ear and push the other end on various different places on the engine you will hear it loudly but not always clear but worth a try m8 seen as the rattle is quite loud u might be able to pin point roughly wer its comin from

NorDt · Guru

Take of the side plate that covers the stator. Then take the flywheel and just pull a bit upwards and downwards to check if theres any free play on it. If its not then you know its not your crank ;).

PatMan · Guru

Thanks mate won't beable to get onto it till Friday now will keep everyone posted for future reference

NorDt · Guru

k ;) I had that rattle too. Im currently doing a engine rebuild. New crank and bearings. When i felt my flywheel i could feel a tiny glip. not much. i seized my engine alot of times, and my all new 170cc had the same wear marks on the same spots my other piston seized. So im pretty shure my bad crank and bearings caused it.

satelliteone · DTR Senior Member

turn the pv to fully open pos. , dis connect the 5 pin plug to the pv. start the bike. just to eliminate it.

quite a bad sound that.. i be curious to know what that is.

coastie123 · DTR Senior Member

Look at this on eBay:

SERVICE BARREL NEW REBORE PISTON KIT FULL GASKET SET YAMAHA DT 125 R DTR

http://bit.ly/xwg3sm

His name is Andy, great guy and there's a few on here that's used him for a rebore.. He sorting out my parts for me..

NORFE · DTR Trusted Engine Builder

coastie123 wrote:
Look at this on eBay:

SERVICE BARREL NEW REBORE PISTON KIT FULL GASKET SET YAMAHA DT 125 R DTR

http://bit.ly/xwg3sm

His name is Andy, great guy and there's a few on here that's used him for a rebore.. He sorting out my parts for me..

yes i can vouch for andy hes sound quick and cheap !

PatMan · Guru

Have done the powervalve thing mate and it still does it am thinking what norDT and seiki say something to do with under the piston, but it makes me wonder before the piston seized due to a oil block, it was spot on, rebuilt top end and now this hmmmmmmm, have done top ends before so everything went back right

satelliteone · DTR Senior Member

That sound , really quite a metal knock, relation to the piston going up and down. To know where that knock is , piston up or down, i wonder if you mark the fly wheel with tipex,(cover off) note the position when running, to where the tipex mark is , Eg TDC, might give you a better idea. get the engine to run realy slow, to the point of stall. where it knocks, to where that tipex mark is.

PatMan · Guru

That's a good idea thankyou mate, have been thinking though is it worth sticking another engine in it? If anyone has a good one? Reason I say this is just don't have the knowledge to pull the whole engine apart to investigate, never done a bottom end rebuild before or even dropped the engine as a matter of fact, a seems hard work

........ok 1 more thing I forgot to say lads, when the piston seized the bloke from the local bike customs shop told me, to pour brake cleaner down the crank, to the top, give the bike a shake and tip it all out so no metal pieces from the piston are left in down there, I did this twice to make sure and blew an air compressor thing down there to make sure it was dry, before I started to rebuild top end,everything when back as it should etc just like my last rebuild, powervalve grinded down so it's not hitting piston and top gasket grinded to suit bore size, I didn't change the small end bearing as that was still like new only 700 miles new, has to be under the piston or as you say fly wheel area!!!!!

satelliteone · DTR Senior Member

Bummer aint it, might have got as damaged bottom end bearing. Thats 100 quid for PJME to renew. Somthin in either loose, or hitting somthin.

Was the sieze a solid one, like instant?, or a more of smack , push type of seize? strain on the conrod, will flat spot the needle bearings in a conrod bottom end. Any play in the conrod, (not all postions) can lead to a knock.

To take apart the bottem end, renew all the bearings and seals, plus the crank, aint cheap. Unless u know bradders..lol

I did my TZR last year, its now spot on. But i got empty pockets now..lol

PatMan · Guru

Jesus mate how much we talking here, I wonder if bradders has any parts laying about I thought the bearings and seals were quite cheap or is it the crank which costs alot, could you please tell me the exact stuff I need to get please mate

and thankyou do much for the info

NORFE · DTR Trusted Engine Builder

main bearings & seals,

little end,con rod kit & fitting

gasket set

check all top end to manual spec with some calipers that bout it not much to these engines once there opened up, good thing about 2 strokes theres not to much to go wrong due to the amount of parts unlike a 4 stroke

NORFE · DTR Trusted Engine Builder

and somet mekin that much noise will be easy to find aswell

coastie123 · DTR Senior Member

For my rebuild - all parts for top and bottom are £193 including the barrel being sent for a rebore and being posted back with all the parts..

A new crank if needed will cost you about £130

PatMan · Guru

Thankyou Norfe mate will get on it at the weekend am hoping it is this then don't wanna sort bottom end out then the rattle is still there :-s

PatMan · Guru

Ps do you have a website where I can get that stuff from, refuse to go to local Yamaha dealer after they fooooked my bike last time!!!!!

satelliteone · DTR Senior Member

i use these guys

rebore

http://www.pjme.co.uk/acatalog/Cylinder_Re-Boring.html

crank

http://www.pjme.co.uk/acatalog/Crank_Shaft_Rebuilding.html

complete engine rebuilds

http://www.pjme.co.uk/acatalog/Engine_Rebuilding.html

best to ring them for a quote tho.

or justbuy another known good engine,

PatMan · Guru

Once I located the problem lads I will take it from there but thankyou so much for everyone's help makes me alot happier

poxy bike grrrrrrrrrr

coastie123 · DTR Senior Member

One thing I'll say about pj engineering... They know there stuff but boy do you pay for it...

They charge £207.99 for a rebore, conrod and piston kit and for the same price you can get the complete rebuild parts from that Andy!!!!

DT-R_bradders · Guru

wat was it patman??

NORFE · DTR Trusted Engine Builder

any joy on the problem? where do u live?if ur any where up this way nottinghamshire fetch me ur engine and parts and £40 and ill strip and build it for while you wait & watch teach u the basics if u want mate

takes about an hour and half to do complete engine with a good check over and fit new bits

smile

PatMan · Guru

Won't be able to look at it till weekend lads and am in Sussex Norfe dam it, but thankyou so much for wanting to help......was just saying bradders mate about my bike rattling like hell at the moment and your the man to ask on parts etc hehe, I wil get the manual out and do it step by step, but can I ask when splitting the engine in 2 after taking the top end off and side casings, do I have to take all the clutch plates/basket off aswell and all the stuff inside the left hand side casing? Or can all this stay on while I pull the engine in 2?