DT125R ARCHIVE

DTR NESTOR · DTR Senior Member

engine rattle

craigbulmer · Guru

https://s881.photobucket.com/albums/ac14/craigbulmer/?action=view&current=IMG_0340.mp4

like that?

Spartan · DTR Senior Member

Hey nestor, has the barrel had a re-bore at all. The piston defo the correct diameter?

zo0op · DTR Senior Member

i had the same problem but my bike came like that, the piston was to small for the bore ... thats probily the cause of urz

dt_powerd_senda · DTR Senior Member

did u change small end bearing ? check for play in top end and check for play in crank mate

DTR NESTOR · DTR Senior Member

hi yep changed the small end and the oise in the vid clip isnt like it, it only rattles when like at the last 2-3000 rpm of the rev range.???

Dingle001 · DTR Senior Member

Take the power valve cover off and see if it rattles when the power valve has moved round into the high speed position? Otherwise, I agree it could be small end.

zo0op · DTR Senior Member

there was a topic on here b4 not sure who it was but it turned out to be somthing to do with the kick start assy .. its hard to tell with these bikes lol

DTR NESTOR · DTR Senior Member

hi ill check the power valve tomorrow then. thanks.

NorDt · Guru

about the video with the engine rattle,what was the reason for the rattle ?. My engine sounds alot like that, It has done 24854 miles or 40 000 km.

Im worried its the crank. What do you think ? I think the rattle started about 39 000 km. Then i seized the cyllinder and bought a brand new athena 170cc. still the same rattle.

NORFE · DTR Trusted Engine Builder

put a long screw driver on various points around the engine and put the other end to ur ear while running that will help u locate the sound, rattling or tapping noises normally come from a worn top end or piston hitting pv drum, worn crank is more like a loud knokking noise

check all chassis for loose fittings other kids was the brake lever ! if that what ui ment

other than that getr ur hands dirty and open it up check all specs to manual with some calipers

NorDt · Guru

The cyllinder and piston and top end is brand new, so its not that. Im guessing the powervalve comes fitting perfectly so it shouldnt be vibrating from that either.

But thanks for the tip about the screwdriver i can try that out.

I tried just feeling after any vibrations with my hand today, Couldnt find anything. When im on top of the engine it sounds as if its coming from the right side of the engine.

NORFE · DTR Trusted Engine Builder

could be the main bearings,take the mag cover off and try and wiggle the magnito in ur hand

whip the clutch cover off and feel for play,clutch centre hub makes some noise when thats shot

NorDt · Guru

Yeah i was thinking about that, Couldnt feel anything when i tried feeling for a glip on the rod. But i didnt know i could feel it on the clutch too.

Is it the main bearing i can feel if its going bad when i feel the cluch too ?

NorDt · Guru

Do you mean theres a bearing for the clutch that could be bad ?, Or something else with the clutch that could vibrate and make the sound ?.

NORFE · DTR Trusted Engine Builder

yeah thers main bearings on each side of the crank normally go with lack of lube in petrol

then therse aneedle foller bearing the clutch sits on grasp it in ur hand and try wabbling it does the noise go away when u pull the clutch in ??

NorDt · Guru

I dont actually know, i havent tried it, could try it out later ;)

NorDt · Guru

but i think its still there when i pull the clutch

NorDt · Guru

Could it come from the oil pump ? it hasnt been getting any oil in a long time. Since im mixing it in the fuel

NORFE · DTR Trusted Engine Builder

RE: engine rattle a wunta fortso

NorDt · Guru

RE: engine rattle

NorDt · Guru

Who is the owner of the bike thats on that video ?.

NORFE · DTR Trusted Engine Builder

could it be the oild pump.....i wouldnt of thought so! smile

NorDt · Guru

Dumb question ? xD, Sorry for that xD

satelliteone · DTR Senior Member

suspect bottom me thinks,

NorDt · Guru

Crank bearings ?

satelliteone · DTR Senior Member

yup, i bet the left hand bugger (magneto side), my dtr was worse than that, it sounded like a derv powered bike in the end.

They suffer that side too, but i would look at the crank carefully, inspect the shaft surface and the big end bearing.

Ive been down that road, had to replace the 6305r1 twice.

here is a vid i made when my left hand NEW bearing failed after 2Kmikes.

https://s31.photobucket.com/albums/c357/satelliteone/DTR125_1990/?action=view&current=NoSubject_22-01-2010.flv

Reason, the shaft was spinning on the inner race, and wore premature. These parts remember are interference fits.High strength locktight/threadlock on the shaft install, seems to cure it. Second bearing lasted till i sold the bike, 5K miles. still ging strong to date.

My bike sounded like that after 1K miles.

Sad to say, the engine has to come back out. but, take the barrel off, but dont split it from the head, saves u a had gasket. reverse on install.

NorDt · Guru

Okay thanks sattelion, So Your bike started sounding like this too ?.

satelliteone · DTR Senior Member

yup, it sounded like that, ignored it and it ended up getting worse, thinking its just a dtr sound..lol

Check everything tho, when its all to bits, even down to the teeth in the cogs, esp, the main drive cog/balancer shaft/clutch cog too. No nic`s in them and they run smooth around each other.

NorDt · Guru

Okay, Thanks dude :) i guess il just have to bite my theets together and get started. a mc shop close by could get me all the bearings i need for overhauling the crank for about 76gbp, And do the work about setting it up together with new bearings and balancing it for a ok price.

Thanks m8. 76gbp i think is pretty cheap, thinking it will be around 120 with the work of balancing it.

Ive done this on a 50cc once, a suzuki ts50x. just hoping its not too hard on my dt.