alright fellas got a wee bit of a problem with the dt125 .

had the bike out yesderday for first time in a few months ,was stored in my garage after a service new coolant oil ect..

was strated every week just to keep the old engine lubed up nice.

so too cut it short i took her out gave her a few laps round my way and then decided i would hit a trail not to far from me for a bit of crack!! (crack all right) as soon as i hit the dirt gave her the dig and held her on a nice weelie in second to 3rd. repeated the same and snap crack wheel lock up engine died silence!

so i was stuck on my own no signal on phone were i was brilliiant...

looked down the chain was of the rear cog and wedged between the bolts of the sproket.

chain still intact not snapped. so i manage to get it release it wasnt half stuck tho rolled it back onto the sprocket drove it straight home 2 mile slow as i new my chain must of been loose.and i could here it clinging and wacking on the swing arm-chain guard .

so straight into garage on the stand checked all over chain fine sprockets fine.

but looked closer and saw the dreaded sight of broken engine case no damage to the actual main cases just the wee cover on top behind the chain guard on the engine now i do its there it looks a right sight but as i say didnt crack engine thankfully. but just rount the front sprocket there is well was a kind of black block that slid into behind the fornt sprocket not to sure what this is but its in 2bits on my kitchen side.

so put the chain all back on checked all was right alligned chain ajusted right hit the road and noticed in 2nd gear it would judder from the back wheel and like a clicking noise, so straight home wheel of checked all bearings axel all fine. so what could this be...???? im thinking second gear fooked as i cant think of anythink else other that new chain sprokets but dont want to go get em and realise they wasnt needed.. so any input would be great hopefully someone no of or has experiance this before... and if so it is the gear. them bottom ends hard to do? thanks in advance people.. dluke

Buy a new chain and sprokets.

Yours are obviously nacked. By its design a chain cannot come off unless its hideously adjusted or nacked.

Buy a new chain and sprokets.

Yours are obviously nacked. By its design a chain cannot come off unless its hideously adjusted or nacked.

the chain was loose i think. would that be the reason its makeing a noise in second gear like kind of jumping?

the sprockets look fine no worn shark teeth and aalso looked all over chain seem fine.

anyone reccomend a good chain sprocket kit? was looking at the did chain the double o type for 40 kwid

I believe that DID are thought to be a good brand. That's what i put on my XT way back when and i have no complaints.

whats this black block in 2 bits then luke, post up a picture it may be relevant and dont ask me how to post pics!

l

whats this black block in 2 bits then luke, post up a picture it may be relevant and dont ask me how to post pics!

lol ill try get 1 up asap. its like a black piece of granite plastic hard to explain right behind- infront of the drive sprocket.

http://s1011.photobucket.com/user/dtluke/media/WP_20140121_006_zps6b9abab7.jpg.html

http://s1011.photobucket.com/user/dtluke/media/WP_20140121_002_zps4f3898ae.jpg.html

Edited January 21, 201411 yr by drewpy

I believe that DID are thought to be a good brand. That's what i put on my XT way back when and i have no complaints.

cheers might grab it mate looks good nice gold 1

STOP using the bike until you replace that spacer or you'll risk f*cking up the splines on you gearbox sprocket shaft (output shaft) due to the sprocket wobbling about!

see item 25

https://www.motorcyclespareparts.eu/special-pages/model.aspx?brand=4&type=13&year=352716&model=352761&part=352788

available from yamaha part# 90387205U0

https://www.fowlersparts.co.uk/search/part/90387205U0

Edited January 21, 201411 yr by drewpy

http://s1011.photobucket.com/user/dtluke/media/WP_20140121_006_zpsd450935d.jpg.html

Edited January 21, 201411 yr by drewpy

so would that be the problem? i did check well wiggle the sprocket seemed tight..ps hopefully u dont think i mean that plastic bit that had broken it isnt ill try see if i can see it on the parts diagram the pic above has an arrow the piece sits just infront of the sprocket faceing towards the bike.

it kind of looks like number 8 http://www.oemmotorparts.com/oem5.asp?M=Yamaha&T=DT%20X%20%20125&Y=2005&L=YA-DT-X-125&O=CRANKCASE%20COVER&F=YA-DT-X-125_AK&L2=YA-DT-X-125_AK

not to sure but that looks the same size as my broken bit but im sure mine is in 2 now so would of been bigger im confused. they call it a guide inlet any one any ideas what its use is?

Ahh yes forget what I said, you are right it's item 8 in your link

https://www.motorcyclespareparts.eu/genuine-spare-parts/yamaha3mb153770100.aspx?pagesize=20

Ahh yes forget what I said, you are right it's item 8 in your link

so what does that do then mate? doesnt look like much

so what does that do then mate? doesnt look like much

I dunno luke but if it didnt have a purpose it wouldnt be there, you're gonna need a new / used casing now though eh?

I dunno luke but if it didnt have a purpose it wouldnt be there, you're gonna need a new / used casing now though eh?

im not 2 sure weather i will as theres no cracks or bangs to the main cases just the top guard bit was going to just leave it as it will mean splitting the cases i think because the bit thats broke is not on the main case im think from memory.. so not much i can do except a new LH side crankcase. like i say i hope it will be ok as i cant see damage to the main engine case.

would love to know why that clicking noise is there its only in second gear .really cant see what the guide inlet could be doing it slots back in lovely its like groves it sits into.

best case is you damaged the chain and or sprockets

worst case is you damaged the gearbox

as it only happens in 2nd it doesnt look good does it!