bike problem

[Manse]

Sons got a Yamaha DT125 thats doing our head in can any of you help out ?
when rev'ed water is spurting back up and out of the expansion tank under seat, so far we've had to do the following because it drained the rad and warped the head
skimmed head,new piston,re-bored , thermostat is working fine.
no one seems to be able to solve it even the shop that did the head.

 

[Erbs]

have you checked water pump impellor

maybe not working and overheating and going back into resovoir

maybe waterpump seal not sealing

had a dt and tzr's so know quite a bit about these 2 stokes

have been known to break on the impellor

 

[Oily]

Have you had the head or block pressure tested?Sounds like one or both are porous

 

[FUBAR69]

is it an older DT or is it a RE or what ?

 

[Erbs]

been speaking to my dad about this as he works for yamaha for 35 years

and what i have told him from your bikes symptons and that the the water pump bearing has worn

or seized due to seal not sealing

check waterpump and also clean rad and check fins are ok (not bent or crushed)

 

[Manse]

should of said its a 52 plate.
@Erbs cheers for the advice mate, some fins are a bit dented from stones being from up but in good shape otherwise.
He said waterpumps been tested and is ok so its off to a shop tomorrow to get looked over because im confined to the bedroom with swine flu.

 

[Erbs]

did you find out what prob was with your dt?

 

[Manse]

Its at a Yamaha specialist has i write Erbs.
tried again to have a look at the w/end but when i tried to bleed the rad the bloody banjo bolt to the warmer pipe on thermostat/carb snapped off lucky it was loose so it came out.
I had a Dt 10 yrs ago forgot how crap the bolts am on them, i was forever buying new ones for it.
will let you know though as soon as i find out what it is.

 

[Erbs]

nice one let me know as i'm very interested to find out what the problem is

 

[Erbs]

Hello Manse what was the prob with your bike in the end??

 

[Manse]

Bloody thing is still there mate, Was in there myself just yesterday having mine Mot'd (sailed through lol) and they are waiting for a new head gasket and they say its the only thing it could be.
All parts have been replaced that needed ie banjo bolt, its been pressure tested, water pumps ok, all pipes ok, even the mechanics is scatchin his bonce.
had'nt forgot ya mate just still in the shop and they can only give it 10 min here and there.
Son only had it 24hr got done for speeding and it packed up next day.

 

[Manse]

@Erbs
Finaly he got it yesterday.
Outcome was a full engine strip after they found who ever had put the bottom end back together DID'NT bother to use a new gasket they just used a mastic type and the old one together.
Pressure had caused bits off mastic to come off and block of nearly all outlets/ pipes and swim around in the oil but luckily the guy must of done it and sold it on straight away and it blew on my son before to much damage could be done.
Mechanic told us it was the worst case in seen in years but still only charged 2 hours labour instead of 5 roud:
£113 in the end for a gasket, new pipes, few bolts and a good hour of scrapping the shit out the bottom end.

 

[Erbs]

Bloody hell!!

you never know what your gonna get when buying vehicles, well i'm glad its sorted,

so basically a strip and rebuild and a bloody good clean!!!

thats a really good price you got for all that work............well done manse coz bike shops are on 45 an hour plus parts

bargain................now go out and and wring its neck