DT125R ARCHIVE

ezegreenfingers · Guru

RE: engine is broken again

NORFE · DTR Trusted Engine Builder

has it got 4 siezures on the piston a 4 corner siezure will be lack of lube when its expanded to quick normally but can be to lean leaky seal or similar

ull have to strip the engine to clean it out proply bits get stuck all over the bearings mate then u spend £80 on a new top end onbly for particles of mushed up alloy to recirculater

if id had that happen id be checking the big end & replacing the 2 main bearing and the little end,or ull just be wastin money on a top end rebuild

but thats up to you mate

biggrin http://www.off-road.com/dirtbike/tech/dirt-bike-tech-twostroke-seizure-52428.html

tripr · Guru

I did mine with fuel once but with the engine still attached to the bike wasnt easy so the next time i did it .

i found flushing the bottom end is a hell of a lot easier if you remove the whole engine jus keep pouring in dabs of fuel swilling it about an tipping it out in to a small container till the flush is completly clear of particles

-- Edited by tripr on Wednesday 18th of July 2012 07:36:51 AM

-- Edited by tripr on Wednesday 18th of July 2012 07:38:02 AM

NORFE · DTR Trusted Engine Builder

you can never be sure that the bits are gone, theres all sorts of spaces the bits can stick to or hide behind, the oil journels 2 holes down each side are tight spaces to get in, and theres all the lips and balls of the bottom 2 main bearings for stuf to get trapped on, when the engine siezes it produces a like rubbing compound of alloy/oil mix like a gray sludge that will wreck bearings and other parts

if id ov had a siezure id be stripping the bottom end and inspecting every bit, or it only takes a small ammopunt of bits to completely wreck a new top end, so for the extra 2 h ours it would take to be sure the bottom end is ok i wunt just chuck a new top end on it and wast the money

u think at 12000 rpm the piston goes up and down the bore at 166 x per second

if it gets a small ammount of ally piston rubbing up and down on the piston or on a bearing its gonna make a mess then may be lock up the engine, snap the rod/piston break thru the crank cases then ur in a world of **** and expence,,,if ur gonna do it do it right and throughly so u no alls good before firing her up thats my way of thinking, on these small engines its a half day job to completely strip and repair the complet motor

then u no ur gonna have another 20.000 miles of decent running if well maintaned biggrin