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DT50 MX engine problems


Sami
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hey

looking for some idea as to what he cause of the engine problem on my bike is .

heres her story

i bought her off ebay , stripeed her down like u do , to refurbish her , as i had her sitting about for a few month before i was 16 . :) ran perfectly afterwards up and down the tracks , when i got her on the road it was winter but i still had 3 onths of bliss . then trouble started.

i first had to replace the fuel filter as fuel was leaking from the old one

she had another tap put on the petrol tank too , we cleaned the carb after the first time she droppped revs and this seemed to solve the problem

however riding her home a month ago in the puring rain she cut out and wouldnt start again , thinking she'd seized up i push her home and sat her in the garage to be fixed , but she started on second kick and ticked over perfectly the next day.

last weekend she died and siezed up in the hot weather , we bought a bg bore kit , fitted it and it seemed all ok when i was riding her round the block.

but now the problems back .. she slows down theen stops likes the engine seizes , but then 5 minutes after she kickstarts and goes for another 10 minutes then cuts out and does the same .

anyone think they can help ?? please ?

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hey

looking for some idea as to what he cause of the engine problem on my bike is .

heres her story

i bought her off ebay , stripeed her down like u do , to refurbish her , as i had her sitting about for a few month before i was 16 . :) ran perfectly afterwards up and down the tracks , when i got her on the road it was winter but i still had 3 onths of bliss . then trouble started.

i first had to replace the fuel filter as fuel was leaking from the old one

she had another tap put on the petrol tank too , we cleaned the carb after the first time she droppped revs and this seemed to solve the problem

however riding her home a month ago in the puring rain she cut out and wouldnt start again , thinking she'd seized up i push her home and sat her in the garage to be fixed , but she started on second kick and ticked over perfectly the next day.

last weekend she died and siezed up in the hot weather , we bought a bg bore kit , fitted it and it seemed all ok when i was riding her round the block.

but now the problems back .. she slows down theen stops likes the engine seizes , but then 5 minutes after she kickstarts and goes for another 10 minutes then cuts out and does the same .

anyone think they can help ?? please ?

Sounds like it`s seizing. Try increasing your 2 stroke oil ratio. Also if it has an oil injection pump it could need to bled

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hey

looking for some idea as to what he cause of the engine problem on my bike is .

heres her story

i bought her off ebay , stripeed her down like u do , to refurbish her , as i had her sitting about for a few month before i was 16 . :) ran perfectly afterwards up and down the tracks , when i got her on the road it was winter but i still had 3 onths of bliss . then trouble started.

i first had to replace the fuel filter as fuel was leaking from the old one

she had another tap put on the petrol tank too , we cleaned the carb after the first time she droppped revs and this seemed to solve the problem

however riding her home a month ago in the puring rain she cut out and wouldnt start again , thinking she'd seized up i push her home and sat her in the garage to be fixed , but she started on second kick and ticked over perfectly the next day.

last weekend she died and siezed up in the hot weather , we bought a bg bore kit , fitted it and it seemed all ok when i was riding her round the block.

but now the problems back .. she slows down theen stops likes the engine seizes , but then 5 minutes after she kickstarts and goes for another 10 minutes then cuts out and does the same .

anyone think they can help ?? please ?

Presumably you've gone through the haynes manual and ruled out all of the simple things it could be.

Sorry if it seems patronising but ive had friends who have done this and its just been, lack of petrol, tap off or not on reserve, etc.

Does it sound like its a fuel problem, eg coughing and dieing?

If you just fitted a big bore kit to it have you altered the jets to match? Im not too sure what im talking bout on the subject of big bore kts but i seem to remember reading a forum similar to this and someone replied saying it would need bigger jets. Sounds logical to me as your gonna need more mixture in the barrel to create a larger explosion.

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Presumably you've gone through the haynes manual and ruled out all of the simple things it could be.

Sorry if it seems patronising but ive had friends who have done this and its just been, lack of petrol, tap off or not on reserve, etc.

Does it sound like its a fuel problem, eg coughing and dieing?

If you just fitted a big bore kit to it have you altered the jets to match? Im not too sure what im talking bout on the subject of big bore kts but i seem to remember reading a forum similar to this and someone replied saying it would need bigger jets. Sounds logical to me as your gonna need more mixture in the barrel to create a larger explosion.

we have , she runs hot , but she has done ver since we had her .

she doesnt cough or splutter , just dies . so we ruled out fuel problems first off =/

it had a big bore on it before it seized up , so the jets should be the same but i assume my dad would of checked them after my dad fitted the kit . we just hae little idea about what it is now .

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Sounds like it`s seizing. Try increasing your 2 stroke oil ratio. Also if it has an oil injection pump it could need to bled

thank you .. i think it will be our next try now , though we bled the pump when we did the kit. but wont hurt to try it again.

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whey, another DT owner :P

i've had that problem before, first time it was the jets needed changing up a size and the second my carb was loose and leaking air. so:

1: check your fuel system for loose fittings, leaks, perished seals e.t.c

2: run it up and down the road a bit at full throttle, then cut the engine and coast to a stop, take the spark plug out and check what colour it is on the end (should be a chocolatey brown, but i suspect it will be white and chalky indicating a lean run)

3: take the carb bowl off and tell us what size the main jet is.

also, list any other engine mods you have, the age of the bike, its mileage and preferably a bit about its history, most likely case is that the jets are not big enough causing it to run lean, heat up and ceise

these bikes are extremely hardy and it takes a lot to kill them, i've made some mistakes with mine in the past and ceised it up, blown a big bore kit e.t.c, but with the help of the Yamaha Owners Club i have managed to fix most problems quite quickly :)

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whey, another DT owner :P

i've had that problem before, first time it was the jets needed changing up a size and the second my carb was loose and leaking air. so:

1: check your fuel system for loose fittings, leaks, perished seals e.t.c

2: run it up and down the road a bit at full throttle, then cut the engine and coast to a stop, take the spark plug out and check what colour it is on the end (should be a chocolatey brown, but i suspect it will be white and chalky indicating a lean run)

3: take the carb bowl off and tell us what size the main jet is.

also, list any other engine mods you have, the age of the bike, its mileage and preferably a bit about its history, most likely case is that the jets are not big enough causing it to run lean, heat up and ceise

these bikes are extremely hardy and it takes a lot to kill them, i've made some mistakes with mine in the past and ceised it up, blown a big bore kit e.t.c, but with the help of the Yamaha Owners Club i have managed to fix most problems quite quickly :)

hey oh yeh i love her to bits :) ..

we have problems with the carb anyways , but it seemed that the back brake sticking on and too hot a spark plug was the cause.

we've managed between 5 of us kill one DT :( someone droppped it and it just wouldnt start after that , though it had been modified up to the hilt. lol.

hoping to have a good summer with her before i take my bike test in the winter :) .

thank u .

xx

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hoping to have a good summer with her before i take my bike test in the winter :) .

same here, im taking my full test in october... i sure as hell aint riding through another freezing cold winter on a 50...

maybe some nice heated grips on the jawa, and a screen to hide behind...

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same here, im taking my full test in october... i sure as hell aint riding through another freezing cold winter on a 50...

oh no ... me neither , have my eyes on a pretty 125.. though not the dt .. because i hear they like to blow up alot more than the 50's =/ . dont fancy a winter and summer of constantly repairing the bike again lol .

shame your not a little closer could of had a DT50 mx ride out , every other person i know round here has either an apprillia or a twist and go scooter ... no fun to ride out with . :( although riding with a 1200 bandit behind u is fun =)

xx

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oh no ... me neither , have my eyes on a pretty 125.. though not the dt .. because i hear they like to blow up alot more than the 50's =/ . dont fancy a winter and summer of constantly repairing the bike again lol .

shame your not a little closer could of had a DT50 mx ride out , every other person i know round here has either an apprillia or a twist and go scooter ... no fun to ride out with . :( although riding with a 1200 bandit behind u is fun =)

xx

Blow up! Dt's! not unless you really try. They are real engines! 2 strokes :D so they just love to be ragged....

If they do blow up, its probably because your going 85 with mouth wide open and go "EEEEEEEEEEEEEEE" inside your helmet amazed at what that little 123cc engine can knock out, and forget to take the power off!

As soon as political correctness goes to the next level of madness and allows us to marry machines, im going to propse to a dt125!

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Blow up! Dt's! not unless you really try. They are real engines! 2 strokes :D so they just love to be ragged....

If they do blow up, its probably because your going 85 with mouth wide open and go "EEEEEEEEEEEEEEE" inside your helmet amazed at what that little 123cc engine can knock out, and forget to take the power off!

As soon as political correctness goes to the next level of madness and allows us to marry machines, im going to propse to a dt125!

very true :D

hehe . i could see me doing that ..i ceased my dt50 up like that ... except at 50 lol .... :D

hmm i shall step up to the madness if i can find a cheapy :D

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shame your not a little closer could of had a DT50 mx ride out , every other person i know round here has either an apprillia or a twist and go scooter ... no fun to ride out with . :( although riding with a 1200 bandit behind u is fun =)

just seen your in Beccles, about 190 miles away from me, lol. would wear out a chain and back tyre just getting there.

i often go riding through town with some "mates", usually 2 Peugeot Speedightds, a Yamaha aerox, an Aprillia RS50 and a Gilera DNA and me on my DT (can outrun the lot of them, apart from the Aprillia 'cus thats a six speed ¬¬) and we get our fair share of odd looks,

in my opinion, 125s are just a step up from peds, so its still not as cool as a 400/600 bike. plus i want the power of an FZR400 Exup XD

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just seen your in Beccles, about 190 miles away from me, lol. would wear out a chain and back tyre just getting there.

i often go riding through town with some "mates", usually 2 Peugeot Speedightds, a Yamaha aerox, an Aprillia RS50 and a Gilera DNA and me on my DT (can outrun the lot of them, apart from the Aprillia 'cus thats a six speed ¬¬) and we get our fair share of odd looks,

in my opinion, 125s are just a step up from peds, so its still not as cool as a 400/600 bike. plus i want the power of an FZR400 Exup XD

NEGATIVE!

125's are fantastic as far as motocross's are concerned. DONT EVER COMPARE THEM TO PEDS! :(:P

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just seen your in Beccles, about 190 miles away from me, lol. would wear out a chain and back tyre just getting there.

i often go riding through town with some "mates", usually 2 Peugeot Speedightds, a Yamaha aerox, an Aprillia RS50 and a Gilera DNA and me on my DT (can outrun the lot of them, apart from the Aprillia 'cus thats a six speed ¬¬) and we get our fair share of odd looks,

in my opinion, 125s are just a step up from peds, so its still not as cool as a 400/600 bike. plus i want the power of an FZR400 Exup XD

yup =) lol , back tyre would be fine just the engine would go out.

awh cool yeah aprillas are great fun to ride .. still my dt's better =) .

nahh .. there tons of fun =) yeah they are but i have a 250 2stroke . and thats just hilarious off road :D and on road :D

x

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NEGATIVE!

125's are fantastic as far as motocross's are concerned. DONT EVER COMPARE THEM TO PEDS! :(:P

oh too right :D .. though 250's off road are increased fun :P because you have a little bit too much power there .

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the DT was the first bike i have ever ridden, and it doesnt have the power to pull the skin off a rice pudding... i dout a 125 would be much better. and why bother with one when i can take my full test and hop straight on the jawa? :lol:

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the DT was the first bike i have ever ridden, and it doesnt have the power to pull the skin off a rice pudding... i dout a 125 would be much better. and why bother with one when i can take my full test and hop straight on the jawa? :lol:

obivously yours is a bad egg ... mine goes like hell , the 125's are fantasic even more if you like the bumps :D

and also its good experience. jumping straight on the jawa would kill you on corners.

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the DT was the first bike i have ever ridden, and it doesnt have the power to pull the skin off a rice pudding... i dout a 125 would be much better. and why bother with one when i can take my full test and hop straight on the jawa? :lol:

You have NO idea, try a full power TZR125 and say that. Or better yet a de restricted Aprilla they knock out over 20horses and weight the same as a politicians promise..

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just seen your in Beccles, about 190 miles away from me, lol. would wear out a chain and back tyre just getting there.

i often go riding through town with some "mates", usually 2 Peugeot Speedightds, a Yamaha aerox, an Aprillia RS50 and a Gilera DNA and me on my DT (can outrun the lot of them, apart from the Aprillia 'cus thats a six speed ¬¬) and we get our fair share of odd looks,

in my opinion, 125s are just a step up from peds, so its still not as cool as a 400/600 bike. plus i want the power of an FZR400 Exup XD

Cooo,

you youngsters have not lived !! I rode from Worcester to London every week on an FS1E (good old '76) that journey was 160 miles(ish) and cost about a quid to do (petrol was cheap 72p per gallon or 4.5xx litres) and the 2 stroke oil cost about 10p per shot so whats the problem with it now costing a fiver or so !!!

Regards Jim

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probably because i dont have a job now and my only income is the £5 a week i get form doing oddjobs around the house and for relatives.

i need work :(

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