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Yz 125 blown need help

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Ok so what's up tt traded my 1999 yz 400f for a 2001 yz 125 that was blown. Here's some pics on what the engine looks like. Do I need to split the cases? It's not seized all the gears move, would I be good if I just cleaned out all visible metal? IMG_1480.jpg IMG_1482.jpgIMG_1479.jpg

Also that cylinder is shot I'm already working on getting another

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Split it, clean,  new crank bearings and seals atleast.  Looks like oem crank and being that old a new top end only could be the end of old crank that happens alot. Guy just dropped of a 00' tonight with new top end but bottom gone now

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Split it, clean,  new crank bearings and seals atleast.  Looks like oem crank and being that old a new top end only could be the end of old crank that happens alot. Guy just dropped of a 00' tonight with new top end but bottom gone now

Sigh my fears where true things are gunna get pricey now

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3 minutes ago, brando brap@youtube.com said:


Sigh my fears where true things are gunna get pricey now

Not really if you do it yourself . And it's your call don't have to listen to me ofcourse.  But I see bike engines everyday 

Edited by Motox367

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2 minutes ago, brando brap@youtube.com said:

I will try but it's pretty complicated stuff for a 14 Yearold I mean I've rebuilt bikes before and restored bikes but I mean I need a fly wheel pullers and a lot of specialty tools

Yes you do. Ok when you take cylinder off grab ahold of the piston good and tight with left hand.  Pull upwards on it with that hand. Take your right hand use your palm and hit down on top of piston. If there's play its no good you'll feel or hear clicking sounds.  If not you may be ok for awhile.  But get some weaver brake parts cleaner and not the non flammable crap. Spay crank bearings and bottom rod bearing until clean.  Use air and blow out . Do it few times and after last time you blow when everything cleaned. Use your finger or dripyour favorite twostroke oil on all bearings.  Do that and it may last awhile :thumbsup:

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Yes you do. Ok when you take cylinder off grab ahold of the piston good and tight with left hand.  Pull upwards on it with that hand. Take your right hand use your palm and hit down on top of piston. If there's play its no good you'll feel or hear clicking sounds.  If not you may be ok for awhile.  But get some weaver brake parts cleaner and not the non flammable crap. Spay crank bearings and bottom rod bearing until clean.  Use air and blow out . Do it few times and after last time you blow when everything cleaned. Use your finger or dripyour favorite twostroke oil on all bearings.  Do that and it may last awhile :thumbsup:

I already have all the off I'm the only play with the crank is side to side no up and down and from what I understand slight side to side play is normal

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With that severe of a seizure, if you don't plan on splitting the cases (I would!)

you should at least preventatively replace the left hand crank seal 

or your new piston & cylinder may end up the same much sooner than expected.

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With the amount of RTV sealant visible on the cylinder studs,

I'd also doubt this engine has mating surface trueness issues.

 

With those gouges, at the very least that engine seized once and was later 'un-stuck'.

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Flush the entire bottom end with diesel until it comes out clean with no metal shavings or anything else.

Your crank seals could very well be shot, so don't expect too much.

If you do end up pulling the crank, see if you can borrow a steering wheel puller. They've worked great imo.

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Flush the entire bottom end with diesel until it comes out clean with no metal shavings or anything else.
Your crank seals could very well be shot, so don't expect too much.
If you do end up pulling the crank, see if you can borrow a steering wheel puller. They've worked great imo.

Ok, now everything rotates fine, I've run oil through a few times and seem to only
Come up with once small piece per time and less and less each time I run though is it possible my bearings are in tact

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11 minutes ago, brando brap@youtube.com said:


Ok, now everything rotates fine, I've run oil through a few times and seem to only
Come up with once small piece per time and less and less each time I run though is it possible my bearings are in tact

Honest opinion? Probably not. They might last a little while, but who knows what stuff is in there and has already potentially messed them up. All it takes it for one to go and you'd be right back where you started. If you pulled the crank shaft and felt each one, they would probably feel notchy and shitty, which means time for new ones.

It's possible they are fine. But it's possible they are wrecked and only a matter of time before they let go.

If it were me, I would split them and change them and the seals out, as well as check the tranny and those bearings and gears for any rounded edges. 

At least then I would have the peace of mind that the motor is 100% and the only thing you would have to worry about is a top end in 30-40 hours.

If you can do it yourself, you should attempt it. There are tons of resources and people here willing to guide you through it and help you with every step.

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Honest opinion? Probably not. They might last a little while, but who knows what stuff is in there and has already potentially messed them up. All it takes it for one to go and you'd be right back where you started. If you pulled the crank shaft and felt each one, they would probably feel notchy and shitty, which means time for new ones.
It's possible they are fine. But it's possible they are wrecked and only a matter of time before they let go.
If it were me, I would split them and change them and the seals out, as well as check the tranny and those bearings and gears for any rounded edges. 
At least then I would have the peace of mind that the motor is 100% and the only thing you would have to worry about is a top end in 30-40 hours.
If you can do it yourself, you should attempt it. There are tons of resources and people here willing to guide you through it and help you with every step.

Ok if I did it myself what's the price gauge

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15 minutes ago, brando brap@youtube.com said:


Ok if I did it myself what's the price gauge

Much less as a baseline. Labor is very expensive.

It would depends what needs to be replaced. 

If there is nothing wrong with the tranny and none of the shifter forks are bent, and you are just doing a top and bottom end rebuild, it would be around $175 to rebuild and balance the crank, $50 for crank bearings and seals, and whatever it costs to have the cylinder repaired, replated, and matched to a piston. 

If I were you, I'd split everything down and see how it looks. If the crank is somehow perfect, you'll save some money. Bearings and seals are a must, as well as a top end kit and cylinder replate. Millenium Technologies has good prices and you can purchase a top end kit from them as well.

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Much less as a baseline. Labor is very expensive.
It would depends what needs to be replaced. 
If there is nothing wrong with the tranny and none of the shifter forks are bent, and you are just doing a top and bottom end rebuild, it would be around $175 to rebuild and balance the crank, $50 for crank bearings and seals, and whatever it costs to have the cylinder repaired, replated, and matched to a piston. 
If I were you, I'd split everything down and see how it looks. If the crank is somehow perfect, you'll save some money. Bearings and seals are a must, as well as a top end kit and cylinder replate. Millenium Technologies has good prices and you can purchase a top end kit from them as well.

Ok thanks lmk if you know of any source that I can see that shows me the process I have to go through to diagnose everything

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