03 yz250 ?sssssssss

[03yzrider]

well i blew the yz250 up today pretty mad got a couple ?s the last couple days ive been riding it thare has been this noise like klick klick klick and ever time i ride it it just get worse and worse and them she just got (HORRIBLE) VERY VERY LOUD the CAAA BAMM she just bogged down and DIED! but i just wanted to know i took apart the top end and the pition is a little burnt couple nicks in it and the head does not have that bad of scares! please let me know what it could be ganna rebuild the top end forsure just to play it safe but could thare be anything else wrong is my ?

THANKS FOR UR TIME SRY FOR THE LONG LETTER!!!! PLEASE HELP THANKS AGAIN
03yzrider

 

[IndyMX]

Errr.. So it was making a new noise for a couple of rides, and you just ignored it..

Hmm.. Don't stop at the top end. Do yourself a huge favor, tear it all the way down and at the very least inspect and measure everything.

If you don't have one yet, acquire a factory service manual. If you look at the Australian Yamaha Motors website, you can find a PDF version free.

Use that manual to help you do the tear down and inspection. It will have all of the procedures and specs in it.

If you choose to not do this, and just do the top end, make sure you save extra money for when the bottom end does go. It'll probably happen sooner than later. And as a bonus, when it goes, the top end will need to be done again too.

Bottom line is, no one is going to be able to tell you on here what else is wrong with your engine. Only a proper inspection will tell you that. Everything else is just a wild ass guess.

 

[03yzrider]

so what your saying i should tear it all down just to double check everything and can you send me the link to the free sirvice maunel please and thanks and i will reallly do that becuse i dnt want to have to put more money then i should! thanks for your help. and u dnt think i will get away from just top end becuse bottem alone is like 400 man but ill do it.. bu ti will go threw it forsure! thanks please send me the link cannot find the service m!

 

[IndyMX]

Yes, you really need to tear it down. You'll need to inspect every thing and clean out any debris that might have gotten into the bottom end bearings.

http://www.yamahaownershandbook.com.au/lib/download.php?f=5NX-28199-30.pdf

 

[03yzrider]

that link did not get me anywere! and that mean i need crank case pulller right?
and what is the wed site man that link is nothing

 

[expansion chamber]

sounds like the best choice would be to bring it to a skilled mechanic

 

[IndyMX]

that link did not get me anywere! and that mean i need crank case pulller right?
and what is the wed site man that link is nothing

http://www.yamahaownershandbook.com.au/index.php


You'd need a case tool, yes. You can get a harmonic balancer puller from Autozone for about 15 bucks and the proper length / size metric bolts at Lowes for a couple dollars and have what you need.

 

[03yzrider]

skilled michanic. hmm well ive done alot of my own work on bikes but never bottom end and yes a skilled michanic would be great but to much money! thanks for all the replys ill get it done and bottom end is onley 300 bucks for my bike and thats for hot rod crank.. thanks guys for your time and help!

 

[IndyMX]

You may not need to replace parts. But you won't know for sure until you follow the proper procedure in inspection and measurement.

Best case, you are only out a little time and effort. Worst case you have to replace some bearings and a crank.

When you realize how simple the job really is, you'll be glad you have that extra peace of mind knowing your crank isn't going to extricate itself from the cases mid flight off a jump.

I've never had that happen, however, it just doesn't sound like the best way to end a day of riding.

 

[oldguy]

skilled michanic. hmm well ive done alot of my own work on bikes but never bottom end and yes a skilled michanic would be great but to much money! thanks for all the replys ill get it done and bottom end is onley 300 bucks for my bike and thats for hot rod crank.. thanks guys for your time and help!

You really could have saved yourself a lot of money if you would have done the smart thing and stopped riding it when it told you to (you know that sound that you ignored)

Maybe next time :nod:

 

[IndyMX]

You really could have saved yourself a lot of money if you would have done the smart thing and stopped riding it when it told you to (you know that sound that you ignored)

Maybe next time :nod:

Read my tag line.. That explains everything.

 

[03yzrider]

i am tellin you but screw it at least i will know my whole motor ive never rebuilt this bike but rebuilt my 04 cr 250 but crap happends RIGHT? but ill go threw the motor before anything.

 

[oldguy]

i am tellin you but screw it at least i will know my whole motor ive never rebuilt this bike but rebuilt my 04 cr 250 but crap happends RIGHT? but ill go threw the motor before anything.

I don't have my secret decoder ring and my head hurts to much to try understanding that post without it :whoa:

Really you would look better and get better help if you took time to type in a language most of us are fluent in

Good luck with the rebuild 2 strokes are far easier (and less expensive) then a 4 stroke at least

 

[IndyMX]

I doubt a spell check would even be able to sort that out.

I was only really guessing at the original intent of this thread.. Hope I got close to what he was after.

 

[03yzrider]

sry ha i was typing very fast and 1 of you guys said u should have stop riding it and i said i know i really should have not been riding it and then i said i kinda just want to rebuild the whole motor so it can be new again. (I doubt a spell check would even be able to sort that out.) lol that funny! sry guys haha just typing fast but thanks for ur guys is help.

better?? lol

 

[03yzrider]

and the sound just got really bad.I had to get home some how so i decided to ride it. but pretty stuiped but atleast freash motor for summer!

 

[oldguy]

and the sound just got really bad.I had to get home some how so i decided to ride it. but pretty stuiped but atleast freash motor for summer!

and a good feeling once it is done :cool:

 

[03yzrider]

haha but the funny part is i NEVER GOT HOME haha she let me down.. yes very good feeling! haha

 

[IndyMX]

I think it's an unwritten rule somewhere that a bike will never ever break at home. Or once it gets home.. It will always break at a point where you have to walk a considerable distance.

Murphy is a jerk. (cleaned up for the kiddies)

 

[03yzrider]

yes

 

[julien_d]

Sounds like the piston shattered. Have you only removed the head and looked at the top of the piston, or have you pulled the jug so you could get a look at the piston skirts? Seems like what you were hearing was piston slap, and ignoring it gave the skirts enough time to become fatigued and shatter.

I've heard of this on several yz250's. I think your best bet is to run a forged piston in a yz250. Tearing it all the way down is indeed the best course of action. There could be little bits of piston down there in your crank bearings!

 

[03yzrider]

I tore the whole jug down and like i said the pistion was not horribel but thare were some scares. pistion did not shatter i looked and the whole pistion top to bottom... it was a very loud knocking at first you could not really here it but i got VERY VERY LOUD when i was riding it the sec time it was bad i could bearley here my bike just the knocking

 

[Porkchop]

You were more than likely listening to your lower rod bearing morphing it's self into shrapnel. Buy a pile of new parts, gaskets, other special tools & some new air filters.
A bit of wrenching, re-plating, re-assembly & you will have a chance to wear it all out again! Be certain to make sure your air box/filter/boot/intake tract is all sealed up.
Good luck...... :ride:

 

[03yzrider]

so ur saying that if i do rebuild the bottom end and top it is not goin to really do anything for me?? its just goin to keep happining? and i really think thats what i could be!

 

[ellandoh]

he's saying it will all be fresh and ready to ride for a long time (with regular maintenance) so have fun wearing it out again. and mentioned the air tract as he probably suspect reason for failure was contaminants