2000 yz 125 in need of a new top end and making weird noises

[lazywaffleman]

Im getting a new top in put in but what would explain the duck like sounds?

I have a video of it but it wont allow me to post a link

 

[2strokerfun]

Hmmm, if it sounds like a duck.......

 

[whenfoxforks-ruled]

Hello and welcome! Do you have a manual for the water fowl? Vintage Bob

 

[lazywaffleman]

Well, i have the manual for it. I have a video that I would post but it wont allow outside links.

Also I trying to find out if it is in fact a 2000
Where is the vin located?

 

[whenfoxforks-ruled]

You have to have so many posts before that privilege works, and is refundable. Vintage Bob

 

[lazywaffleman]

Im trying to find out where the vin is loacated to see if it is a 2000, can anybody help?

 

[whenfoxforks-ruled]

My Cr250 had no tag on the frame, but I knew its a 97. The engine id numbers, I called American Honda, they know every casting marks id! Vintage Bob

 

[lazywaffleman]

found the vin, heres it is

JYCED5C5YA012339

what year is it?

 

[whenfoxforks-ruled]

"10th digit applies to ALL Japanese dirtbikes", after a little searching? So its a 1980? Big difference there! I knew the 10th digit as a Honda thing? Does the engine and frame vin match? Vintage Bob

 

[MXSparx]

I think the VIN should be 17 digits and on the frame at the steering head or steering tube below the bars on right side

 

[lazywaffleman]

Weird, I got the vin right off of the steering head. Well I would add a picture or video but i cant. When can get the ability to do that?

Heres the corrected vin
JYACE05C5YA011339

 

[MXSparx]

2000
10th digit is y=2000

For example: 1988(J), 1989(K), 1990(L), 1991(M), 1992(N), 1993(P), 1994(R), 1995(S), 1996(T),
1997(V), 1998(W), 1999(X), 2000(Y)
2001(1), 2002(2), 2003(3), etc.

 

[lazywaffleman]

ok, now thats solved

If you search "Yamaha yz 125 Bad top end" on youtube it is the first result. Tell me what you think the duck like noises are from

 

[ellandoh]

blow by;

sounds about right for a 0psi compression top end

 

[lazywaffleman]

What would cause something like this?

 

[ellandoh]

part of the regular maintenance on a 2stroke mx bike is a complete top end rebuild. which can be done thoroughly in about 2 hours once you get it down .

the answer is, do the top end before you attempt to start it again. maintenance has been slacked.

 

[lazywaffleman]

Thank you, bike was given to me from a friend that doesnt ride and didnt take care of the bike. Btw it sat in storage for 3 years

 

[whenfoxforks-ruled]

It would be ideal to take the engine all the way down, replace all the seals and bearings. Kits can be had for under a couple hundred. By then, replacing the crank and top end for sure. I am guessing 5~650 dollars you will have a fresh engine and KNOW everything is in spec. And start counting hours of run time. Vintage Bob

 

[lazywaffleman]

Would i need to break the engine in again?

 

[_JOE_]

Yes, you would need to go through a break in on new bearings. It's even more important that the bearings are broken in properly than the top end.

 

[lazywaffleman]

Alright thank you,I took the bike into the local shop and im have a new top end wiesco kit put in and they checking everything to see if anything needs replacement.



http://www.youtube.com/watch?v=d2NYokFFBJU

 

[lazywaffleman]

The shop called today and they said the engine was fubar.They ordered the parts. They also said they the cylinder was pretty messed up and they are over boring it or something. Basicly im getting a new engine when everything is done.......... In 3 weeks
:bang: