OzVMX Forum

Marque Remarks => Yamaha => Topic started by: rocketfrog on February 05, 2013, 02:34:54 pm

Title: 1992 yz250 chrome bore or not?
Post by: rocketfrog on February 05, 2013, 02:34:54 pm

Does anyone know if the YZ250D1 (1992) has a chrome bore or conventional liner. Which year did Yamaha switch to Chrome bores on thier 250's (2 strokes) anyone?

Title: Re: 1992 yz250 chrome bore or not?
Post by: ash666 on February 05, 2013, 03:28:12 pm

 THE 1989 YZ "w" WAS THE 1ST YZ125 WITH A CHROME BORE SO, I'M PRETTY SURE THE SAME APPLIED TO THE YZ250

Title: Re: 1992 yz250 chrome bore or not?
Post by: steveo247 on February 05, 2013, 11:14:15 pm

no chrome bore on my D1

Title: Re: 1992 yz250 chrome bore or not?
Post by: evo550 on February 05, 2013, 11:45:20 pm

They were chrome and had three different colour codes to match piston/cylinder size, usually a dot of paint on the back of cylinder above the reed cage.

Title: Re: 1992 yz250 chrome bore or not?
Post by: Ando on February 06, 2013, 04:47:25 am

Yes, the 89 YZ125W was the first of the chrome type bore! It wasn't until 91 the YZ250B1 was the first of the chrome bore. To prove this look at the pistons listed for the prior 250's 0.25, 0.50, 0.75mm oversize.

Title: Re: 1992 yz250 chrome bore or not?
Post by: steveo247 on February 06, 2013, 09:18:12 am

Quote from: steveo247 on February 05, 2013, 11:14:15 pm

no chrome bore on my D1

Idiot!! bad info! too many bikes  ;D i should check instead of thinking i remember everything.

Title: Re: 1992 yz250 chrome bore or not?
Post by: whitey 43 on February 06, 2013, 01:40:06 pm

Ando's spot on-chrome bore started in 91 (250)
Unless its already been resleeved...

Title: Re: 1992 yz250 chrome bore or not?
Post by: rocketfrog on February 11, 2013, 01:32:22 pm

Yes I believe this cylinder has been resleeved if the brains trust confirm this model was Chrome Bore as per OEM.

Thanks for the help guys, by the way will the seat from a WR 250 (1992) fit the YZ? I see it comes up as a different part number but is that just colour or is the geometry different also?

The reason I ask is that my seat base has been repaired over and over and now needs a new cover, which I believe is the only thing holding it together at the moment. I thought that I might increase my chances of finding one if WR was compatible.

Title: Re: 1992 yz250 chrome bore or not?
Post by: steveo247 on February 12, 2013, 11:55:24 am

I believe my seat is off a WR. not sure if off a 92 or 93.
I cant remember the number stamped into the base of the seat, i could take it off and look if you like.

I didnt bother to check it was actually the correct seat as when i got the bike, i only realised something was wrong when i got the new cover.
I'm not fussed, it looks worse in these pics than it does in life. If i come across a cheap correct one ill swap it over.

(http://i389.photobucket.com/albums/oo331/steveophotos/yz250d1/20130212_113859_zps0398be16.jpg)
(http://i389.photobucket.com/albums/oo331/steveophotos/yz250d1/20130212_113852_zps96c1d5c1.jpg)

Title: Re: 1992 yz250 chrome bore or not?
Post by: steveo247 on February 12, 2013, 11:56:23 am

it would actually fit alot better if i didnt really stretch the pink cover to fit to the seat. you can see how it has lifted the back part up and out of shape.

what it looked like before i made it bow -
(http://i389.photobucket.com/albums/oo331/steveophotos/yz250d1/09122011561.jpg)