'89 YZ250 questions

[CoalPilot]

duff,

Only the 88 and 89 engines are the same, the 90 won't work...the cylinder will but the bottom end bolts up different....unless you know a good welder and modify the frame.

[duffysp]

Thanks!!!

[MotoMan]

With a little initiative anything will fit.

[CoalPilot]

You da MAN MOTOMAN! I love the way you think!...........

[offroad101]

from the micro phish that I have loooked at, I have seen no differences from the 89-90 frames. You could always look at some of the websites with the phish services and compare the two.
Ryan

[CoalPilot]

they usually use the same picture for many models. I have learned this the hard way. It may look the same, but if the part number is different, chances are good it will be different in some way. My manual covers 88-93 and 91-93, they use all different pictures when displaying things and always refer you to the tables for your application, the pics are there just to give you an idea of what needs to be done. On some things they may use your exact model but not on others. You can take it from someone who's been there and knows, or you can trial and error it yourself. Your choice.

[offroad101]

he has a valid point, maybe I was not very clear in my reply. Most of the fish have the part numbers attached also. compare the Part numbers, not the pictures
Ryan

[duffysp]

Guys, Thanks for all your replies. I got one additional question. Is it possible to determine the year of a motor by the serial number. For example my 89 YZ250 motor has 3JE-00xxxx. Would any 3JE-00 number be an 89. Thanks again!!!

[CoalPilot]

Yes 3JE is the number for 89 YZ250 and 2VM is for 88.

[Speedfreek]

Hello,
It's good to see a place where the 89 yz 250 is appreciated.I have one that has been rebuilt this winter from the ground up. Any one able to help me post a pic in this message?

[offroad101]

are you asking how we post pictures?
Ryan

[CoalPilot]

offroad101,

I eMailed speedfreek and explained the whole picture posting thing. and that, Also if you do a seasrch, there are threads that explain it too. No need to go write out another long post to rehash a topic that has been explained elsewhere. ()

[Speedfreek]

Thanks coalpilot,you have been helpful

[Speedfreek]

I hate to disagree with anyone,but the crankcase halves are the same from 1988-1993,in 1994 they enlarged the area of the ports entries,which was an internal modification to the engine cases.The points where the engine cases mount are the same from 1988-1996.The cylinder head mount would possibly be different from 1989 to 1990 and newer since in 1990 they changed over to a 125mm connecting rod from the previous 130mm rod which made the cylinder barrel shorter which would most likely affect the top cylinder head mount,which is very easy to modify
Coalpilot,sorry if I stepped on your toes friend.

[CoalPilot]

Not at all, I had steel toed boots on. Ha! Ha! Your right though. I know your experience and value your "insider" knowledge. Sometimes I forget that Dealers feed you B.S. and these young mechanics probably never dealt with the bike. When I say something, it is most likely it is because I did it or was told it by someone I thought was giving me the 'bottom line'. ATM is cool. Together we will all learn and become better riders/builders.

[duffysp]

Guys, Have any of you replaced the steering stem bearings on your '89 YZ250's. Mine are SHOT and the local Yamaha dealer wants an arm and a leg for a new set. Found an aftermarket set on the internet for about $31. I was thinking about checking with the local bearing supply house. They look like standard tapered roller bearings except for the little rubber seal on the top. Any ideas??? Thanks.

[MotoMan]

You should have pretty good luck at a local bearing supply place, I had a friend of mine order a set of head bearings for my '99 thru a supply catalog that they had at work.

Just bring the old one with you, it shouldn't be a problem.

[CoalPilot]

[Only registered and activated users can see links. ]

$27.86 NEW PART NUMBER 93332-00068-00.

But like motoman said if you take the old one with you they should be able to track one down for you at the local bearing supply house. The bottom one needs to be presssed on.

[CoalPilot]

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[CoalPilot]

How is the center post mounted to the lower triple clamp? Is it pressed on, splined, or threaded? I need to take it off but don't want to damage it experimenting.