74 MX250 rear sprocket

[rudymx250]

I've been to the local Yammie dealer, they say it's been discontinued. I've tried to cross ref it on JT sprockets and found that it's the same as the YZ250 up to 97. I've measured the sprocket and from what I can tell, the measurements don't jive with what JT is saying it should be.

Should be about 110mm from opposing bolt to bolt (JT says 175) and the inside diameter should be about 85mm (JT says 152). WTF?? :whoa: Am I just on crack, or what?

Any ideas? Or is the problem that I don't have a stock wheel? Whatever it is fits up to the rest of the rear axle parts that I've bought to replace what was missing when I got it (brake plate, spacers, adjusters).

 

[fatboy570]

Rudy, try this number. 417 258 2544. Ask for Brian in parts. He has been able to find sprockets for my 73 MX 250, maybe he can help. You may have to go with aftermarket, such as Renthal

 

[pryor]

The sprocket from a 73mx is the same as a 74mx, I have a 72mx360 and a 74mx360 and they use the same rear sprocket. I don't have the measurements but 85mm sounds right for the center hole.

 

[Vintagesplash]

If you are still having trouble, Parts Unlimited makes them. Here is the info from Dennisk Kirk:
$36.95 Parts Unlimited Sprocket
Dennis Kirk Part #: 818851S
Manufacturer Part #: CT24351S
Chain Size: 520
No. of Teeth: 51
Position: Rear
Type: Sprocket - Steel
Units: Each