OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Slakewell on June 29, 2010, 10:14:45 pm

Title: What spec were YZ D forks?
Post by: Slakewell on June 29, 2010, 10:14:45 pm

These dont look right to me?
http://cgi.ebay.com/ebaymotors/1977-YAMAHA-YZ400-YZ-400-D-FRONT-FORKS-250-/280385106744?cmd=ViewItem&pt=Motorcycles_Parts_Accessories&hash=item4148413338

Title: Re: What spec were YZ D forks?
Post by: TT5 Matt on June 29, 2010, 11:50:56 pm

yz's had 38mm tubes/air caps and IT's had 36mm tubes and no air

Title: Re: What spec were YZ D forks?
Post by: motomaniac on June 29, 2010, 11:55:42 pm

what doesn't look right?

Title: Re: What spec were YZ D forks?
Post by: Davey Crocket on June 30, 2010, 07:06:38 am

For a start old mate says there 40mm tubes.....

Title: Re: What spec were YZ D forks?
Post by: JohnnyO on June 30, 2010, 08:14:45 am

There are no 40mm forks on Jap bikes. They look right for the period but maybe IT forks.

Title: Re: What spec were YZ D forks?
Post by: Nathan S on June 30, 2010, 09:14:53 am

A big hint is the single 8mm (12mm head) pinch bolt on the axle. That only existed on YZ250/400 D/E/F forks.
The way to tell between the three year models of forks, is to look at the underhang of the fork leg below the axle.
These are 250D forks:
http://i46.photobucket.com/albums/f128/annaandnathan/Bikestuff/Photo0158.jpg
The 250E forks have a second dummy dimple above the oil drain screw, and more underhang.
I'm pretty sure that 250F forks have a longer underhang than the D forks - VMX #33 or Google will be able to confirm.

These arre not IT forks. By the time the ITs got 38mm forks (1981), they had the seperate axle clamp plate that's held on by four 6mm studs.

So... I wouldn't be the house on it, but I reckon they're D forks.
An overall length measurement would help too.

Title: Re: What spec were YZ D forks?
Post by: Slakewell on June 30, 2010, 09:39:20 am

They appear to be correct except the 40mm stuff I have ask him to check them again

Title: Re: What spec were YZ D forks?
Post by: motomaniac on June 30, 2010, 12:40:23 pm

Nathan is correct . only D forks had that pinch bolt AND the single oil drain lug. E are similar but the slider is extended 20 further below the axle for more overlap -hence the second lug and the oil drain moved lower.F's have the same lowerslider as E 's but the chrome leg is longer.
They are 38mm until the H's they are 43mm .Whoever has the 40mm forks tell him I got $500 for them,he can spend it on the drugs that he must be on..
IT forks are 36mm for that era and have the drain hole on the side like YZ125 with 36mm.

Title: Re: What spec were YZ D forks?
Post by: Slakewell on July 03, 2010, 12:11:18 pm

He has checked them again and tells me there 38mm so I have purchased them for $195.00 USD deliverd with triple clamps.

Title: Re: What spec were YZ D forks?
Post by: E74 on July 03, 2010, 02:18:26 pm

I have a set for $100  :-\

Title: Re: What spec were YZ D forks?
Post by: Slakewell on July 03, 2010, 02:59:03 pm

Now you tell me  :D  I did post in the wanted section can you PM a pic of them?

Title: Re: What spec were YZ D forks?
Post by: Slakewell on July 03, 2010, 05:42:40 pm

If you have a wheel to suit that would be handy?

Title: Re: What spec were YZ D forks?
Post by: motomaniac on July 03, 2010, 07:14:04 pm

here are some IT forks from that era -36mm with the oil drain on the side .

http://cgi.ebay.com/ebaymotors/1977-YAMAHA-IT250-250-FRONT-FORKS-175-400-YZ-TRIPLE-/280528752131?cmd=ViewItem&pt=Motorcycles_Parts_Accessories&hash=item4150d10e03