XR1000 Online Community

Hi,

I'm hoping someone out there can help me idnetify some XR heads. I only have the casting #'s on the heads themselves. This number is the same on both heads and reads 16681 72R.
If anyone has any diminsional spec, that would be helpful as well; then I can measure something to distinguish whether or not they are xr750 or xr1000. Also, would the casting number be the same for both front and rear head? I don't notice any differnce between the two? Any info is appreciated.

Thanks,
Chris

probably you will already know, but as far as I know is your number for XR750, because the ending -72R means its first appearence was 72 and R means for Racing. special XR1000 parts are ending with -83.

best
Andreas

Hi Chris,

this is not right.
The numers in catalog are not the same as inside of the heads.

I just have a XR-1000 head on my desc.
Inside of it there is written your number 16681 72R.

I think the front and the rear are the same.
The only difference is, that the hole for oil draining is at the front or at back.
The front head has the hole at the exhaust side.
The rear head has the hole (for 90° fitting) at the intake side.

Marc

..basically XR750 and XR1000 heads will have the same casting number, cause its the same cast, right?

Greets

Andreas

(Marc, grüß mal Michael, wenn Du ihn siehst...)

I think the front and the rear are the same.
The only difference is, that the hole for oil draining is at the front or at back.

Sorry this is not right, they are different heads, the front and rear head have different positions for the pushrods and covers, this is why it is so important to have front and rear heads as a pair.
Basti

Grüß den Michael auch mal von mir
hier ist es ja voll mit Berliner Xr treibern, da kommt man sich ja ganz einsam vor, ist ja fast schon wie im Sportyforum

The heads are also different FRT to RE as the Exhaust ports are at different angle's. Keep in mind that with Harleys a casting # is not the same as a part #. In 1983 XR-1000 valve size was bigger then the 750's of the day. Though later they did go to the same size. The XR1's should have a pressed in spigot @ the exhaust port that the exhaust clamps to, where on the XR750 the exhaust seats into the head. Putting 750 heads on a XR1 lower is not a problem as long as the frt. port will clear your frt. downtube. Bill/The XRNUT