Buying second bike for parts

[Ynot]

I will be rebuilding an xs 650 1972. I want to buy an older 650 (1981) for parts.
Are most engine parts , carburators interchangeable.
Maybe I should look for another year for a parts bike.

 

[Jim]

first, welcome!!
The '72 uses a 256 motor... the '81 is a 447 motor. Most parts will interchange. The big difference is the cam and crank. The cam drive sprockets are different. The early motor use 17/34 sprockets and the later uses 18/36. So, you can swap 'em as a set, but not individually. There's other minor differences, but that's the main one.
'72 used BS38 carbs... '81 used BS34's. They'll swap, but you'll also need to swap the intake boots with 'em. 'Course, that old, odds are the boots are shot anyway and need replacing. At least I'd never rebuild one and use the old boots.

 

[650Skull]

I list the changes from the early 70-73 256 models to 447 models on the 74 ID. From 74 to 80 I have listed the changes from model to model.

The change between early 70-73 and 74- 79 standards is they were basically a new bike with little interchangability. Jim points out the cam differences, swapping a 447, (74-84 internals into the 72/73 engine cases can b done but you loose the 256 cam unless the sprockets on the crank and cam are swapped. Standard and Specials, 80-83/4 are basically the same with frame tab differences

https://www.xs650.com/threads/xs650...workshop-manuals-and-other-information.30569/

 

[GLJ]

I will be rebuilding an xs 650 1972. I want to buy an older 650 (1981) for parts.
Are most engine parts , carburators interchangeable.
Maybe I should look for another year for a parts bike.

What do you mean by rebuilding it? All original daily rider, resto-mod or something else?
Take a good look at your bike, are there parts missing if so which ones. Most parts on it are 70-72 only but not all some 70-71 parts will not work, some 73 parts will also work.
Best thing to do is start a thread on the bike. Post pics of it and what you want to do with it and what parts you think you will need.