Matching frame ID to engine type?

[wojski]

Hey guy,

Sorry if this is a basic question. Im in Australia rebuilding an XS650. Im looking at buying a used crank online. The seller is unsure if if it is a 256 or 447 engine it is all in bits and he can not figure it out (he sells thousands of bike parts) he does however have the frame it came out of the ID is 3G0-005716. I checked on biker.net apparently its a XS650G 1980 Special II. That part Im not too concerned about...

The seller is based in the U.S. I just want to know if it is a crank out of a 447 motor so it will fit. How can I find out? all U.S models are 447 aren't they?

 

[grepper]

256 is 1973 and before. 447 is 1974+

 

[gggGary]

XS-G 79-80 3G0 3G0- 000101

That makes it a 447

 

[wojski]

Wow, awesome. Thanks for the super quick replies guys. I appreciate it. Time to start purchasing

 

[xstra]

why not look around in europe for a 533 crank-has longer rods...140mm

 

[wojski]

why not look around in europe for a 533 crank-has longer rods...140mm

What other modifications need to be done to fit a 533 crank though?

 

[XSLeo]

The connecting rods have the series number right on them. A 256 will say 256 on it, a 447 will say 447 on it. You will see it in a pic of the rods showing the sides of the rods. I assume a 533 rod is the same way.
The 533 rods being longer, the piston height from the piston pin to the piston top will be shorter. You will need the 533 pistons to run the 533 rods.
I think the cam chain sprockets are the same on the 447 and 533 engines, the older 256 use different sprockets and cam chain.

 

[wojski]

Interesting. I am looking at running Mikes 750cc kit. Im thinking sticking to 447 will make thigns a whole lot easier for me in the long run.

 

[xstra]

Heidens 750 kit comes with whatever pistons you want, the cylinder is the same, you simply need to tell him what crank you have. The rods are forged with 533 on them and are longer. They are also not open at the big-end as theyre not primarily oil spray-fed like the 447 and 256 rods, instead being scoop fed - the pins and crank are so formed to feed oil to the big-end. Better oil feed, somewhat less vibration, piston spends less time at TDC-BDC.