Hi, New here. Question?

I have a 82 Seca that came with a spare engine. One engine has black jugs and alum valve cover. one has silver jugs with black valve cover. Whats the blackened part difference in these engines? Does the black valve cover go with the engine with the black jugs or? thanks for any info

 

Sorry it's the Xj 750

 

I'm pretty sure the only difference is the paint.

 

If they are both from Secas, they are from different years of Seca but I'll be darned if I could tell you which. If I recall correctly, Chacal did post the paint "code" on a thread but I can't remember which it was.
Parts will swap without issue.
If the motors are off of different models (Maxim and Seca), you will need to match up displacement in order to swap parts. 650 parts and 750 parts are not the same except for the alternator and starter.

 

Thanks Big ans Robert, i guess their both off 750s must be different yrs.

 

If by "engine" you mean "engine and transmission" then the serial number of the original bike will be stamped on the transmission. From that number, we can tell you what kind of bike it came from, displacement, year, etc.

It will look like this: 5N8-012566

Obviously, none of those exact digits will match your engines, but that's what the S/N looks like. It's a partial VIN.