interchangeable heads.

As has been stated, the heads will direct swap. The cam sprockets are totally irrelevant unless you are swapping cams without changing sprockets. 79 motors up to a certain serial number had the 15th crank and 30th cam sprockets [LTD for example had those motors]. Double check things if you swap cams as well.

One important thing to note as well and hasn't been brought up. If you go swapping internal parts such as valves, you need to pay attention to the valves and the guides.

In 79 Kaw switched to cast iron guides and changed valves as well. You can use OEM valves from a cast iron guide head in an older head with bronze guides BUT you can't swap the other way....old valves in a newer [cast iron guide] head. For example you wouldn't want to put OEM KZ900 valves in a newer head with cast iron guides. They are the same size but NOT the same material.

Chances are you'd just go with aftermarket valves anyway but hey....ya never know what someone will try to run....

Post edited by: larrycavan, at: 2007/01/19 21:52

really,well then i have an mk11 sitting in my garage that i am not sure what size motor it is. is there a place i can run engine numbers? i need to find out which size it is.

Look on the front of the cylinder on bottom...I think on lower right corner, and it will have the cc size stamped in block. Engine number aboce clutch cover will tell what you have, but I don't know where to go to tell, but I am sure someone on here does. Check your cc number on block.

it clearly has kz650 stamped on it. now let me make sure i am not mistaken here, mk11 heads are more squared off than the old, round styled heads correct?

I may be wrong here, but most later 1000cc motors had the square valve cover ends. The round style will interchange though. Kz650 has the square valve cover ends too...can you post a pic of the motor you are talking about?

let me take a picture and i will post it.

here we go take a look at this.




and another.

That's most definitely a KZ650 motor but that's not a NK11 valve cover. I will try to add a valve cover that would be on a MK11. You will notice it doesn't have the bolt in the end of the cover. Your's is sorta squared off, but you can see the difference. A j head looks somewhat like yours but it is different from yours too. Look at the pictures and you will see. Motor in blue bike is a MK11 style motor and valve cover.

Post edited by: racer54, at: 2007/01/19 23:38