Engine VIN number does not match? KZ400?

Hey all, it's a 1976 KZ400D (as the title says) but the VIN on the engine does not match. Did they match back then? On the neck it's K4-520764, and the engine is K4E 069595. This confuses me because from what I can find, there was no such thing as a KZ400E model, so that's ruled out.

I wasn't sure where to post this, so I put it here. Please redirect me if needed.

The engines and frame (VIN) very rarely match on a KZ. The only time I have seen one match was on a bike that was built the first day the model was introduced. After that they get out of sync very quickly. Also, the letter in the engine code doesn't necessarily correspond to the letter in the VIN. Ed

CycleChaos.com has the engine & frame number info for many Kawasaki models.
Zedder.com is another place to check.

Yes, this 'matching numbers' thing is a myth on most zeds.

My GPz550 frame 000022 had 000029 motor, higher up in the numbers the variance increases...that is assuming you still have the original motor in there.

If those numbers are the same as the Z1's then you do not have a matching engine/frame. The acceptible difference (with Z1's anyway) is around 200-ish between the frame and the engine to be considered "matching numbers"

Your bike is way off. I would guess the used an earlier replacement case which would be numerically lower. Or someone swapped engines.

I don't think your bike is a 1976 model. It probably is a 1977 model. Titles are often wrong. Does your steering neck still have the label that shows the build date? Ed

The E in the engine number just denotes that its the um... Engine number.

Just like on the Z1
Z1F- frame number
Z1E - engine number

And no, engine numbers usually dont match but would be right. My bikes are all way off. Many have engines that 'arent right' because the factory changed them or they were defective and changed out.

Sometimes the numbers are way off because more than one model in the same year used the same engines, and Kawasaki did not start another sequence of engine numbers for the second model. As an example - the 1977 KZ650-B1 and KZ650-C1 all use the same engines and there is only one sequence of engine numbers. So my KZ650-C1 which has a VIN (frame) number lower than 2,000 came with an engine with a number greater than 24,000. In the case of the KZ650-C1 bikes they all have engine numbers many thousands higher than the VIN because the C1 model was introduced later in the model year than the B1. Ed

The carb/airbox match a 1976, the steering neck does have the numbers but I don't have them right now (at work).