Missing engine numbers

[sharpeyie]

HI all.

Recently bought a 1975 Z1B that has no engine number on it. It was brought in from the states in 1999 it seems, the frame number is there and tallys with what is on the reg. document, but the upstand on the crankcase where the engine number should be is present but completely blank. Even the the '903cc' marking on the barrels is there! Has anyone come across this before that can explain WTF happened with the engine number?

It’s not the end of the world as I’m not looking to resell at profit, but I would like to know what the story is.

Thanks.

[Julian_Boolean]

Japanese Domestic Market bikes often don't have engine numbers

[warren3200gt]

Does the bit where the engine number should be still have a ridge around it? Tha t ridge should still be there even if it was never factory stamped as its part of the case casting.

[sharpeyie]

Japanese Domestic Market bikes often don't have engine numbers

But the 900’s were always too big for the Japanese domestic market surely... ?

[sharpeyie]

Does the bit where the engine number should be still have a ridge around it? Tha t ridge should still be there even if it was never factory stamped as its part of the case casting.

There is very clear and unmistakable ‘plinth/upstand’ on the crankcase above the clutch, absolutely where it should be - it is flat and smooth. Just the numbers themselves are missing.

[compo z1r]

Replacement casing or engine check for warranty replacement if u have full history I’ve bought a brand new un stamped frame in the 90’s they just come with part No sticker tag that’s how kwak sold them

[sharpeyie]

Replacement casing or engine check for warranty replacement if u have full history I’ve bought a brand new un stamped frame in the 90’s they just come with part No sticker tag that’s how kwak sold them

Right. Sounds reasonable I guess. Thanks for that.

[sharpeyie]

I found this on ebay just now - this is exactly how it looks .....

[zed1015]

I found this on ebay just now - this is exactly how it looks .....

Numbers have been removed.
Only the early short number blocks were plain flat.
The later, longer ones have a raised ridge (fence) around the edge of the block which has gone and it's also plain to see that the height of the block on the ebay cases is a few mm lower and the top surface closer to the case than normal..

[sharpeyie]

I found this on ebay just now - this is exactly how it looks .....

Numbers have been removed.
Only the early short number blocks were plain flat.
The later, longer ones have a raised ridge (fence) around the edge of the block which has gone and it's also plain to see that the height of the block on the ebay cases is a few mm lower and the top surface closer to the case than normal..

The seller said he felt that had been done but wasn’t sure why. He felt it might have been to disguise the size of the engine in some racing scenarios.

Hardly gonna enhance the value by making it totally anonymous...??

[warren3200gt]

Zed1015 is correct and what I was trying to describe in my earlier post. As per pic below. Being the suspicous type without that ridge I would be thinking the numbers have removed from a nicked and parted out bike.

IMG_20200520_230540.jpg (88.33 KiB) Viewed 3241 times

[zed1015]

The engine number really bears no relation to the size of the engine in a racing scenario except to denote which model of 900 or 1000 the cases initially originated.
The lack of numbers isn't really a problem unless you are in it for the money and the reason for their absence is anyone's guess.
If you have engine numbers on the V5 then just get some stamps and put them on the cases yourself.
If not leave it blank or buy some cases with original numbers on and get them put on the V5.

[compo z1r]

I found this on ebay just now - this is exactly how it looks .....

Kawa deffo sold frames and casings new un stamped for replacements but that’s a ringer

[rpeters]

Yep, thats been removed, I had a replacement engine which was un-stamped, see pic below

IMG_0370.JPG (51.47 KiB) Viewed 3226 times

[sharpeyie]

Guys, thank you all for your contributions.

I think the consensus has to be that they have been removed (even though numberless cases can/could be bought from Kawasaki they would have the upstand on the plinth.) Ah well.

Mystery solved. Really appreciate your help.

Thanks.