CB750 engine with blank engine number- What does it mean?

[ChuckW]

I just got a Honda marked 1975 CB750F on the frame.  The engine is blank where the serial number should be.  What does this mean?  Is the engine more valuable because the engine cases are blank?
Thanks in advance for any info.  

[Rod_Knockin]

Im not positive but I would guess that the case was replaced. Possibly been in an accident that cracked the case and then the case was replaced with an OEM replacement part.

[Rick V]

 I have to agree with Rodaknockin,I replaced a few sets of cases for various reasons and never restamped the numbers. More valuable? Probable not because it is not original. Honda would not miss something like that.

[gonebiking-2]

I tend to agree with the replies from the other two who have responded to your question. I doubt that Honda would put out an engine from the factory with out an engine number on it. Possibly someone changed the motor using a casing that no one botherd to stamp the existing enegine number off the orignal motor. Do you know what the frame number is - as I might be able to help you with an engine number from an old 1981 CB750K thats sitting in my shed beyond total repair

[cbrreg]

Hi I bought the cb750 f2 engine,but didnt realise that the engine number had been removed until the following week when i decided to strip the engine down for inspection and dont know the frame number.my fault i should of been more vigelant.dont know of anyone who re-stamps engine numbers.(DO YOU).Regards.

[TOOLS1]

The bikes are titled to the frame number. Also the engine, and frame numbers do not match, so I would not worry about it. You might be better off with the blank cases. If numbers are stamped onto it, it might look like it was tampered with.
TOOLS

[scarab2300]

You have a case with no number because Honda would replace broken cases due to chain breakage.The early  chains could not handle the power of the early CB750's & these were replaced under warranty.It was up to the Retailer to restamp the case with the old number before installation.In turn the Retailer would drill through the old number once the cases were changed.It matters not-the VIN number is always the important number as it tells you what model the bike is.Rick.

[cityslicker]

The frame and engine number never matched ever? Oh man, thats cool. I was wondering why mine didn't match, I just assumed it had been replaced.