Topic: CB750 engine serial numbers

[Nortstudio]

I just picked up a parts bike with a pretty slamming engine.  It's a 750, but I'm having a hard time figuring the exact year. The engine has the number CB750E-25xxxxx.

I thought it was a 1976, but all the charts I see list '75 as 24xxxx and then don't list anything until 27xxxx in 1977. Does this number say it's a 1976?

Thanks so much.

[Gordon]

Did you see this chart on sohc4.net?

http://www.sohc4.net/index.php/archives/111

[Nortstudio]

Yep. That's what I was going off. Also checked on cycle chaos. Am I missing something here?  There is no mention of 25xxxx at all. It goes from 24xxxxx to 27xxxxx. There is also on year that appears to be left blank.

[david 750f]

The 25***** engine numbers are from the 1976 F1's. You probably have an F motor.

http://www.sohc4.net/index.php/archives/36

[Nortstudio]

Thanks guys. The only thing that confuses me is that there is no F before the E in the serial number. I saw that 25xxxx was listed for the F - and I assumed that was it, but when I double checked, I saw that my serial is: CB750E 25xxxxx

[david 750f]

Nortstudio, no F in my engine serial number. It is definitely the original engine.
I have not seen a CB750F engine with the letter F in the engine serial number.
I just checked my original Honda parts list for my 1976 CB750F and they show a F in the VIN number but not for the engine.

David

[Stev-o]

Nort - what are you going to do w/that motor?

[CycleRanger]

Did you see this chart on sohc4.net?

http://www.sohc4.net/index.php/archives/111

http://www.hondachopper.com/engine/engine_timeline/timeline.html

This one lists 25xxetc. engines.

[Nortstudio]

Awesome, thanks guys.  I think it was cycle chaos that threw me off, mentioning the FE preceding the numbers.  Sorry to be a pain....

The whole thing is being sold (except for a very few odds and ends that I will keep for myself).

Tango has dibs on some of the stuff, but I will be listing it all here first, as soon as I can get photos up.

[754]

Being that you did not know what it was, what makes it a "slamming" engine ??

 Does it have studs on the exhaust ports..?

[Nortstudio]

Good point, I should have been more specific.  I meant "looks" slamming.  It's about 75% cleaner than the way the engine on the '76 550 Looked when I first got it. I should have said it looks clean.

I was pretty sure I knew what I had - but the confusion came from the listing of an engine number with an F in it, on the cycle chaos site.  And although I have not dug into it yet, I have high hopes....