Topic: Correct Exhaust for 3/70 CB750K0

[Ujeni]

Ok, time to track down the correct exhaust for my March 1970 CB750K0. The common wisdom is that a set of HM300 pipes would be correct. But I have read that the "no number" pipes were used up into the 1035000 VIN range (mine is 1028xxx). Does anyone know for sure which set would be correct? Is it possible that both would be correct...that Honda was using both types for the K0?

[Old Scrambler]

I have no direct knowledge of the exact change-over.  I would go with the 'no-number' pipes based on the collective hear-say and the thought that your motor may be from the original factory. My 6/70 K0 had HM300 pipes but my original sandcast and my #1010xxx had/have unstamped pipes.

[dhall57]

My 4/70 KO as far as I know has the original HM300's and they are stamped. Frame vin is in the 1031XXX range

[Ujeni]

Very interesting dhall57. Our VIN numbers are close...so that leads me to think that the HM300 stamped exhaust is correct. Has anyone seen a lower VIN stamped HM300 or a higher VIN non-number exhaust?

Another question, has anyone had experience with the replica pipes sold out of Vietnam? Here's a link:

http://www.ebay.com/itm/200847415421?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648

I emailed the seller and he says he has sets with and without the stamp...and he can have the baffles painted correctly. I would prefer to go with Yamiya pipes, but they appear to be out of stock.