Honda CB750 Sandcast

The Restoration Shop => Exhaust => Topic started by: Steve Swan on February 17, 2010, 12:01:18 pm

Title: Exhaust Pipes
Post by: Steve Swan on February 17, 2010, 12:01:18 pm
Eli's comments & questions have got me on a roll.

I contacted the Ebay "K0" seller. The pipes have "HM300" stamped in them, with NO relief or "indent."

Seems like i heard somewhere, at some time, from someone of "stamped" HM300 pipes WITHOUT relief.

Does this mean there may actually be 4 different types of exhaust?

1. "Plain" or unstamped exhaust with NO relief.
2. "Stamped" HM300 exhaust with NO relief.
3. "Stamped" HM300 exhaust WITH relief (original issue)
4. "Stamped" HM300 exhaust with relief made at a later production runs?

My 4363 has the exhaust mentioned in "4" above. They also have some jibberish i cannot recite, that is stamped on the inside of the exhasut toward the rear of the muffler, about not meeting EPA standards after 1983

Per above the "#3" exhaust don't have the EPA jibberish.

Per above, the "#1" pipe, we all revere, cherish & love.

But, the "#2" pipe - seems to be a bit of a conundrum - perhaps ? Maybe this is a Honda replacement pipe of a slightly later production run, prededed only by the "#1" pipe ?

Hmmm........ Great contorversy !
Title: Re: Exhaust Pipes
Post by: 736cc on February 17, 2010, 12:01:51 pm
There were early unstamped pipes, too. No indent on #1 pipe and strange looking baffles.
Title: Re: Exhaust Pipes
Post by: Steve Swan on February 17, 2010, 12:02:10 pm
Andy,

Were the exhaust you are referring to i.e., unstamped, no indent, "weird" baffles, used on Pre-Production models ?

Or, are you saying these exhaust were used on Production models ?
Title: Re: Exhaust Pipes
Post by: 736cc on February 17, 2010, 12:02:24 pm
Early production, first couple hundred. Theres another difference; the rubber centerstand bumper is round and has smaller mount.
Title: Re: Exhaust Pipes
Post by: Steve Swan on February 17, 2010, 12:02:59 pm
Posted by Chris Rushton, Guest

My regular rider #1005298 still has an unstamped #1 pipe fitted which does have the indent just below the gearchange cover. Is this another variant!
Title: Re: Exhaust Pipes
Post by: 736cc on February 17, 2010, 12:03:33 pm
No, you got a "mid-later" unstamped HM300.  ::)
You sure you didn't hit it w/ a hammer to give it that dent?   ;)
Title: Re: Exhaust Pipes
Post by: kp on February 17, 2010, 12:04:23 pm
Fellas, my 69 CB750 VIN11970 has a set of original pipes and have HM300 stamped and nothing more and have no indent for brake or gear lever KP  :o
Title: Re: Exhaust Pipes
Post by: 736cc on February 17, 2010, 12:05:02 pm
Those poor Ozzies  :'( don't get wrinkles or indents w/ their early CB750's (but they get plenty of Fosters)  ;D
Title: Re: Exhaust Pipes
Post by: elisent on February 17, 2010, 12:05:47 pm
My original 70 around 31000. I forget the exact# has unstamped no indent original pipes.
Title: Re: Exhaust Pipes
Post by: benjixt on June 28, 2018, 12:54:05 pm
My original 70 around 31000. I forget the exact# has unstamped no indent original pipes.

So this cb750  (31000 range )is with
Unstamped exhaust...!!