Topic: NOS 4-4 pipes! Yikes

[seaweb11]

http://cgi.ebay.com/ebaymotors/Honda-CB750-Exhaust-OEM-HM300-All-4-Pipes-CB-750_W0QQcmdZViewItemQQcategoryZ35596QQitemZ4627946102QQrdZ1

[74cb750]

Well, what did you expect?
OEM from Honda costs around $1600 complete. This set does not seem to have the
shields.
peace,
michel

[GroovieGhoulie]

Brand-new HM300 pipes are available from DSS for 119 pounds each, which is $207.34 as of today.  Times four means that a complete set of new HM300 exhausts are $829.36 plus shipping, which I imagine would be insane.  However, I'll bet you would get away for around a grand, which is far less than $1600.

[6pkrunner]

I can get a complete set, with shields for $1489 CDN right now. At at todays exchange thats $1296.46 USD. But one would have to add taxes and such to get the true total cost.
Still too much. There are sill quite a few almost perfect used sets going for $400-$600USD.

[techy5025]

I contacted the seller of these pipes.  They are the same ones David Silver is selling and
are the "paragraph" pipes that have the epa stuff engraved in them. You can get them
much cheaper, including shipping from David Silver.....HM341's are even cheaper.

I don't trust the used ones sold on ebay as there is no real way to inspect the insides
for rust.  You may be close to a rust through.  At least with new ones you know where
you stand....of course I guess that's true of all new parts.

Now if someone is selling HM300's with "no numbers" the price will probably be over a
thousand even with holes.  K0 and sandcast you know. 

Jim

[GroovieGhoulie]

Please describe these "paragraph pipes".  Do they have more than the "HM300, Honda Logo and Model number stampings?

[techy5025]

Yes, they have a whole "paragraph" of text that is engraved in the pipes. I have the full text
somewhere but it basically says they can only be used on a bike made prior to (I think) 1977 as
they do not meet current epa standards.  This is why they call them paragraph pipes.  I don't
know where they engrave it but hopefully it isn't on top at the back. 

I've been looking for a picture of a pipe with the text but can't seem to find one.  This well
be my forth set of pipes....three for the K0 and now one for the sandcast.  I prefer the 341's
which I know are not correct, but for some reason seem to last longer and at nearly a thou a
set is my main goal. 

Jim

[GroovieGhoulie]

Yes, they have a whole "paragraph" of text that is engraved in the pipes. I have the full text
somewhere but it basically says they can only be used on a bike made prior to (I think) 1977 as
they do not meet current epa standards.  This is why they call them paragraph pipes.  I don't
know where they engrave it but hopefully it isn't on top at the back. 

I've been looking for a picture of a pipe with the text but can't seem to find one.  This well
be my forth set of pipes....three for the K0 and now one for the sandcast.  I prefer the 341's
which I know are not correct, but for some reason seem to last longer and at nearly a thou a
set is my main goal. 

Jim

I hear the reason the 341s last longer is the glass packing in the 300s traps moisture and lets it rot the metal in short order.  Dunno about how true that is.  For me, the "authenticity", volume and increased performance is worth getting the 300s.

[techy5025]

BTW...those pipes went to $1001 dollars and didn't meet the reserve. The UK price is
about 100 bucks less. 

Jim

[6pkrunner]

I don't trust the used ones sold on ebay as there is no real way to inspect the insides
for rust.  You may be close to a rust through. 

I do hear what you are saying, and I have been "awakened" twice so far. But I also have scored some real nice pipes. There are
a lot of guys breaking low mileage bikes as they know they can get more as parts than as a bike. I have a set of 341s coming from a 6300 mile California bike. The guy seemed honest and strightforward. I'll let you know how it works out.
But with 15 CBs to restore as of now, at over $1000 per set -a bit much for me.

[Raul CB750K1]

FWIW, I will buy a new set of CB350 pipes when the moment comes. Before even fitting them on the bike, I plan to paint the inside with Alu Zinc, a cold-galvanizing paint -the one that didn't work for the engine as the gas dissolved it- so I can forget about rust in them. It works even when the surface is already rusted, so I will probably use it on my HM300 too.


Raul

[techy5025]

I can't imagine what it woujld cost, but a set made out of stainless would
be great.....maybe just the muffler part as the headers seem to last forever.
For the price of three sets of pipes, I could have probably paid for a stainless
set.

I don't know if mileage is a good indicator as the bike I'm replacing them on
now only had around 8K miles.  I don't know if they are original but I suspect
they were as they are the no-number HM300's...more holes then swiss cheese
though.

That is an interesting theory about the packing holding the moisture in. Maybe
we should keep a tank of dry nitrogen in the garage and purge them after each
ride. 

15 CB's ...  I am truly impressed. I thought restoring two was a lot. 

Jim

[Ted Nomura]

I have 12 CBs, 5 CLs and 4 SLs, but no "sandcast" CB750 yet, just plain 1969 CB750 and two 1970 CB750s. Most are restored. Fortunately mufflers don't rust that much in Las Vegas. Too bad pipes are so expensive now but at least they're available. I still need stock muffler for my 1972 CB350, I got the bike free but mufflers are rusted through a bit. My first!

[GroovieGhoulie]

I still need stock muffler for my 1972 CB350, I got the bike free but mufflers are rusted through a bit. My first!

Four or twin?  350/Four exhausts are rare as hen's teeth because supposedly the mold used to stamp one of the pipes broke in the early '80s and no one replaced it, so a complete new set is impossible to attain.  The 350/Four exhaust supposedly rusted the worst because the engine was slow to put out enough heat to clear the condensation from the pipes and short rides would not let them heat up enough.

If your downpipes are ok, then you can get new silencers from an italian company:

http://www.mivv.it/moto_usa/prodotti_ricambi_case_apri.asp?codice_marche_moto=15

I think the 350 twin pipes are still available.