Topic: New CB750 4-4 pipes: your thoughts and opinions?

[HondaMan]

Honda's vendor for the new CB750 pipes has made some mistakes. The toughest one to deal with is the misplaced spacer on the #2 pipe, which causes a mismatch at the rubber coupling nipples at the rear of the pipes. Some of us have ground down the inside of the little misplaced bushing, then spaced out the #1 pipe to (sort of) compensate, but it's not simple. Some of us have bent the #1 muffler (which if done too vigourously can become an expensive crumpled muffler) until it fits.

In addition, after just 18 months, mine have started to rust and pit on the head pipes. I don't know if anyone else has this, but the OEM ones lasted 40 years, so this should not be happening (especially for $1200 per set).

The finish on the crimped seams is not as well done as Honda used to have, either. Overall, I'm disappointed (at best) with Honda's current pipes. So, with sheet metal designers and shops looking for work, I'm considering pursuing the production of pipes.

These will probably be seamless, rolled mufflers in the same diameter, with the reverse cones for improved midrange torque, as the originals, and will look very similar (except for no seams). Personally, I've always thought the 2-halves-welded-together approach seemed cheesy, but I know that's just my taste. (Comments?)

I haven't determined whether I'd do just mufflers, requiring you to saw off your head pipes and use them, or whole pipes, which will be expensive (like in the poll options above). If they become slip-ons, there is always the issue of making a good seal, no small matter. But, the CB750 is set up in such a way that a slip-on version will be pretty well disguised, under the engine. Jardine took good advantage of this with their cheap 4-2 slip-on replacements for years, where most folks never realized they were just mufflers.

In any event, they WILL have superior chrome.

Please jump in with your comments? I'm not decided on the "plan" just yet, but am trying to assess the potential market. I may be able to get external help for this little project, and a marketer.

[zoo mob]

I'd throw a grand at a set of superior HM300 replacements.

[GammaFlat]

Will your pipes come with baffles?  ...or will factory baffles fit?  I'm baffled
Will the factory shields mount to the pipes? 
I imagine it wouldn't be too hard to find a set of wrecked pipes where the head pipe sections are still good.  That option sounds nice especially if it significantly impacted the cost. 

Thanks for continuing to do cool stuff with the ole CBs.   Whatever you end up with, I'm probably in for one set. 

[BobbyR]

Let's see how the numbers fall. I complete pipe would be more attractive to some since the head pipes can really look ratty after a while. You may want to consider the option of slip on and complete pipe. The original head pipes were well done, but the mufflers were crappy.

[Honda George]

I agree with you about the original mufflers. They were poorly done and did not last long. I would want something that looks fairly close to the stock pipes and mufflers but last far longer then the originals. I would want a set.

[petercb750]

Having purchased some new pipes (341s) about 3 years ago, I'm not yet in the market for replacements, but commend you for this idea. It may well be a worthwhile exercise if you can get the numbers.
Personally, I'd prefer to see the seams - they are original, and on the bike look "natural" and authentic. Seamless may be a clean look, but will always look "after market' and not original. OK for some people, not others seeking originality, but then that is probably not necessarily your intent.

And wouldn't pipes with seams be cheaper to make? I'm no expert, but would think welding 2 halves together is easier than rolling one round pipe?

I agree the new pipes currently on offer are not 100% - my chrome is ordinary to say the least, and I had trouble with the LH side rear mounting points. But when polished up they look great and hopefully will last a few more years.
Cheers.

(I read an article recently here in Oz of a guy who made his own CBX pipes - full set, identical down to the drain holes in the ends of the mufflers, all in stainless steel - absolutely awesome. Very clever. Hate to think how much it would cost as a customer!!)

[Bob750]

HondaMan, have you already seen a relevant thread by Popwood? http://forums.sohc4.net/index.php?topic=71881.0 I think these threads could be merged in a way that could serve all on the board. We all want nice 4-4 sets but the cost and quality of the "new" sets is bad...

Yes. I'd be interested in your after-market improved reproductions.  I just this afternoon pulled my original, rusted out 4-4 pipes out of my parents storage garage (I've been running a rusty black Mac 4-1 system for a while now. One of my mufflers has a 4x4 inch hold in the back side exposing one baffle. I'd need a talented and cheap repair person for me to use that set again.

Speaking of improved reproductions, has anyone had any experience with TAS Classic Motorsports' fork tubes http://store01.prostores.com/servlet/tasclassicmotorsports/the-680/CB750-Fork-Tubes/Detail ?

[bwaller]

From the beginning (1973) I got in the habit of removing the pipes a couple times a year to clean & polish. It only takes a couple hours. I have one set hanging in perfect shape except the chrome is worn thin and looks more gold than chrome!

Rechromers frown on the carbon so for now I'll just keep them.

Long story short H'Man I would be interested, I doubt you could duplicate Hondas header pipe quality though. I don't mind if they're seamless, but as you mention the reverse cone needs to stay.

[eddy]

They need to be original or the value would be very low, why not copy the original design?

[Popwood]

Sure would be important to know if others who put Honda's replacements in use over the past few years are finding the same issues as Hondaman. Let's hope we get some comments. Gives me real second thoughts about ordering those and depresses me even more to think the option presented here would be well over $1000.

For what it's worth, I don't need a 100% original look. Seamless not an issue for me.

And since I started the other thread referenced above, I'll keep watching this one with great interest.

[HondaMan]

Sure would be important to know if others who put Honda's replacements in use over the past few years are finding the same issues as Hondaman. Let's hope we get some comments. Gives me real second thoughts about ordering those and depresses me even more to think the option presented here would be well over $1000.

For what it's worth, I don't need a 100% original look. Seamless not an issue for me.

And since I started the other thread referenced above, I'll keep watching this one with great interest.

Thanks for jumping in, Popwood! I didn't realize you had a similar-like thread going. If you can organize something with Western Hills (or someone like that) for a batch of pipes at a reduced price, count me in! I'm always building 750s, and a set of new Honda pipes would go well on those, despite the fact that [currently, at least] their quality seems a little lower than a few years ago. I've noticed over the years that Honda has a way of going in and out of this problem: they are an honorable company and don't like cheesy product. It may be that they haven't yet heard of the issue, since it started just 2 years ago, and with the current market issues their attention might be pretty busy elsewhere. I'd talk with the local Honda dealer about it (RPM) and have them communicate it to Honda, but they don't give a rip unless you're buying a new bike.

I bought some replacement pipes 3 years ago (for the bike on the cover of my book) and they were properly made (not needing to be modified just to fit) and the chrome was Honda's usual good quality: the ones I bought 7 months later for my own bike are the ones I've been referring to, as have others here who are struggling with the fit of the #2 pipe. It appears to be a situation similar to the CB350F "broken mold" scenario, where just the #2 pipes is now different, that causes the problem. I first discovered that this is the root of the problem when I replaced just the #2 pipe on my own bike first: it caused the fit-up problem with both it and the #1 pipe. It was then I ordered the other 3, only to find out they had not modified the whole set, just mismade the #2.

If we can't organize a "group buy" for say, 10 or 12 full sets of pipes as a "club", then I would certainly run full speed ahead into either stainless steel pipes or at least chromed mufflers. BTW all: if I do this, it will be with removable baffles so there can be 2 types. 
The sound of those glasspacks is sweet, but on long tours while 'on cam' behind a fairing, they can get to be a nuisance. That's why I was willing to switch to the K2, years ago.

Let me know what Western Hills says, if you talk with [Terry]? They have been supportive of all of us, and it would be great to support them back in this situation. If they were to get 10 or 12 sets and be willing to let them out at, say, 10% margin (or whatever they'd negotiate with us) in say, August, which is typically the dying part of the biking year, we could all win. 

[Duke McDukiedook]

If you can get better quality than what is being put out at $1200 a set, I will be game (at less than $1200).
Let us know what the minimum numbers we would need to get a fixed price point for better quality.

I think Benjie's pipes run about $1200 for stainless 4-4 and his are pretty good quality from what I hear. We should be able to get it below $1200 in numbers, below $1000 would be even better.

[phactory]

I have bought two complete HM300 exhaust systems in the past 2 years and have had not had the fitment problems you describe. I actually pre-fit both sets to my K1 just to make sure thet there wasn't going to be ANY fitment issues.

I did have an issue with the heat shield not fitting properly on one of the mufflers in the second set I bought, but my dealer worked with me to resolve the issue to my satisfaction. Personally I would only be interested if they were exact copies.

One set is for my K1 and the other is for my Rickman.

Phil

[HondaMan]

I have bought two complete HM300 exhaust systems in the past 2 years and have had not had the fitment problems you describe. I actually pre-fit both sets to my K1 just to make sure thet there wasn't going to be ANY fitment issues.

I did have an issue with the heat shield not fitting properly on one of the mufflers in the second set I bought, but my dealer worked with me to resolve the issue to my satisfaction. Personally I would only be interested if they were exact copies.

One set is for my K1 and the other is for my Rickman.

Phil

That's good to know, Phil: the ones I've been buying are all HM341s.

[phactory]

That's good to know, Phil: the ones I've been buying are all HM341s.

HondaMan,

 Actually I couldn't believe how well they fit as I had always heard horror stories about fitting them! Once I realized the the #2 and #3 pipes go inboard of the frame, I had the set on literally in less than 5 minutes! I love stock exhaust!!!   I am installing a set of MAC 4 into 2 on a K3 right now and am just amazed at the way they fit... sic  

 HM, why not get the HM300's instead? They are vastly superior and could only help!

Phil

[754]

Peter , you can roll cones on an 800.00 machine.

 To make a split exhaust in the way Honda did, 50 K might get someone STARTED on the dies...  would be a down payment..

 Sito altready make some replacement Honda 4 exhausts, in maybe stainless.. and they are priced accordingly.

 Everyone has to be realistic in the cost of making this stuff. I think Hondaman is.. the other thread, let me say this.. you cant expect someone to work for less pay, just so you can play cheaper..

[BobbyR]

It would appear that we have two market segments. One group desires restoration correctness and one desires "correctness" mixed with longevity. Each group has valid reasons. I have a 78K and the only seam is at the bottom with what appears to be resistance welds.

I personally would opt for a SS version that looked close enough. I bought my bike with 12K miles in it and the pipes were shot. I bought very clean another set from a member of the old Greenspun board. Over the past couple of years the welders at work had patched everything that could be patched. I bought an OK set from ebay. If I had a SS set I would be happy to trade exactness for longevity.

[swellguy]

Benji just built me a set of 4 into 4 pipes for my 73 cb750 cafe project:

[co425]

Benji just built me a set of 4 into 4 pipes for my 73 cb750 cafe project:

Yep my next build is going to be stainless probably with those pipes. Then ceramic coated Black.

[swellguy]

Yep my next build is going to be stainless probably with those pipes. Then ceramic coated Black.

You don't need to to go to the expense of stainless if you want to ceramic coat them black.

[Bob750]

Benji just built me a set of 4 into 4 pipes for my 73 cb750 cafe project:

What's the going rate on those stainless ones, if I may ask?

[swellguy]

What's the going rate on those stainless ones, if I may ask?

$1,200 plus shipping. 50% deposit due, approximate wait time 6-8 weeks (in my case).
Say goodbye to your center stand though:

[Bob750]

What's the going rate on those stainless ones, if I may ask?

$1,200 plus shipping. 50% deposit due, approximate wait time 6-8 weeks (in my case).
Say goodbye to your center stand though:

Damn, those are gorgeous. I could just lick 'em... And hey, no corrosion! ;-)

[lone*X]

Yep my next build is going to be stainless probably with those pipes. Then ceramic coated Black.

You don't need to to go to the expense of stainless if you want to ceramic coat them black.

Appearance wise you are correct, but my experience is that the stock pipes always rusted out from the inside.  Polished  stainless may not be Concours correct but it will last a lifetime. 

[HondaMan]

Those Benji pipes look to be pretty good muffler segments: maybe a start? 
I can't live without the centerstand, though, and don't intend to make that happen if we go forward on this little project.

Honda's pipes are about $1050 to $1200, depending on where they are found, and the Benji pipes will certainly outlast them. That makes the Benji units worth those $$ figures, outside of the stand issue! I'm sure they went underneath like that so as to avoid having to dimple the pipes to clear the things Honda has, without going too low under the frame. All of the 1970s era 4-1 pipes did the same thing: Action Fours' pipe even blocked off the oil filter and crankcase oil drain bolt, requiring pipe removal at every filter change, plus the loss of the centerstand. Duh.

Don't want to do those things...