Topic: Stock 4-4 exhaust. No new no no's now.

[Don R]

 Yup Customs did not contact me. One box was marked as out for delivery, on the truck and went all the way back to Italy. A different set was reportedly in New Zealand and was recalled.

[JamesH]

I'm 'itching' for you to fit these now Don. I'm genuinely hoping they fit well and as you step through it you may discover some fitting technique/approach that I missed out. On all 5 of my sets I've had to modify (cut down by 10mm) the pipe and outer sheath where it goes into the exhaust spigot.

[Don R]

 The innie head pipe looks long to me. Just judging by appearance. I'm trying to get the lift cleared but one POS that my brother bought, sold to me and bought back and somehow became my issue refuses to run right.

[Tracksnblades1]

Wow, great news..😁

Patience prevailed…😇

Looks like Italy’s government bureaucracies practices mirrors ours…
Keeping everyone in the dark and ruining there own business’s reputation…😡

Glad it worked out for you after a couple of years…?..?

[Don R]

   Trust me, I was less than patient. There are a few in the group still waiting for their pipes. When they get theirs, I'll post an installation report with pictures.

[grcamna2]

   Trust me, I was less than patient. There are a few in the group still waiting for their pipes. When they get theirs, I'll post an installation report with pictures.

Yeah Don,I look forward to that.
I also hope you give some Long Overdue messages/feedback about BUSSO or BSAI: Bull Sh*t Artists of Italy. 

[PeWe]

These were the same ones previously held at Customs, the old tracking numbers are on the boxes. I had stopped tracking them when these numbers quit working. I'm looking forward to hearing that everyone who paid for a set is getting their packages now.

So the story about shipped but customs issues was true then.
Strange that customs did not contact you.

Highly doubt Customs would go through the trouble to try to contact the recipient, it didnt pass for whatever reason, so it was sent back.

They do here.
I have got packages where they ask me about the content and value so the can charge me before shipping to me.
Last time a cam from Mike.

One time a pipe from Yamiya, free replacement. I got one no number pipe in the package of Lotus Root pipes.
I had to inform them about the initial customs numbers and my return shipment of the returned pipe to not charge me customs.

[Don R]

  I guess I've been lucky ordering from various countries with no tariff issues. I did sell two rims to a guy in Canada decades ago and UPS contacted me for more money after I had gotten two quotes to ship them. I told them to go pound sand.

[carnivorous chicken]

These were the same ones previously held at Customs, the old tracking numbers are on the boxes. I had stopped tracking them when these numbers quit working. I'm looking forward to hearing that everyone who paid for a set is getting their packages now.

So the story about shipped but customs issues was true then.
Strange that customs did not contact you.

Highly doubt Customs would go through the trouble to try to contact the recipient, it didnt pass for whatever reason, so it was sent back.

They do here.
I have got packages where they ask me about the content and value so the can charge me before shipping to me.
Last time a cam from Mike.

One time a pipe from Yamiya, free replacement. I got one no number pipe in the package of Lotus Root pipes.
I had to inform them about the initial customs numbers and my return shipment of the returned pipe to not charge me customs.

I ordered 350F silencers from Busso and they sent headers, but I had to pay customs on the higher priced silencers. When they sent out the silencers, I had to pay the (higher) customs fees again. I guess I about broke even but it took a very long time and I #$%*ed about dozens of pages ago on this thread).

[69cb750]

[Don R]

 That's a significant difference. The next time one of mine comes out of the box I'll get a close-up of the ends. My Yamiyas are installed as are the CMSNL pipes.

[jwurbel]

I have a #2 bought in a set from Yamiya.  It needs to be cut by 10mm or so.  How do those of you that have done it do it?  My attempts in using a hack saw on other projects always results in crooked results.  Any information would be appreciated.

[JamesH]

I have a #2 bought in a set from Yamiya.  It needs to be cut by 10mm or so.  How do those of you that have done it do it?  My attempts in using a hack saw on other projects always results in crooked results.  Any information would be appreciated.

I had to ‘modify’ the ends of my Yamiya pipes by approx 10 mm across the board.

I used a cordless makita angle grinder with a thin cutting disc (similar to pictured, I used a genuine Makita disc)

[Don R]

 In light of Yamiya's needing to be trimmed I can't help but wonder if someone in Italy used a Yamiya for their patterns?

[PeWe]

So Yamiya can differ too?
Compared with Honda stock pipes?

My set of Yamiya No numbers used on 2 bikes. First on my K6, now K2-1975 with K2 frame number.

Then Yamiya Lotus Root my K6 has used.
I noticed a smaller difference between bikes how far in the pipes had to sit on ex spigots.

[JamesH]

In light of Yamiya's needing to be trimmed I can't help but wonder if someone in Italy used a Yamiya for their patterns?

I’ve fitted 10+ sets of Yamiya pipes and never once had to modify them to fit. I’ve had one #2 pipe that took some gentle ‘persuasion’ to get to line up, but nothing like the ordeal of modifying every Busso pipe. They are leagues apart in dimensional accuracy.

[Oddjob]

Howdy James.

Glad to see there may be a resolution to the Busso problem.

[JamesH]

Howdy James.

Glad to see there may be a resolution to the Busso problem.

Seems to be light at the end of a very long tunnel - I still have a fitment issue with every #3 pipe in my 5 sets. They’ve assured me they will replace the pipes FOC when they have stock (whenever that will be?). Apparently they updated the tooling for pipe no 3 in this latest batch (hopefully DonR’s pipes have this design modification as well).

[Terry in Australia]

Spotty and I had a great day in his garage today. Somehow Spring has reverted to winter this weekend, with the temps in the low 50's, and pissing down rain that was getting blown into his garage's main door, just where we like to stop and have a cigarette during a hard day's tinkering. Anyway, we finally opened my new Yamiya exhaust system for my K0, after it's sat in my garage for most of this year. It was a bit like a scene from "Raiders of the lost Ark" as we both caught our breath when we saw how well it was packed, and how shiny the pipes were!

K0 Saturday 14 September 2024 by Terry Prendergast, on Flickr

Installation was straight forward, but would probably have been easier if I had the correct bolts for the footpegs. The bolts are 14mm OD, and the OEM bolts are "Necked down" to 12mm threaded section that protrudes through the mount on each side of the frame, but all I had were 14mm bolts. As an experiment I'd actually used my super dooper magnetic heating coil to soften the threaded portion on one of the 5 bolts I bought from an Ebay seller, then used my lathe to cut the old thread off the bolt, then used a 12mm threading die to cut a new thread a few months ago and it worked fine, but when I tried it on another, either I hadn't heated it enough, or the die was fcuked, because the second one didn't work as well and was a biach to thread, so I gave up and just used two 14mm bolts, after Don told me the overall length of the OEM bolts.(thanks mate!)   

I was absolutely stoked, after some of the guys here told me that the insides of their Yamiya pipes weren't coated, but mine were, so hopefully they won't rot out like the originals did. On top of that, I happily discovered that the box contained new K0 style heat shields, and all the fitting hardware that apparently usually aren't included, even the joiners and clamps at the rear of the mufflers. The only things it didn't have were the two rubber bump stops for the stands, but Spotty ratted through a box of various rubbers, and we found two that will do the job, so fitted them.

K0 Saturday 14 September 2024 1 by Terry Prendergast, on Flickr

We'd installed the ignition (Dyna S ripoff from China) and I'd thought that the white wire connected to the yellow wire, and the black wire connected to the blue wire, so had reconnected them a couple of weeks ago. When we went to start it, it was sparking with a beautiful fat blue spark (with my little jumper attached to the battery) but wouldn't start, so I swapped the above mentioned wires around, and it fired right up, at around 5000 RPM! Fcuk!

I'm guessing that one of the slides is hanging up. Spotty and I had (we thought) routed the 1 into 4 throttle cables really well, so wondered if the tank was pushing down on the cables, so we released the rear of the tank and propped it up above the cables, but it made no difference, so next time we work on it we'll check the cable from the handlebars to the carbs, and if we can't find anything, we'll remove the airbox and see if I've somehow installed one of the slides backwards.

Regardless, it was running on all four cylinders, and has more compression than any CB750 I've owned, even those with high comp big bore kits, and I had to go find my jump pack so I could crank the engine over. Good thing was that there are no apparent oil leaks, and the pipes look lovely. I'm really looking forwards to a nice warm day so I can clock up some miles on the old beast.

K0 Saturday 14 September 2024 2 by Terry Prendergast, on Flickr

K0 Saturday 14 September 20243 by Terry Prendergast, on Flickr

K0 Saturday 14 September 2024 4 by Terry Prendergast, on Flickr

K0 Saturday 14 September 2024 5 by Terry Prendergast, on Flickr   

[PeWe]

Good news, Terry!
4-4 makes the CB750 look very fine.

Do you have the soft "wool" around the diffusers/baffles?
I took it off on mine for better flow. A little bit louder

[JamesH]

Spotty and I had a great day in his garage today. Somehow Spring has reverted to winter this weekend, with the temps in the low 50's, and pissing down rain that was getting blown into his garage's main door, just where we like to stop and have a cigarette during a hard day's tinkering. Anyway, we finally opened my new Yamiya exhaust system for my K0, after it's sat in my garage for most of this year. It was a bit like a scene from "Raiders of the lost Ark" as we both caught our breath when we saw how well it was packed, and how shiny the pipes were!

K0 Saturday 14 September 2024 by Terry Prendergast, on Flickr

Installation was straight forward, but would probably have been easier if I had the correct bolts for the footpegs. The bolts are 14mm OD, and the OEM bolts are "Necked down" to 12mm threaded section that protrudes through the mount on each side of the frame, but all I had were 14mm bolts. As an experiment I'd actually used my super dooper magnetic heating coil to soften the threaded portion on one of the 5 bolts I bought from an Ebay seller, then used my lathe to cut the old thread off the bolt, then used a 12mm threading die to cut a new thread a few months ago and it worked fine, but when I tried it on another, either I hadn't heated it enough, or the die was fcuked, because the second one didn't work as well and was a biach to thread, so I gave up and just used two 14mm bolts, after Don told me the overall length of the OEM bolts.(thanks mate!)   

I was absolutely stoked, after some of the guys here told me that the insides of their Yamiya pipes weren't coated, but mine were, so hopefully they won't rot out like the originals did. On top of that, I happily discovered that the box contained new K0 style heat shields, and all the fitting hardware that apparently usually aren't included, even the joiners and clamps at the rear of the mufflers. The only things it didn't have were the two rubber bump stops for the stands, but Spotty ratted through a box of various rubbers, and we found two that will do the job, so fitted them.

K0 Saturday 14 September 2024 1 by Terry Prendergast, on Flickr

We'd installed the ignition (Dyna S ripoff from China) and I'd thought that the white wire connected to the yellow wire, and the black wire connected to the blue wire, so had reconnected them a couple of weeks ago. When we went to start it, it was sparking with a beautiful fat blue spark (with my little jumper attached to the battery) but wouldn't start, so I swapped the above mentioned wires around, and it fired right up, at around 5000 RPM! Fcuk!

I'm guessing that one of the slides is hanging up. Spotty and I had (we thought) routed the 1 into 4 throttle cables really well, so wondered if the tank was pushing down on the cables, so we released the rear of the tank and propped it up above the cables, but it made no difference, so next time we work on it we'll check the cable from the handlebars to the carbs, and if we can't find anything, we'll remove the airbox and see if I've somehow installed one of the slides backwards.

Regardless, it was running on all four cylinders, and has more compression than any CB750 I've owned, even those with high comp big bore kits, and I had to go find my jump pack so I could crank the engine over. Good thing was that there are no apparent oil leaks, and the pipes look lovely. I'm really looking forwards to a nice warm day so I can clock up some miles on the old beast.

K0 Saturday 14 September 2024 2 by Terry Prendergast, on Flickr

K0 Saturday 14 September 20243 by Terry Prendergast, on Flickr

K0 Saturday 14 September 2024 4 by Terry Prendergast, on Flickr

K0 Saturday 14 September 2024 5 by Terry Prendergast, on Flickr   

Great work Terry - you must be pleased with that. What a ripper!

[MauiK3]

Nothing like stock exhaust, they look beautiful.
And I didn't have any trimming to do either.

[Tracksnblades1]

69,

Are the OD of the two pipes the same..? The inner pipe with shorter outer chrome clamp area on the right looks considerably larger than the left..or is my IPad and mt cataract implants playing tricks on me..?

[69cb750]

Are the OD of the two pipes the same..? The inner pipe with shorter outer chrome clamp area on the right looks considerably larger than the left..or is my IPad and mt cataract implants playing tricks on me..?

Busso inner pipe od=1.350"
Honda inner pipe od=1.379"
Outer pipe od=1.672" (Original and Busso)

[Tracksnblades1]

Are the OD of the two pipes the same..? The inner pipe with shorter outer chrome clamp area on the right looks considerably larger than the left..or is my IPad and mt cataract implants playing tricks on me..?

Busso inner pipe od=1.350"
Honda inner pipe od=1.379"
Outer pipe od=1.672" (Original and Busso)

That machine must’ve picked the correct Multi-focal implants 😇
It looks bigger than 0.029, must just be the photo …
Carry on..👍

Largest tubes I’ve ever measured were original Yoshimura and RC engineering 4/1s, 1.498- 1.502 depending on chrome or painted…and probably how many times…🤪