Yoshimura Honda CB400F Racing Straight Cyclone 4-Into-1 Exhaust
Yoshimura, the originator of the 4into1 exhaust! They’ve reissued the CB400F 4into1 exhaust and a few other performance parts for the CB400F and CB750. We’ll feature those as well and I’m hoping to get some of these parts in the store soon. Read below for more info from Yoshimura. . . .
You can even hear a sound sample here!
In 1971, the 4-into-1 exhaust system was developed by Pop Yoshimura first in the world for CB750F. Everyone was fascinated by the idea, the performance and the sound of the exhaust system. Still there was no 4-into-1 exhaust system from original bike in early 70’s, but CB400Four was introduced with it in 1974.
The time has flown already 38 years since then. Yoshimura Japan is proud of the fact that we have been keeping manufacturing the 4-into-1 exhaust system of CB400F while changing the shape & manufacturing process.
However the demands for the exhaust design from these days have never stopped and we decided to newly develop the exhaust system. It is not a replica of 70’s Yoshimura exhaust, but it is a modern genuine Yoshimura system for the CB400F enthusiasts.
A proficient craftsman bends artistic headers by burning pipes with burner one by one.
Traditional and accomplished production procedure.
The pipe intervals are wide enough for oil-filter change as same as the product at 70’s.
Pipe layout is applicable for both 408cc and 398cc engines.
Traditional style Yoshimura emblem is applied.
Yoshimura name (under emblem) is incised.
A bracket is newly added at the back of muffler for the durability.
4-into-1 design in a traditional style.
Artistic pipe work by hand bend procedures.
Steel 4-into-1 pipes make peculiar nostalgic sound.
Same 64mm-diameter steel pipe as at that era is special made only for this system.
Two types of different dB-killers are being supplied together with this exhaust pipe.
Type-R: Characteristic racy sound (Supplied by bolted on the exhaust)
Type-S: Traditional Yoshimura sound (Supplied as an optional part)
Granular surfaced cast flange gives a special flavor which matches the hand bent exhaust system.
Machined steel connecting pipes are applied.
Originally it was introduced with 408cc engine, but soon 398cc version was added due to new license regulation in Japan. It was unforgettable moment, and Pop and I was impressed to see the bike very first time, because there was a 4-into-1 exhaust system installed originally. We recognized such a big factory admitted our idea and the development. However, we had another idea on the pipe layout, then the “Traditional Yoshimura 4-into-1” exhaust system was developed. At that time Pop and I was already moved into USA, and we could not make the project successful without the help of our families in Japan (Moriwaki and Parts Shop Kato).
A scene of the history with CB400F
There was a test ride report introduced on a magazine article of April 1976.
Fujio Yoshimura brought a Yoshimura tuned CB400F into the test course and made the following record.
- Top speed: 180.00km/h
- 0-400m (A quarter mile) times: 12.8 seconds
Unfortunately the test was done with a slip-on due to Japanese noise regulation, and we should have made much better results if we could test with the 4-into-1 exhaust system.