Now Available!! Exclusive at Webike! Yoshimura’s Full Exhaust for WR155R

Since the production of the Cerro 250 was discontinued in 2020, Yamaha's public road off-road motorcycles for the Japanese market have been absent from the lineup. While the YZF-R15 has been announced for introduction in Japan, the WR155R, an off-roader with the same engine, is also expected to be introduced in Japan.

The WR155R is a full-size, full-fledged off-roader with 21-inch front wheels, and is a popular model that is used like a Serow, taking advantage of its lightweight body.

There was no way that Yoshimura could miss the one and only WR155R, and they had been developing an exhaust system for some time. The exhaust system has finally been completed! The exhaust system is not a slip-on, but a full exhaust.

Moreover, this Yoshimura-made full exhaust is a limited release at Webike!

This product is not sold anywhere else, so please don't hesitate to purchase it.

Valuable government-certified exhaust

The WR155R had few exhaust systems that were compatible with the WR155R, partly because it was a model that had not been introduced in Japan. Even if they were compatible, they were all for racing use, and none of them could be used on public roads.

The first such exhaust system for the WR155R that can be used on public roads is probably the Yoshimura  GP-MAGNUM CYCLONE EXPORT SPEC Government-Certified exhaust system machine.

Although the 155cc class is not subject to vehicle inspections, it is of course illegal to install an exhaust system that is louder than the regulation value or to remove the catalyzer (catalytic converter) for exhaust gas purification. However, Yoshimura's exhaust system complies with both emission and noise regulations and is certified by the government. It is completely legal and can be used on public roads with peace of mind.

The proximity exhaust noise level is 92 dB (decibel), so it is not disturbing to neighbors. However, the silencer used is a GP-MAGNUM Cyclone with straight exhaust, so the sound changes to a 4-stroke engine-like bass sound that cannot be compared to a normal silencer.
It produces a throbbing sound from idling, and the higher the rpm is raised, the more sporty and bouncy the sound becomes.

Video for sound quality reference： Exhaust sound of GP-MAGNUM Cyclone for Monkey 125 is at the bottom of the page.

WR155R with a silencer with a left exit
Yoshimura also has a left exit, but the image is completely different

What is GP-MAGNUM?

The Yoshimura GP-MAGNUM is a silencer with a traditional and simple round shape.
A closer inspection reveals that the silencer is equipped with Yoshimura's original dimpled rivets (rivet flange has a hemispherical indentation to improve the design and to show Yoshimura's spirit to reduce weight, even if only slightly), a rivet band without a rivet (a band to protect the rivet from getting stuck in the silencer's outer tube), and a rivet band without a rivet with a long hole in the part without a rivet. The band protects the rivets from getting stuck in the silencer outer sleeve, and the part without rivets has a long hole cut out to achieve both design and weight reduction. The parts are assembled using Yoshimura's typical parts.

The beauty of the neatly aligned weld bead is also a usual Yoshimura product itself.

The GP-MAGNUM logo is laser-marked on the rear end of the silencer, giving it a very racy look.
In addition, a thin ring is welded to the exhaust system end to double the wall thickness, which has the effect of preventing the exhaust system end from sticking into the rider's body when it faces the rider in a fall. There are many silencers out there with similar shapes, but the quality is completely different.

Of course, its performance is second to none. It delivers abundant torque from the moment the accelerator pedal is opened, with excellent response and an exhilarating driving feel all the way up to the high rpm range.

As with other Yoshimura products, silencer covers and glass wool can be remade. If the silencer cover is scratched due to a fall or if the volume level rises with age, Yoshimura's technology can remake the silencer cover so that it can be used for many years to come.

The black and gold color scheme gives the emblem a chic appearance
GP-MAGNUM logo is engraved on the silencer end.

The image shows the GP-MAGNUM silencer for the Monkey as seen from the exhaust port.
There is no partition to block the exhaust to the other side because it is a straight exhaust.

You can see the silencer end section where the pipe has not been cut off because a thin ring is fastened to the rear end.

Three types of silencer coloring

The machine tune GP-MAGNUM CYCLONE EXPORT SPEC Government-Certification, sold exclusively by Webic, is available in the same silencer coloring as other Yoshimura products to suit your preference.

Three types of coloring are available.
SS (stainless steel cover) with a polished finish, tax included, (approx.) 489 USD
SSF (Satin-finish cover), which has a calm, pear-like finish, has a list price of approx. 511 USD (tax included)
STB (titanium blue cover), popular for its beautiful burnt color, price approx. 586 USD (incl. tax)

The titanium blue cover weighs 3.2 kg, while the others weigh 3.5 kg, which is less than 65% of the OEM exhaust system, which weighs 5.4 kg.

SS (Stainless steel cover)

SSF (Satin Finish Cover)

STB (Titanium blue cover)

What is EXPORT SPEC?

Needless to say, Yoshimura products are very popular among overseas users.
In addition to the fact that the brand itself is legendary, its performance and durability are known to be incomparable to other brands.

However, overseas users who are particular about their products have nothing to do with the Japanese fashion trend, and they tend to prefer the burnt color of artisanal welding (Tig welding) and the presence of machining marks, while placing importance on performance.
Many enthusiasts want to directly feel the excellence of Yoshimura's welding technology by seeing the welding process marks on the highly durable stainless steel used as the material.

The EXPORT SPEC is finished with the original processing marks to meet the tastes of these overseas users. In addition to the fact that a part of the production is done at Yoshimura's Asia factory in Thailand, it is also characterized by its excellent cost performance while realizing Yoshimura's unique and sophisticated design and style.

No polishing process is applied afterward to remove weld burns and bead marks. The best part of the EXPORT SPEC is that you can see Yoshimura's welding technology as it is.

Exhaust shape

Compared to the OEM exhaust pipe of the WR155R, the Yoshimura pipe is clearly thicker and consists of gently curved large curves. In particular, the shape just after the exhaust port is completely different. While the OEM exhaust pipe is pointing downwards, Yoshimura's exhaust pipe is curving naturally almost to the side. The exhaust pipe has a multi-stage tapered shape that becomes thicker as it gets closer to the silencer, which is a glimpse of a design that is actively trying to draw exhaust air out of the exhaust.

However, Yoshimura does not sacrifice low speed in exchange for high RPM and high output.
Yoshimura's original development tests have resulted in output characteristics that exceed those of the factory unit throughout the entire range.

Although the large increase in top-end output tends to attract attention, it should also be noted that the torque around 4000 rpm, which is frequently used for city driving and off-road driving, has also been improved.

Multi-stage tapered exhaust pipe section that gradually thickens toward the silencer

The power curve changes like this The upper graph shows horsepower and the lower graph shows torque.
What is noteworthy is the fact that both a large increase in power output at the top end and an increase in torque below 5000 rpm are achieved.
Very Yoshimura-like!

Here is the OEM exhaust pipe shape
Thin, curved, heavy, and black.
Compared to the Yoshimura, it should be easier to hit rocks in a gully

Bolt-on installation

Yoshimura products are of such high quality that they exceed the quality of OEM  parts, so installation is completely bolt-on. There is no need to cut a part of the vehicle body or have any part of the product come in contact with any part of the vehicle body, which is a common problem when installing a full exhaust system. The OEM exhaust gasket can also be used.

No modifications of any kind are required to the body or exterior of the vehicle. The quality of the product itself is perfect, as is typical of Yoshimura products, and all parts align perfectly. There are no problems with the stay screw holes not fitting properly, which is common when installing a full exhaust system.

Product Specifications

SS (Stainless steel cover)

Stainless steel polished finish

SSF (Satin Finish Cover)

Stainless steel with pear finish

STB (Titanium blue cover)

Titanium with browning