Yamaha is reportedly looking into concerns from owners of early-build 2021 GP1800R SVHO WaveRunners equipped with the previous year’s 155mm transom plate – after 2021 models manufactured later in the production cycle switched to a 160mm design.
Numerous owners of the 2021 Yamaha GP1800R SVHO have revealed on social media platforms such as GreenHulk Performance’s Facebook page that their watercraft has a 155mm transom plate feeding into the 160mm high-performance jet pump, the same set-up as last year’s model.
However, other owners of 2021 Yamaha GP1800R SVHOs say their models came with a 160mm transom plate.
A transom plate is a thick metal assembly that routes water from the top of the intake grate and into the jet pump. The wider diameter design is said to improve the flow of water into the jet pump and reduce cavitation on take-off.
For years, the GP1800R SVHO has had a smaller 155mm ring in the transom plate feeding water into a 160mm jet pump.
However, it is now apparent there has been a change to a larger diameter 160mm transom plate on the most recent examples of the 2021 Yamaha GP1800R SVHO.
In online forums, owners have identified the part number change: the 2020 model’s 155mm transom plate part number is 6CS, whereas the 160mm transom plate part number is 6JN.
Concerned owners of early-build examples of the 2021 Yamaha GP1800R with a 155mm transom plate believe they are entitled to a free replacement with the 160mm version.
For now, Yamaha representatives in the US, Japan or Australia are yet to comment on whether the parts will be replaced. Dealers are also yet to be informed of any developments.
At the centre of the issue is a claim Yamaha did not highlight the new 160mm transom plate in its promotional material or information to dealers in the lead-up to or following the launch of the 2021 Yamaha GP1800R SVHO.
The official launch video for the 2021 Yamaha GP1800R SVHO – narrated by Yamaha WaveRunner’s global product manager, Scott Watkins – makes no specific mention of a change to the transom plate.
The video highlights the 2021 model’s new top deck, adjustable handlebars, digital dash, and larger storage areas – and the introduction of launch control and cornering control technology.
The promotional video (shown at the bottom of this story) also covers changes to the hull’s inner lining and the repositioned fuel tank, which has been mounted 50mm lower and 80mm rearwards for better balance.
The closest the Yamaha promotional video gets to the transom plate area is when Scott Watkins explains the 2021 model has a “redesigned intake grate and upgraded jet pump that allows less turbulent water to flow through the jet pump”.
“The result is better acceleration and less cavitation in choppy waters,” says Watkins.
There is no specific mention of a 160mm transom plate – and the Yamaha WaveRunner websites in the US and Australia only refer to a 160mm jet pump, which is the same as the previous model year.
However, it is apparent there are large numbers of 2021 Yamaha GP1800R SVHO WaveRunners with a mix of 155mm and 160mm transom plates.
The lingering question: are customers entitled to a free replacement 160mm transom plate if the feature was not highlighted prior to the sale of the craft?
Industry experts have told WatercraftZone they believe the issue was caused by a parts shortage or a parts mix-up in the lead-up to production of the 2021 Yamaha GP1800R SVHO – and was not a planned running change.
Indeed, The Watercraft Journal has posted a video on YouTube reporting that – in the US at least – the 155mm transom plate will be replaced free of charge with the 160mm version. Be sure to watch The Watercraft Journal video at the bottom of this story.
Meantime, on any other watercraft, such a hardware change may have gone unnoticed. However, the 2021 Yamaha GP1800R SVHO is a model that appeals to hardcore performance enthusiasts who sweat such details.
Industry experts have told WatercraftZone that Yamaha may have a legal standing under consumer law – and may not technically be required to replace the part.
However, mix-up or not, the industry experts also said they believe Yamaha could replace the 155mm transom plates with the 160mm design free of charge, out of goodwill.
WatercraftZone has reached out to Yamaha Australia for a comment on the transom plate issue. We will update this story with its response.