A Pump Worth Saving - The Story of How WATERAX Kept the 185cc Alive

The story of how the MARK-3® 185cc almost disappeared in 2014 — and what WATERAX did about it.

When WATERAX announced the discontinuation of the MARK-3® 185cc in April 2024, the reaction in some corners of the firefighting community was immediate: WATERAX abandoned the 185cc. WATERAX moved on. WATERAX chose the new pump over the trusted one.

That reaction is understandable. It is also missing half the story — the half that changes everything about how the discontinuation should be read.

The full story is this: the MARK-3® 185cc came within reach of disappearing in 2014. Not because WATERAX decided to move on from it. Because the company that made its engine decided to stop making it. ROTAX — whose engine had powered the MARK-3® since the 1960s — was discontinuing that engine.

What happened next is the part of the MARK-3® story that almost nobody knows.

2014: The Engine That Was Going Away

The MARK-3® 185cc had run on a ROTAX-derived engine for the better part of fifty years. That engine was not something WATERAX designed or manufactured — it was something WATERAX's predecessors had sourced, adapted, and built the pump around. The relationship between the pump and the engine was a deep one, but the engine's future was not in WATERAX's hands.

When ROTAX made the decision to discontinue that engine, the implications were stark. No engine means no MARK-3® 185cc. The pump that had become the global standard for wildland firefighting — trusted by the US Forest Service, CAL FIRE, every Canadian province's wildfire agency, and agencies in over 50 countries — would simply cease to be available. Not because it failed. Not because something better had replaced it. Because its engine was being discontinued by a third party.

For the agencies that had built their entire water-moving infrastructure around the MARK-3® — tens of thousands of pumps in service worldwide, hose lays and relay systems and procurement processes all calibrated to this specific platform — the prospect of losing access to new units and eventually to spare parts was a genuine operational crisis.

The Decision: Acquire, Improve, and Buy Time

WATERAX acquired the intellectual property and the manufacturing rights to the 185cc engine from ROTAX in 2014. This was not a routine business transaction. It was a commitment to an engine that the original manufacturer had decided had no future — and a bet that the firefighting community that depended on it deserved better than a quiet disappearance.

Taking ownership of the engine IP meant taking on the full engineering, manufacturing, and quality responsibility for a fifty-year-old platform. It also meant the freedom to improve it.

The first thing WATERAX's engineers did was upgrade the cylinder to a Nikasil coating — the same hard, heat-resistant treatment used in high-performance motorsport engines. The result was a meaningfully better 185cc engine: improved wear resistance, better heat dissipation, extended service life. The upgraded MARK-3® went back to San Dimas and passed the USDA Forest Service 100-hour endurance test on August 4, 2015 — requalified under QPL 5100-274e with a new certification.

The pump that agencies had trusted for decades was not just preserved. It was made better.

What the 2014 acquisition actually meant for the 185cc:

• Every MARK-3® 185cc sold from 2015 onward ran a WATERAX-manufactured engine — not a ROTAX engine.
• The Nikasil cylinder upgrade extended engine service life and improved heat performance across the entire installed base.
• QPL requalification in 2015 confirmed the upgraded engine met or exceeded the original standard.
• Genuine spare parts guaranteed for a minimum of 10 years from April 2024 — support running through at least 2034.
• Without the 2014 acquisition: no new 185cc units after 2014, and a parts cliff that would have followed shortly after.

The Decision Made at the Same Time: Build the Successor

Here is where the two stories converge. The decision to acquire the 185cc engine IP and the decision to begin developing its successor were not separated by years. They were made in parallel, by the same team, at the same time.

Because when you take ownership of a fifty-year-old engine that another company was walking away from, you understand something very clearly: you have bought time. The platform can continue. It can be supported. It can be improved at the margins. But the fundamental architecture of a 1960s engine has limits that no amount of Nikasil coating can overcome — limits of weight, of starting behavior, of adaptability to a more diverse firefighting workforce with a longer, harder fire season.

The Watson Edition development program began in that context. Not as a replacement conceived after the 185cc had run its course, but as the long-term answer to a question WATERAX had taken responsibility for in 2014: what does the MARK-3® platform look like in the next generation, built for the firefighters of the next generation, on an engine that we design ourselves from the beginning rather than adapt from someone else's discontinued product?

That development program took years. The engineering team spent more than five years conceiving, designing, prototyping, testing, and re-testing the Watson Edition before it was shown to a single firefighter outside the company. The first public tour was in 2019. Commercial production began in 2022. QPL qualification was achieved in August 2023.

The timeline looks like this:

What the Full Story Actually Says

The narrative that WATERAX abandoned the 185cc gets the sequence exactly backwards. WATERAX is the reason the 185cc was available from 2015 to 2024. WATERAX is the reason agencies could continue ordering new units, training new crews on the platform, and maintaining their existing fleets for an entire decade after the engine's original manufacturer stopped making it.

The discontinuation announced in April 2024 was not WATERAX walking away from the 185cc. It was the end of a ten-year stewardship — a commitment honored in full, with a successor ready, with parts support guaranteed for another ten years beyond the final unit.

And the Watson Edition — which some read as the pump that replaced the 185cc — is more accurately described as the pump WATERAX built so that the MARK-3® platform would never again be dependent on a third party's decision to keep making an engine. The Watson Edition's 140cc engine was designed from scratch, by WATERAX engineers, for exactly this application. Its future is not in anyone else's hands.

For Agencies Still Running 185cc Fleets

If your agency has a fleet of 185cc pumps in service, the end of production does not mean the end of support. WATERAX's commitment is clear and specific:

• Genuine spare parts for the MARK-3® 185cc will remain available for a minimum of 10 years from April 2024 — through at least 2034.
• The Watson Edition is fully compatible with existing MARK-3® water-moving systems — same fittings, same hose standards, same relay configurations. Fleet transition does not require infrastructure replacement.
• The Watson Edition and the 185cc are the only two pumps in the world currently QPL-qualified under USDA Forest Service Specification 5100-274e. Both certifications required the same 100-hour endurance test at San Dimas.

The transition from the 185cc to the Watson Edition is not a forced retirement. It is a managed handoff between two generations of the same platform — one that WATERAX has been preparing for since 2014, and one that your agency can make on your own timeline, with full parts support for the fleet you already have.