Harbercraft
1875 JMAX - Review
The
test boat for this review was provided by Harbercraft and Cascade Marine in Chiliwack. Special thanks goes to Cascade Marine in Chiliwack
who has provided great support and commitment to make this review possible.
The
JMAX is Harbercraft latest jet boat design.
It utilizes the same proven pre flex technology all Harbercraft boats
do.
The
sides are made form 0.102" thick aluminum, while the bottom consists of 0.19”
thick material. Both bottom and sides
are made from 5086 Alloy.
The
boat’s MSRP is 32,225 CAD or 27,319 USD.
The
exterior is fully painted which makes the boat nice looking. The inside is Zolatone
coated unless carpeted. The floor is
plywood with vinyl.
The
hull is a delta pad design with 12 degree dead rise, lifting strakes and
reverse chines. A delta pad hull has
excellent shallow water running capabilities and produces lots of lift which
makes for an efficiently running shallow water boat. Drawback of the delta pad hull is the harsh
ride in choppy water.
The
layout of the boat is slightly different from previous Harbercraft jet boats. The windshield of the JMAX is moved further
forward as it is common with many other brands of river boats. This will give more space in the boat but
reduce the bow area.
For
a fishing boat this is a desirable setup.
For an all round boat one has to decide what is important: Bow area or
inside space.
Another
difference is the transom which is very short.
That’s a nice feature which further increases interior space.
The
pictures above show the transom with covers removed. On the floorboard one can see how short the
transom is.
Inside
the transom is the muffler and battery.
The remaining space behind the large covers can be used as storage.
The
JMAX hull length is 18’. Harbercraft offers
another 18’ Jetboat, the 1875. Those two boats only have overall length and
basic hull design in common.
The
JMAX has a wider beam with 88” and was the first aluminum Jetboat
available with the 160 HP JMAX 4 stroke motor.
The boat has a walk through windshield with 3 large glass windows. The center window functions as door and opens
to access the bow area and board the boat.
The
boat comes standard with Fishmaster seats. The boat as tested and shown has the
Sportsman package with Rivermaster seats and storage
box in the bow. The test boat came with
box seats. Standard equipment are front seats on pedestals. Which to choose depends on preference … One
has to balance dry storage with the box seats vs. more flexibility with
rotating pedestal seats.
The
left picture shows the port mid seat. On
the right is the opened hatch / step in between the
dashboard.
The
side windows are as short as in the 1875 and unfortunately not long as in the
19 foot boats which will probably allow for a little more splashing in the
JMAX.
The
The
dog house is very different as on sportjet powered
boats as it is long but low. Between the
dog house and the transom is a 10” wide walk through which allows to walk from one side of the stern to the other, which
should be great for fishing of the stern.
Unfortunately the walk through is not flush to the floor. Still this is a nice feature and allows for
much better fishing from and access to the stern.
This
design is possible due to the motor and pump layout with is long but low.
The
JMAX’ canopy is not mounted on sliding rails but rather has mounts in fixed
locations where the top can be attached.
This eliminates flimsy rails but also makes it a little more cumbersome
to put the top up and down and out of the way.
The
boat comes on a single axle Karavan trailer with no
brakes.
The
JMAX has an aluminum swim platform mounted on strong aluminum tubing which also
serves as a pump guard.
On
the stern are two welded on brackets (the one on the port side can be seen in
the picture above) where sonar transducers and zincs can easily be mounted. Mounting a fishfinder
transducer is easy on the JMAX since the pump only has one center reverse
thrust that goes straight down under the boat.
That way transducers mounted on the side of the hull is not affected but
the reverse thrust.
Helm
The
dashboard is simple and functional. Steering
and throttle is on starboard. Throttle
and thrust is controlled through a single control lever. The pictures were taken of a pre production
model and the final layout is slightly different.
The
boat has a tach, fuel gage and voltmeter. Furthermore there is a 12V power outlet in
the dash and the usual switches for boat functions, like navigation lights,
bilge pump and such. Unfortunately there
is no electronic fuel monitor available.
The
port side has a lockable glove compartment.
The hull is a walk through design and the center windows opens. There is a storage box that also functions as
step to get into the bow. Under the bow is
a small storage area that can be accessed from the inside of the boat.
Motor / Drive
The
JMAX features a 160 HP engine. The engine
is a 4 cylinder 4 stroke with 1052 cc.
Peak HP is reached at 10.000
The
chart above shows all relevant performance data of the boat, which will be
discussed further in the sections below.
There are two ground speed over rpm
curves. One for the
boat with brand new impeller and one with a severely beaten impeller.
The
motor having only 1052 cc makes it obvious that it isn’t a torque monster but
rather a motor that gets its power from rpm rather from displacement. The boat cruises at 45 KPH / 28
The
motor is derived from a motor that has been used in motor bikes and is also
being used in PWC, snowmobiles and also other fiberglass sport boats. It is however exclusive to Harbercraft
aluminum jet boats.
On
the left picture is the oil reservoir with oil dip stick. On the right the water cooled header / exhaust.
As with every 4 stroke …. The oil filter….
The
motor starts instantly as one would expect from a computerized 4 stroke motor
and idles quietly and stable. In idle,
the motor is barely audible which makes for a nice change from a Sportjet. Of course this changes
once the motor revs up. The JMAX motor hardly
vibrates and hull vibrations are very minimal.
The
graph above shows noise levels of the JMAX (red) and other Jetboats
for comparison as well as two Yamaha outboards on fiber glass boats.
The
JMAX’ noise level at cruise speed is about 88 dB. This is much quieter as a 175 HP Sportjet
which, depending on the hull cruises at about 95 or more dB.
For
comparison a typical outboard will produce 80 – 87 dB at the same speed, which
is also strongly dependant on the design of hull and motor.
The
JMAX idles at just 74 dB which gives the JMAX the typical quiet 4 stroke idle
with very little noise.
Upon
acceleration noise levels remain in the mid seventy dB. As the boat comes on plane at about 8000 rpm,
noise levels increase into the mid eighty dB and then climb up to 96 dB at wide
open throttle. The JMAX vibrates very
little, which helps keeping noise levels down.
The
JMAX noise levels are higher as a 115 HP 4-stroke and 200 HP HDPI outboards
produce but much less as Sportjet powered boats.
Unfortunately
the small and high revving motor makes for a high pitch noise that is
subjectively less comfortable as the noise from a larger motor which rev lower.
For
an aluminum inboard Jetboat
the JMAX has very low noise emissions.
Although
this is the first aluminum jet boat with this motor, the history of the motor
in motorbikes, PWCs and snowmobiles makes it likely
that this motor is mature and not prone to issues as sometimes encountered with
brand new designs.
The
pump has been used in similar form in fiberglass sport boats and shouldn’t have
“new design” issues.
The
pump has a very robust stomp grate with easy clean grate. The stomp grate is activated through a large
stomp handle on the swim platform. Rocks
and debris can easily be cleared with the stomp grate.
One
great feature of the pump is the ability for clearing out debris that is lodged
onto the impeller or impeller shaft is a port inside the boat through which the
impeller can be accessed and sucked in ropes or plants be removed. Being able to remove debris from the impeller
from inside the gives the operator some peace and should make navigating the
boat in weeds much easier. Sucking up
ropes and water plants with the JMAX should be more an inconvenience than an
issue.
From
left to right: The pump with access closed
port, close up of the access port. On
the right is access port opened with access to impeller shaft and
impeller.
The
pump has a reverse gate with a single bucket that directs the reverse thrust
down under the boat. The single reverse opening is located below the nozzle and always open. It produces thrust by the reverse bucket
being lowered to cover the jet stream that then goes down and forward through
the reverse opening.
On
the left: The reverse bucket open for forward thrust. On the right: The reverse bucket closed for
reverse thrust.
This
design works amazingly well for the size of reverse gate but does not achieve
the reverse thrust of a Sportjet. The
reverse gate was however prone to jamming from small pebbles that wedge in
between the bucket and the nozzle when in reverse. It then requires manual intervention to free
the nozzle which is otherwise stuck in reverse.
Performance
The
boat has adequate power for its size. One
has to be aware however that with 160 HP it is not a power monster but rather a
reasonably but not overpowered boat.
Still
the boat feels agile and at no time underpowered with 2-3 people and light gear
on board. The boat comes
on plane easily and accelerates quickly. Boat handling is much like one expects from a
Harbercraft hull. It turns sharp and
quick and easily. One always feels safe
in the boat.
Typical
for a jet boat is the rooster tail. It
is not shooting up but sprays straight back.
The
boat reaches a top speed of 66.7 kph or 41.5 mph,
which is slightly less than a 175 Sportjet, which will reach about 70 kph or 43.5 mph in a similar size boat. The 175 Sportjet being faster is no surprise
as more peak HP means less more speed.
The
small difference in top speed between the JMAX and a 175 Sportjet is rather
small and hardly a concern.
Fuel Consumption
Unfortunately
it was not possible to get fuel readings of the test boat. It did not have an electronic fuel meter nor a flow meter. Hopefully
Harbercraft will be able to offer an electronic fuel use gauge in the
future.
Data
in this review is based on fuel consumption values that are available for the
160 HP motor.
Since
those are not values measured with the test boat all fuel use information in
this review shall be used and treated as an estimate only!
The
graph shows the fuel consumption over speed for the 18’ JMAX compared to an 19’ Harbercraft 1975
with 200 Optimax Sportjet.
The
JMAX cruises at respectable 0.4 l / km or 6 MPG. This is a good value for a Jetboat
and better than a 175 Sportjet.
This
should give the JMAX a theoretical maximum cruising range of 340 km /
210 miles with its 130 l / 35 US gallon tank.
As with any boat one should never plan trips based on this theoretical
cruising range as factors like wind, waves and current can drastically reduce
the actual range.
When comparing fuel use to a 200 Optimax Sportjet it does seem like the JMAX
should do better. The only fuel use data
is available for a Harbercraft 1975 with 200 Optimax Sportjet. In the longer but narrower 1975 the Optimax
delivers very similar fuel use of 0.42 l / km or 5.7 MPG while delivering 20%
more horsepower.
Again,
the fuel consumption for the JMAX was not measured and is based on published
values and as such should only be seen as an indication.
The
fuel consumption of the JMAX is very good and will allow one to use the boat
without worrying too much about fuel cost.
Acceleration
Unfortunately
no performance data for a Harbercraft 1875 with a 175 Sportjet was
available. The only available acceleration
data is for an 18’ Thunderjet with 175 Sportjet and a
Harbercraft 1975 with 200 HP Sportjet.
The Thunderjet is a good 500+ pounds heavier
and so one should take this in mind when looking at the data.
The
JMAX accelerates quicker off the line until into the mid 30 KPH. Then the stronger 175 Sportjet pulls
away.
This
data is pretty much as expected … the lighter boat with slightly less HP will
get off the line quicker. Quick off the
line acceleration is important for a Jetboat.
For
comparison data from a Harbercraft 1975 XL with 200 HP Optimax was added. As expected this boat out accelerates both
other boats by far, even though during the test it was loaded heavier and was
running an old impeller.
For
a river boat one would prefer quick off the line acceleration for maneuvering
shallow rivers and for getting the boat on plane as quickly as possible. This puts the JMAX ahead of a heavier boat
with 175 HP Sportjet.
Ride
Ride
is pretty much as one would expect from a 12 degree delta pad hull. The boat comes on plane quickly and handles
the occasional wake from other boats and small waves well but it is clear that
this is not the boat to tame the kind of chop that is usually found on big
lakes. This boat is not a “Heavy Chop
Tamer” but heavy chop should not be encountered on the river waters the boat
was designed for. Since the boat is
quiet heavy it should be acceptable to tackle lakes with it as long as one
doesn’t expect deep V glass boat ride quality.
As
with all boats the JMAX is a compromise and does great in shallow water but of
course this comes at the cost of rough water handling.
Being
designed as a river boat, the JMAX does exactly what it was intended to.
Conclusion
The
JMAX is a nice addition to the aluminum Jetboat
market.
The
motor / drive combination works very well with the boat and is quiet and fuel
efficient. The JMAX motor is the only mid
range power 4 stroke inboard Jet available today. The options are 2 stroke Sportjets
or V6 or V8 inboard jets. The latter
have more power but use more fuel and are considerably heavier.
The
JMAX is a great efficient mid size river boat.
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