Tohatsu MD 35B2 JET SUPPLEMENT User Manual
OWNER'S
MANUAL
MD 35B2
JET
Supplement
Copyright © 2010 Tohatsu Corporation. All rights reserved. No part
of this manual may be reproduced or transmitted in any form or by
any means without the express written permission of Tohatsu
Corporation.
GENERAL INFORMATION ......................................................................2
Before Operating Your Outboard ...................................................................................................... .2
Specifications ..................................................................................................................................... .3
Components ........................................................................................................................................4
OPERATION .............................................................................................5
How the Jet Drive Operates .................................................................................................................5
Stopping the Boat in an Emergency .................................................................................................. .6
Steering the Boat ................................................................................................................................ .6
Mooring The Boat ...............................................................................................................................7
Water Intake Blockage ...................................................................................................................... .8
Clearing A Lodged Impeller .............................................................................................................. .8
Lubricating the Driveshaft Bearing .....................................................................................................9
Operating In Freezing Temperatures ...................................................................................................9
Pre-Starting Check List .......................................................................................................................9
Operating In Salt Water Or Polluted Water ......................................................................................10
Operating In Shallow Water ..............................................................................................................10
MAINTENANCE ...................................................................................... 11
Impeller Removal and Installation ....................................................................................................11
Worn/Dull Impeller ..........................................................................................................................13
Steering Pull Adjustment ...................................................................................................................13
Impeller Clearance Adjustment .........................................................................................................13
Replaceable Jet Drive Shear Key ........................................................................................................14
Shift Cable Adjustment .....................................................................................................................15
Corrosion Control Anode ................................................................................................................. .17
Lubricating the Driveshaft Bearing ...................................................................................................17
TROUBLESHOOTING ............................................................................19
Engine Over-Speed (Excessive RPM) ............................................................................................... .19
Performance Loss ...............................................................................................................................19
ENGINE INSTALLATION .......................................................................20
Transom height of the boat .............................................................................................................. .20
Locate center line of the outboard ................................................................................................... .20
Determining the Mounting Height of the Outboard ........................................................................21
Water Testing ................................................................................................................................... .22
Index
GENERAL INFORMATION
Before Operating Your Outboard
Read this manual carefully. Learn the difference in handling characteristics between a jet drive
boat and a propeller driven boat. If you have any questions, contact your dealer.
STEERING AT LOW SPEEDS
Unlike propeller driven boats, the jet drive boat tends to lose steering control as less water is drawn
in and expelled. Increase speed slightly to regain steering.
MANEUVERABILITY
The jet drive is highly maneuverable at higher speeds, more so, than propeller driven boats. Use
caution when turning to prevent spin - outs.
IN NEUTRAL
The impeller will continue to rotate while the engine is in neutral. Although the approximate
balancing of forward and reverse thrust will minimize boat movement, the boat may tend to
move slowly forward or backward. This is normal for a direct - drive jet driven boat. The operator
should be aware of this and use caution whenever the engine is running.
Safety and operating information that is practiced, along with using good common sense, can
help prevent personal injury and product damage.
This manual as well as safety labels posted on the outboard use the following safety alerts1. to
draw your attention to special safety instructions that should be followed.
Indicates a hazardous situation which, if not avoided, will result in death or
serious injury.
Indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
2333
Watch for boat movement in neutral. When the jet drive is in neutral, the drive impeller
continues to rotate. Although the approximate balancing of forward and reverse thrust will
minimize boat movement, the boat may tend to move slowly forward or backward. This is normal
for a direct - drive jet driven boat. The operator should be aware of this and use caution whenever
the engine is running.
Specifications
Owner’s manual requires the correction. Please replace specification with below specification.
MODEL
MD 35B2 JET
Overall Lengh, in/mm
24.8/630
Overall Width, in/mm
13.6/345
Overall Height, in/mm
42.2/1,072
Recommended Transom
Height, in/mm
20.5/521
Weight, lbs/kg
196.2/89
Output
Jet power, HP/kW
35/26.1
Horsepower, HP/kW
50/36.8
Max, Operating Range
5,150 - 5,850
Number of Cylinders
3
Piston Displacement, Cu in/cc
42.5/697
Bore × Stroke, in/mm
2.68×2.52/68×64
Exhaust System
Jet Exhaust
Lubrication System
Oil injection
Cooling System
Water cooling
Starting System
Electric starter motor
Ignition
Inductive Ignition
Spark Plugs
NGK IZFR6Q
Alternator V . W
12V - 280W 23A
Trim Stages
4
Grease Driveshaft Bearing
3HT-65319-0
Gear Reduction Ratio
1 : 1
M25 Jet Drive
4
Components
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
a
d
f
g
h
i
j
k
l
n
M25 Jet Drive
a Top Cowl
b Throttle Grip
c Stop Switch Lanyard
d
Reverse Lock lever
e Shift Cable
f Drive Shaft Housing
g Thrust Rod
h Water Outlet
i Jet Drive Housing
j Battery Cable
k Reverse Gate
l Water Intake Housing
m Shift Lever
n Fuel Connecter
o Stop Switch
p Main Switch
55
5
How the Jet Drive Operates
A jet driven boat has substantially different handling characteristics compared to a propeller
driven boat. It is recommended that the operator adjusts to these characteristics by experimenting
in open water at both high and low speeds. The driveshaft driven impeller draws water up through
the water intake and then redirects it at a high pressure through the water outlet nozzle to create
forward thrust. To obtain reverse, the reverse gate moves over the outlet nozzle to direct the water
in the opposite direction.
a
c
b
a - Water intake
b - Water outlet nozzle
c - Reverse gate
When the jet drive is in neutral, the impeller continues to rotate. However, the reverse gate is
positioned so that some of the forward thrust is diverted to create reverse thrust. This approximate
balancing of forward and reverse thrust will minimize any boat movement. Because the impeller is
always rotating and creating thrust when the engine is running, the boat may tend to move slowly
forward or backward. This is normal for a direct-drive jet driven boat. The operator should be
aware of this and use caution whenever the engine is running.
OPERATION
M25 Jet Drive
6
Avoid injury resulting from contacting the rotating impeller or having hair,
clothing, or loose objects drawn into the water intake and wrapping around
the impeller shaft. Stay away from the water intake and never insert an object
into the water intake or water outlet nozzle when the engine is running.
The jet drive is always drawing water into the housing when the engine is
running. Do not operate the jet drive with the grate removed from the water
intake. Keep hands, feet, hair, loose clothing, life jackets, etc., away from
the water intake. Never insert an object into the water intake or water outlet
nozzle when the engine is running.
Stopping the Boat in an Emergency
A jet powered boat has emergency stopping capability unique to this form of propulsion.
Using the emergency stopping capability of a jet drive unit will slow down the
boat in an emergency. However, sudden stopping may cause the occupants
of the boat to be thrown forward or out of the boat resulting in serious injury
or death. Use caution when performing the emergency stopping procedure,
and be sure to practice in a safe area.
In an emergency, putting the jet outboard into reverse and applying reverse
throttle can rapidly slow down the boat and reduce stopping distance.
However, such a maneuver may cause occupants in the boat to be thrown
forward or possibly out of the boat.
Steering the Boat
The jet drive is dependent on water jet thrust for steering the boat. If the water jet thrust should
ever stop (water blockage, engine stops, etc.), the boat will slow to a stop. However, while slowing
there will be a reduced ability to steer the boat.
M25 Jet Drive
77
7
Steering the vessel in a tight turn can result in loss of boat control. In some
cases, the boat can spin out or roll over, causing serious injury or death. Avoid
steering beyond the capabilities of the vessel, especially at high speeds.
A loss or reduction in water jet thrust will directly affect boat directional control,
and may result in property damage, personal injury, or death. Boat directional
control can also be substantially reduced or lost altogether by a sudden loss
of power such as running out of gas, quickly backing off the throttle, turning
off the ignition switch, activating the lanyard stop switch, or plugging the
water intake to the jet pump. Use caution when maneuvering at high speeds
in areas where debris (weeds, logs, gravel, etc.) could be picked up into the
jet drive. The ability to take evasive action is dependent on sufficient water jet
thrust to control the boat.
While steering the boat at engine speeds above idle, the boat will respond
quickly; but, due to the relatively flat-bottom hulls and lack of a gearcase in
the water, the boat will tend to skid on turns. Turns must be started early and
use sufficient power to maintain steeringcontrol.
Mooring The Boat
Be sure to tilt the jet drive out of the water when the boat is pulled onto a beach or tied to a dock
in shallow water. Failure to do this may cause the water intake housing to fill with sand or debris
and could prevent the outboard from cranking over for starting.
M25 Jet Drive
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