Hamilton Jet HJ212 Installation And Service Manual page 78

Maintenance
Checking the steering
Refer to drawing: HJ21206000 Steering Assembly.
The HJ212 jet steering nozzle system has been designed with minimal clearance between the
nozzle and the nozzle housing. This gives optimum steering thrust at any lock. It is important
to keep the pivot bushes and pins in good condition to maintain this clearance.
Heavy impacts may deform the nozzle or nozzle housing causing the steering to jam.
The steering system should be checked for freedom of movement.

Inspect the steering cable and make sure it moves freely. If necessary disconnect the cable to check for
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fraying of the cable. The cable should be greased when refitted.
The cable attachment points, and the cable outer mount points should be inspected to make sure they

are secure. This is particularly important as failures can occur if these items come loose.
Check the play in the steering shaft [1], it should have a running fit in the bushes [3], [4] and [15] with no

tendency to bind. Lightly grease the bushes and shaft. Inspect the steering shaft seal [2] look for signs of
leakage, or by assessing lateral play.
Make sure the cotter pin [5] has the nut torqued correctly. Refer to section: Tightening Torques on page

10-28.
Check for freedom of movement between the steering crank [4] and the nozzle bush [15].

Check for excessive wear of the crank ball. The maximum clearance between the ball of the crank and

the nozzle bush is 1.2mm (0.047ins).
Check that there is clearance between the stem of the crank [4] and the top of the nozzle bush [15] at full

lock in both directions. If jamming occurs, the steering assembly must be dismantled and examined for
damage.
Check the nozzle for any sign of bending or cracking on the underside of the steering arm. If this has

occurred the nozzle is not safe to use and must be replaced.
Ensure the nozzle [16] turns freely in its mount.
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Inspect the bowl of the nozzle housing [9] for excessive scoring inside. The clearance between the rim of

the nozzle [16] and the nozzle housing [9] should be approx 0.5mm when new. Some performance is lost
when this gap is over 1.5mm.
Inspect the nozzle housing [9] for damage.

Ensure that there is no detectable free play (less than 0.4 mm total lateral movement) in the nozzle

bearings. Should there be any play, it is a possibility the nozzle [16] may bind in the nozzle housing [9].
The nozzle housing bush [10], o-ring [11] and pivot sleeve [13] should be replaced.
Make sure there is vertical play of 0.1 to 0.4mm between the 3mm washers [14] and the flanged bush

[10] fitted to the pivot pin bores in the nozzle housing [9]. If there is no play detected, the washers [14]
may be binding. If there is too much play the nozzle rim could bind inside the nozzle housing [9].
There should always be 0.1 to 0.4mm vertical clearance between the nozzle and the inside of the nozzle

housing [9]. This ensures the nozzle does not bind in the nozzle housing [9].
Ensure that the pivot pins [12] are tightened to the specified torque (40Nm {30ft/lbs}). Should these

bolts come loose the steering could jam. Do not over tighten the bolts as this can cause the steering to
be stiff by clamping the washers [14] on the nozzle housing [9].
Check that the tiller stop is adjusted correctly and that the securing nuts are tight. The clearance
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between the nozzle and steering housing should be the same in both directions. Adjust by loosening the
nuts and sliding the tiller stop sideways as required.
8-16
Installation and Service Manual