Yanmar 3GM30F
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Friday 15th February, 2002. Yanmar 3GM30F delivered.

The 138Kg Yanmar engine seems very light in comparison to the Bukh DV20 which weighed in at 210Kg. The Operators Guide is excellent and I ordered the Workshop Manual which in comparison to the Bukh, at three times the price, is good value.

The lifting lugs are well positioned and enabled the engine to be lifted directly into the boat. The engine was positioned on the cabin sole prior to positioning in the engine compartment. The engine was delivered on time, albeit with a B type control panel rather the than the latest B2 (with hour meter).

The photograph on the left shows the engine compartment after removal of the Bukh and prior to modification of the engine bearers. The large anti-vibration mountings that come with the Yanmar require the bearers to be reduced by approximately 70mm. The new engine will require extended throttle and gear control cables together with an engine stop cable.

Not a job for the feint hearted! A power saw made fairly light work of removal of the bearer, although it was difficult to keep the cut across the bearer level. The infill within each bearer is solid foam of which 70mm was removed  with a sharp chisel. A mask and powerful vacuum cleaner are essentials!

Next on the list for modification of the bearers was to insert hardwood supports. Mahogony blocks 565 x 69 x 69 were made and 'nudged' into the correct alignment before bolting through using M10 coach bolts with large washers and Nyloc nuts. Height and alignment with the centreline of the propshaft took account of the need to sheath the Mahogony with glass fibre. The steel bearer plates are to be mounted on the glass fibre.

To manipulate the engine in and out of the engine compartment is achieved using a block and tackle attached to the main halyard. This in turn is controlled longitudinally by use of one of the reefing lines attached to the rear of the boom.  The blocks used were 'three purchase' with a jam cleat mounted on the top block to enable hoisting the engine by pulling down on the line.

Sunday 17th February, 2002. The photograph on the left shows the engine ready to be lifted onto the modified bearers once they have been sheathed in glass and given a coat of bilge paint.

Thursday 20th February, 2002. Mahogony bearers sheathed with three layers of glass fibre. This will be left to cure and then a final gelcoat will be applied.

Photograph on left showing Anti-vibration mountings bolted to locally manufactured bearer plates. These will be secured to the engine and the yachts engine bearers. They were necessary to account for the reduced width of the Yanmar compared with the Bukh.

The bearers given a final coat of paint, are ready to be assembled on the engine and then bolted to the yachts engine bearers once the engine has been aligned, give or take a couple of 'thou', with the prop shaft. Final alignment can be achieved using the AVM bolts. 

The final gel coat applied. The bearer plates remain to be fitted and then the engine will be positioned into place. Then the length of the prop shaft and the control cables will be calculated.

The engine is finally positioned and bolted to the yachts bearers. All that remains in the alignment process is to statically align the engine with the prop shaft, using feeler gauges between the prop shaft and engine drive flanges. The gap should be the same all round the flange and if one flange is rotated in 90 degree steps the gap should remain the same.

Although the connection between the gear and prop shaft will be via a flexible coupling, alignment is carried out by easing the prop shaft back toward the engine so that the gap is relatively small enough to insert feeler gauges.

The photo on the right shows the feeler gauges in use, checking the all round gap between the two flanges.  Once all adjustments are made, the prop shaft will be eased back and the flexible coupling will be fitted between the two flanges. Because the flexible coupling is made from non-conducting material an earthing strap will be inserted to make contact with each flange. 

Just to be sure of the alignment a dial gauge indicator was used to check the relative position of the flanges through 180 degrees. 
A new Volvo shaft seal is to be fitted before the boat is launched, taking note to bleed the air from within the stern tube when the launch takes place.

The moment to wait for! The new Autoprop is assembled onto the new 25mm prop shaft which was machined with the ISO standard taper. Loctite was used on the brass shaft nut which was torque tightened. The nut was also drilled before tightening the grub screw, to which Loctite was applied. 

A new Cutlass bearing was fitted into the 'P' bracket and the new 'Spurs' rope cutter fitted to the shaft. The stator of the rope cutter was secured to the 'P' bracket using three M8 hex headed bolts using Loctite. Click  Autoprop to see the video. It may take a little time to download.

The shaft was carefully cut to length to ensure that the cutter was correctly aligned with the stator and the shaft flange was then secured to the shaft.
The flexible coupling was then fitted between the two flanges and the bolts tightened. Not shown is an earth link connecting the shaft flange to the engine flange. 

A new salt water filter is fitted, just above the water line, to allow for clearing without any major mess. The fresh water cooling expansion tank is visible to the rear. A new control lever and cables will be fitted together with the electrical harness and fuel feed and return pipework. A new type B2 engine control panel is expected to be delivered which will be customised to fit the existing housing sited in the forward end of the cockpit. 

The engine was delivered with a A-Type panel then the old B-Type before finally getting my hands on the new B-Type. Although the panel includes all components; switch panel, tachometer with hour meter and the warning light module, to fit the existing recess the panel required that the components be split. The photo shows the switch and warning panel fitted into the existing recess. The tachometer and hour meter is mounted adjacent to the chart table. 

Fitting the cable is very simple. Just connect the matching plugs and sockets. However, there are unused cables and plugs behind the panel and on the engine. These are for optional equipment and for a sail drive alarm when fitted.
In the Fulmar there is little over a metre between the control panel and engine mounted plugs, therefore the three metre long cable has to be shortened. The cable was bundled and tie-wrapped alongside the existing wiring loom.
The tachometer and integral hour meter is mounted just above the main circuit breaker panel adjacent to the chart table. Fortunately, no extra cabling was necessary between the other control panel components.
The Boss, Christine, arrives for inspection of the completed fitting of engine, Autoprop and 'Spurs' rope cutter. The inspection complete, Christine set to and polished the hull with its annual Farecla waxing. Just one or two minor jobs like filling the engine cooling water, engine and gearbox oil, and launching then we'll be in business.
The two photographs on the left show the Vetus watertrap in position just beneath the water tank. It is sited far enough back to enable future access to the stern tube and Volvo seal.
The outlet from the watertrap is led away to the outlet on the transom. The exhaust hose is looped up toward the deckhead before being led down to the transom exhaust outlet.
The photograph on the left shows the rear of Morse control. The left hand cable controls the gear box and the centre cable the throttle. The cables should be kept free from tight bends and the throttle cable allowed to move freely on the lead to the Morse control. On the front of the Morse control it is possible to adjust a 'break' to counteract any spring action of the engine controls.
Tuesday 26th March 2002. Finally, this photo shows the brass end fitting of the throttle cable. The cable must be screwed into the end with the circlip and spring. Below the throttle is the engine stop lever, painted yellow to enable quick identifying if required. I have painted items which need to be identified at short notice with yellow paint and these include the two fuel bleed points, on the top of the fuel filter and injector pump, the bolts holding the salt water pump in position and the fuel pump manual operating lever. The boat is launched and the Volvo seal bled of air before the engine is started in the water for the first time. 
Pleased to say that everything seems A-OK.
Easter weekend. The good weather meant cleaning the interior of the boat was made easier with the added incentive of taking a trip to Yarmouth on completion.  
Boat speed  at 2500 RPM is 7 Knots. The next report will be on completion of the all important Pre-Delivery Inspection (PDI) 
Warranty inspection completed. Recommended to install an anti-siphon device which is shown. This has been installed well above the waterline (400mm minimum) to prevent cooling water entering the engine, even when heeling. It is also worth a mention to say that periodic maintenance of the device is required to prevent clogging with salt crystals. 

June 2003 after experiencing some vibration when reducing speed and also  resonance a set of mountings produced by Yanmar Australia were fitted. 

The results were excellent and no further vibration or resonance was apparent. 


This page was modified on 18 September 2018 11:08 by Richard Spencer.