DIY Marinisation guide
- Determine the power that you require from your new (slightly heavier)
diesel engine, by reference to performance on your existing gasoline power, or
from the Lancing Marine computer. Remember that gasoline engines may give
30-40hp less than their model numbers might indicate.
- If your required swap is shown on the spreadsheet
on page 22 of Pricebook, you can be reasonably sure that the job is technically
- Check that you have enough room for the new engine(s) by reference to the dimensions on pages 6 & 7, or measurement of your proposed engine.
- Ask Lancing Marine for final advice.
- Remove drive cover and disconnect control cable. Remove steering pivot
screw, rubber bellows and clamps.
- Support drive and remove lock screws. Drive pivot pins inwards into bellows
area using a suitable drift and a 2lb. hammer.
- Pull drive aft to disengage drive line. Early type 100 drives will dump their oil if
laid on their sides.
- Support engine with hoist. Remove 6 bolts and 3 locktabs from around the
outside of the driveshaft housing. Grease the three holes now exposed and
insert 3 of the bolts into these holes, and tighten to 50 lbs-ft.
- This should jack the lockring off of the driveshaft housing. Heating lockring
with gas torch may help.
- If this proves difficult, consult Lancing Marine for further advice.
- Remove nuts and washers from outer ends of trim rams and pull rams
sideways to disengage.
- Shift gearshift into forward gear and remove 6 stainless nuts on back of
upper gear case.
- Take the weight of the drive on lift eye with a rope from above.
Lift the leg part way and drop it down. This should cause the upper unit to
kick out and disengage the drive line, allowing the whole unit to be pulled
out of the transom shield.
- Undo two rear engine mount bolts. Nuts should be captive in the inner
- Disconnect battery cables from engine and battery
- Disconnect fuel hose and ensure that it cannot spill fuel.
- Disconnect water inlet hose and exhaust outlet hose(s).
- Disconnect wiring harness at multi-pin plug.
- Disconnect control cable(s) fixed to engine.
- Disconnect any extra items connecting engine to boat.
- Disconnect front mounts from the hull. (if present) Lift
engine forwards and upwards with suitable lifting equipment. Take care of the
Mercruiser’s rear mount washers.
- Review your compitance, capability and equipment to complete this task.
- Review Lifting Operations and Lifting Equipment Regulations 1998 (LOLER) https://www.hse.gov.uk/work-equipment-machinery/loler.htm
- Remove wiring harness from engine, together with senders.
- Remove flywheel housing from engine.
- Remove Mercruiser coupling from engine.
- Remove exhaust connection from transom shield if a blanking plate is to be
ASSEMBLY AND INSTALLATION
- Follow guidance notes supplied with engine.
D-I-Y kits contain all marinisation and
modification parts and certain Lancing Marine services needed to complete
ex-vehicle engines to specifications similar to those of our completely
The engine swaps listed are the more popular ones, but others can be
quoted on a one-off basis. Whilst every attempt is made to ensure 100%
compatibility, there may be variations of makers’ specifications or
boatbuilders’ installations that we have not foreseen, in which case we will
try to vary the parts we supply at least possible cos.
installation photographs will often help us to customise the equipment we
supply at minimal extra cost.
Fuel tanks that are galvanised or zinc plated inside must have their
interiors protected from the effects of diesel fuel, owing to its high sulphur
content. Diesel engines to be used on inland waterways require fuel system
A higher standard of fuel filtration is required for diesel engines than for
gasoline, so we suggest the fitment of our pre-filter with water separator.
If we are building an engine for you, the
following parts need to be sent with your order to Lancing Marine for
modification or installation on the replacement engine:
- Flywheel housing
- Engine half wiring harness
- Temperature and oil pressure senders
- Flywheel coupling
- Power steering pump and mount
- Exhaust connection from transom shield, if modification is required, or
blanking plate to be made.
IF IN DOUBT, ASK LANCING MARINE FOR HELP
Do’s and Don’ts of D-I-Y Marinisation
- First try to establish just how much power you need in order to obtain the
performance you require from the boat that you wish to power, either by
asking the original boatbuilder or by using Lancing Marine’s propeller and
speed calculation computer program.
- Look for engines of suitable power that also appear in the pricebook, and
avoid non-listed engines, as you may find marinisation parts for them
- Try to obtain engines that are still in good running order, either from
crashed vehicles, or from M.O.T. failures. Don’t buy an engine that is not
in running order, as it is often more expensive to repair a worn-out motor
than to buy a brand new one.
- Always ask to see the engine run before buying it. Watch for white or blue
smoke from the exhaust, fumes blowing out of the oil filler, and listen for
knocks, especially on the over-run as you blip it, and at idle. These are all
portents of potential disaster. Look at the oil on the dip-stick and if it is
very black and sludgey, the piston rings may be badly worn.
- Before stripping any parts, give the engine a good scrub with a degreaser (Jizer) and
hose it off. This makes the job much more pleasant. Then remove external
automotive parts that will not be re-used, and drain the engine oil.
- Lay the engine on its side, or stand it on end on its flywheel, taking care
that it will not fall over, and remove the sump. Examine the residue in the
sump for metal particles, and odd parts that may have fallen off. If you
find anything like this, start worrying . . .
- Remove bearing caps and examine bearings and journals, push feeler
gauges up between the piston skirt and the bore to measure the wear,
and examine all the lobes of the camshaft. If you find any serious
damage or wear at this stage, reject the engine and ask your supplier for
a better one, as it is a lot cheaper to start on another one than to try to
repair serious faults.
- Reassemble the engine, do normal service checks, and fit the
marinisation parts, gearbox, mountings, etc. If you have any problems in
this respect, then phone Lancing Marine for advice.
- Prior to installation in the boat, fill up with water and lubricants, connect
up a fuel supply, battery cables, and fit on your exhaust hose, and
silencer if you have one, so that it dumps into a clean tank. Fill the tank
with water and connect a hose from the tank to the water pump pick-up.
- Make sure the engine cannot fall over, and fire it up. Check oil pressure
as soon as it starts and run it for long enough to get well warmed up,
checking for leaks and unusual noises, and re- checking the oil pressure.
Take time over testing, as it is much easier to correct faults whilst the
engine is out of the boat, than it is once it has been installed.
- “Whatever happens do not panic. Instead call us on