My Outboard Motor
I was encouraged to put this story up on the website during a lunch
break discussion about dodgy hardware. Mostly it was PCs but the
outboard deserves a little mention of its own.
It is an Evinrude 2.3HP 2 stroke. When we bought it in 1997, it had a
faded stop button and part of the catch holding the cowl on was broken.
The price was reasonable. This evidence of extreme age was ignored as
it was new in all other respects.
For some unaccountable reason we bought it on a trip to Sandwich in
Kent, as a part of a visit to my parents.
It worked well with the Avon Redcrest bought for £200 at a
jumble, especially after I made some rigid floorboards from marine ply.
Its early years
It looked quite reasonable until one day on a summer holiday cruise,
when it was attached to the Redcrest, as a part of a gaggle
tenders jostling against a quay wall at Fowey. It lost one of its
catches and the transfers on one side on the granite. Shock cord to the
rescue. It has worked well ever since and has proven very useful for
immediate access to fiddle with the idle screw on the carburettor.
Its Middle Age
Each time it came out and was used it got harder to start. It happened
gradually and we just got used to the starting position. Set the
throttle to start position, the choke nearly closed. Set the steering
friction lock to tight .
One hand holds on to a fixed object, the quay or a boat. The other hand
makes repeated violent movements pulling the starter cord until the
engine fires. The throttle
has then to be fiddled with as the engine changes as it warms up. Most
of the time the throttle is set too high for easy control at low speed.
Loosen friction lock to allow steering.
Once running OK it was easy to start so I would not remember
problems later .
Taking out the spark plug and cleaning it often improved the problem.
There was a suspicion that the wetness was water.
So I changed the cylinder head gasket , cleaning out salt deposits and
the problem did not really change. I did this several times. I never
took it to an outboard dealer but DIY fixed it all of the time.
2003 : final diagnosis
On one occasion after a couple of months of non use the spark
plug gap was rusty. Fairly conclusively it was water in the cylinder
A new fault emerged. Once the engine could be persuaded to start and
run with a clean plug it would run up to a high speed and then die
completely. After some more starting fiddling it would run badly ..
Some work with the idle control and the engine could be persuaded to
fire once every three or so revolutions firing just before it stopped.
In this way we staggered from Beaulieu quay outside the Abbey down to
Buckler's Hard in April. And again in Salcombe in July, where it could
just beat the tide. I think I stripped down the engine 4 or 5 times to
see if there was anything visible. Each time it would run for about 2
minutes and then die again. I suspected the ignition coil and
tried to find someone in Salcombe who would look at the engine. Nobody
Instead I bought a gasket and a new spark plug from an outboard dealer
where the spares department person's brain was fried by the high
temperatures during the summer heatwave and took several tries with a
calculator to add up the bill.
So when we got back, I went to talk to a local outboard motor dealer
who handled OMC products.
He suggested the problem with the water in the cylinder after replacing
the gasket was a warped cylinder head. This turned out to be correct.
About 0.5mm out of flat. I also discovered that the bolts holding on
the cylinder head shear at exactly 23 foot pounds torque (which is
pretty brutal) and that actually the correct torque was about 7 foot
pounds.... Had I warped the alloy head by over torqueing or overheating
, or was it bent anyway ?
So off the head went for skimming and was duly lost for a couple of
weeks by the company with the skimming machine, not the outboard dealer.
It came back and was fitted along with a Mercury head gasket which has
a kind of sealant on it unlike the Evinrude version.
The engine blocks are the same so the gasket is an exact fit. The
engine then started and ran up to higher speeds in the tank before
I also cleaned out as many waterways around the engine as possible
removing the power head from the leg, and finding some salty deposits.
I eventually rigged up firstly a timing strobe from my
petrol car days (about 10 years ago) along with a car battery and
discovered that when the engine was misfiring there was no spark at
all. I then connected a mains inverter to the battery and an
oscilloscope and monitored the voltage on the kill switch which is
across the ignition coil. I noticed that when the engine fired , the
primary voltage was always lower than a certain amount. Once this level
was exceeded the voltage would collapse randomly on each firing cycle
until the dropped and hence the magneto output voltage dropped below
that magic voltage again .
Outboard starter Repetitive Strain Injury
It is often forgotten that other things can cause RSI than PC
keyboards. Boy did I find out! With all the pulling on the starter, I
landed a severe case but it faded over a couple of weeks of stopping
using the arm for anything like typing on a PC, but instead adopting a
'thinker' pose propping up my head with it on the keyboard wrist rest.
Back to the outboard
Further discussion with the outboard shop suggested that it was not the
coil that was at fault but the condenser or capacitor. He seemed
surprised that the engine did not have a CDI unit given the purchase
date, as it should have in the late 90s. I have a horrible feeling it
is 10 years older. ....
So I got the flywheel off to get at the ignition system using
17mm socket which just happened to be the size missing from my socket
set. Quick trip up to Halfords for a new one.
I took the capacitor off and up to the dealer and he did not have one
in stock . He could not find it in the spares catalogue and so I left
the old one with him to match up for a replacement.
After a couple of weeks he said he had it in , so I went to collect it.
However it had by then been lost somewhere in the spares store at the
dealer. I am still waiting about 4 months or so since starting the
repair on the engine.... I marked the dodgy one with an X scratched on
the end of it.
So if you bought a spare condensor for an older Evinrude 2.3 and it has
an X scratched on the end then your engine will run for long
enough to check out but will die after about 2 minutes of hard running.
In the mean time I decided that one of the mains filter
capacitors (400 volt 1uF) found inside PC power supplies would do the
job. So I soldered some long flying leads on the capacitor and covered
it in hot melt glue. I then wired it in place of the condensor and
reassembled the engine setting the contact breaker gap by eye to open
about when a marker on the flywheel aligns with a mystical marker on
the engine body. I dont have a service manual.
The outboard has since run for several minutes flat out in the tank,
with an old Morris Marina spark plug . This is so long it nearly gets
hit by the piston...
Problem was I had lazily reached in with the plug spanner and crunched
the correct spark plug insulator with a quick turn of the spanner.
I have since replaced the plug with the right one.
26 thousandths of an inch gap at full opening is the correct setting
.for the contact breaker points. When I get the new condenser back I
will reset the gap.
My other Outboard
In the meantime I was given a somewhat rusty Seagull Century
longshaft. This had been last seen running 10 years ago and all the
fuel had evaporated leaving an oily brown varnish all over it. Filled
it with some fuel, tickled the carburettor and pulled the starter. It
started immediately and ran well in the tank. I think I will spend some
time cleaning off the rust and making it more presentable as an
alternative - I also could use it on a bracket on Forethought the GK24,
to give that period look and sound if ever the Yanmar fails. Most
likely it will be used to push the Pacer dinghy around the river.
Dead Again June 2004
I test ran the Evinrude engine in the tank trying to adjust the points
to get the timing right and eventually it ran up something like it
should have. Then it stopped. It would not start again at all.
When I dismantled the engine enough to get at the flywheel I
a spark but a weak one. Then I realised that the replacement capacitor
was neither short nor open circuit but lossy. I hate it.
So I went off and bought a Tohatsu 3.5, with an instruction book, a
warranty, a dinky set of tools a spare plug and split pin and shear
pin, more power and a clutch. And it goes when you want it
Now I have an outboard I can trust with CDI ignition system, and which
doesnt send you in circles when you start it.
The Evinrude joins my long list of not-working but recoverable
equipment littering the garage.
Siezed Early 2006
I turned over the engine only it wouldnt. After a lot of wobbling the
flywheel in a forceful manner the engine turned over again. I tried to
start it and I was greeted with a 'sneeze' sound when it fired. So I
put it away again.
Back again September 2006
I left my Tohatsu on a dinghy on a mooring out in the river for 6 hours
one evening and somebody nicked it. So its back to the old rubbish.
By this time the Seagull had a lot of rust inside the fuel
tank so a lot of
stainless steel bolts were thrown in and the whole thing rattled around
until the rust (and bolts) stopped coming out. Then rinsed out with
white spirit , the outside of the tank and engine block
tastefully Hammerite'd and the engine still runs. Loads of
smoke. I may well be seeing in the end of retail twostrokes with a 29
year old one running on 10:1 ... Datecode says May 1977.
I made a video of it running, and uploaded it to YouTube
. As a
result, Ian from British
Seagull Parts.com got in touch.
Back to Evinrude
The Evinrude was stripped down further and the following was found.
- Piston ring corroded to piston. Snapped as I tried to ease
As far as I can tell the bearings still run fairly well so I am going
to soak the whole lot in white spirit and re-oil before reassembly with
new gaskets and piston ring. Even if it only lasts a couple
years it gives me more of a chance to wait for the next generatiion
- Crank case contains quantity of rusty oily sludge.
- Lower crankshaft ball bearing was not properly
A roll pin that stopped the bearing rotating was found broken
crushed into the block instead of resting in a groove in the block.
- Gasket was not sealing the side of the crank case as a
Let in water from the cooling water galleries and fuel/air out the side
of the crank case. Hence the sneeze as gas blew past the piston rings
when the engine fired finally, and then the gas would come out of the
crack in the side of the crankcase.
- Cannot remove flywheel . Needs a puller ..
have replaced the Seagull with a Tohatsu 3.5 and this has worked well
until I dropped it into the river while it was running. It stopped and
I quickly yanked it out of the water by the lanyard which I alway use.
I assumed that I had killed it , as I was on the way to Hamble
Point for a lift out for Forethought I didnt have time to mess about
with it . So I left it back on the back of the dinghy and rowed out.
Once I arrived at Forethought, I realised there was still time to look
at the outboard. A few tentative pulls on the cord and I could feel
some back pressure from water in the cylinder but then I took out the
plug and pulled. No more water in the cylinder, dry off spark plug and
replaced it. Much to my surprise it worked and ran normally. So I took
Forethought up to Hamble Point and was glad of the outboard on the way
back against the tide.
I looked inside the cowling and could see
no trace of salt . It didnt look like seawater had ever been inside the
cowling. As the engine still ran well under test, I left it as it was.
month or so later and the outboard wouldnt start, with fuel dripping
out of the air intake. On stripping down I found salt/corrosion in the
carburettor float bowl - jamming the throttle full open and stopping
the fuel feed valve from closing. I cleaned the salt off the needle
valve and the bowl. Some time soon I probably should split the crank
case to see if there is still water in there.