Outboard stalled in surf

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chilliboy

New member
Hi guys, need some outboard advice from the experts...

Went to St Lucia this morning for a bit of spearfishing but my outboard (yamaha 50hp 2 stroke on a C-ski 440) stalled on me twice in the mid break right after punching through about a 1.5m wave and the boat being almost vertical. It started 1st pull after each stall but after it happened the 2nd time I turned around and decided today is not my day and if it stalled in the backline which was huge I would 100% flip the boat plus the waves looked a lot bigger once we got in the water. The big commercial boats did launch although the skippers looked a bit nervous. Swell (from Richards Bay Weather buoy) was 1.8m, 10s, SE.

Anyway I have launched many times at Vidal, Sodwana, Maphelane etc. without any problems and the motor has never stalled. Usually we are fair weather divers and do not push our luck too much and I almost saw my ass this morning when I pushed a little too hard.

 - As far as I could tell the motor did not submerge (would it start so easy if it did?)

 - Fuel supply seemed fine and I did properly warm up the motor for almost 10min making turns waiting for a gap.

 - Can/Will an outboard stall if for instance you apply a lot of throttle to punch a wave and before you can reduce the throttle the motor cavitates and maybe over revs?

 - St Lucia is full of sandbanks so even when you think you are deep you might not be that deep. So will an outboard stall if you open the throttle and the prop gets pushed into the sand briefly as the bow lifts?

 - Will an outboard stall from the whiplash/jerk when you go over a wave (unlikely I think as this happens often)?

Sorry if this is a bit vague but stuff happened very quickly so I am not to sure if motor submerged/prop into ground/cavitate etc. So all in all a big fail of a day but I got new respect for St Lucia and I don't have to tell anyone’s wife that her husband is in the morgue, so not to bad I suppose.

Thanks
Karl
 
K

kennylau

Senior Member
Hi Karl

The possibility of your outboard stalling after it hit sand while in gear is a big possibility. I assume it was revving high and as you said, you were vertical...it might have been that with the falling back part, it went to deep into the sand and then stalled.

Let us hope that it did not submerge fully, otherwise the procedure would be the same as "de-capsizing procedure"..but I doubt this as she started immediately without problems. How long was she under the water? Should only have been split seconds.

I don't think anything else could have caused it to cut out either as all your pre-checks were done and she was fine. I would go for the first possibility. Is your props still fine?

My 2c.

::tight:
 
I

IWyk

Sealiner
A bit more information would help. What setup do you have(tiller, center console?)

Normally motor should not stall when launching(rough launch, hitting some sand etc.)

St Lucia has a long back line(you think you are through and then something stands up again) and as you mention many sand banks at times.

Normally if it is a fuel problem the motor would not start on the first pull after the stall. Especially not twice in a row.

My first ques would be some loose electrical connection. Kill switch would be the first one to check, clean etc. then on the motor the bolts holding the electrics normally have double as place where the earth wires are connected.

Any loose connection could cause the motor to cut when punching the wave as the boats nose goes up especially as you mention you almost went vertical..
 
Could then be that as soon as the boat is then again in the normal position that the loose wire makes connection and she starts.

This is where I would start trouble shooting. I would also make sure I find the fault as it will only get worse and more risky, especially as you are only using one motor.

I also have a small boat(Skivee 500) and more often than not don't launch when things are iffy, rather stay ashore and wait for a better day.

You made the right decision to beach after the stalls.

Hope this helps, good luck
 
T

thika

Sealiner
It happened to me two years or so ago

I came out from behind the harbour wall and a set of near breaking big waves was upon me from starboard

Only had time to turn and press against about four of them, one directly upon the other. The boat was also near vertical as the swell was really big (like coming over the harbour wall)

Only when the last one had passed underneath I realised my one motor was dead

I was at low revs only and I think the stall had something to do with the angle of the floats/fuel level in the carb bowls
 
C

chilliboy

New member
Thanks Guys. I think IWyk hit the nail on the head with the kill switch or electrical problem. Stopping the motor dead like that without stuttering or anything else and then starting like nothing was wrong feels exactly like when you pull the kill switch. I have not considered this but I think it might be the problem.

The boat is a 4.4m centre console with a 1995 Yahama 50hp on. It has a kill switch on the outboard and I also added one on to the throttle control (2 years ago). I never use the one on the outboard and the kill switch is permanently plugged in. That switch is quite old and I might just disconnect it.

I will also run the motor and then lift it up to see if it stalls. Maybe a carburetor issue but I would not expect this to cause the motor to die if lifted for a fraction of a second (I do not have trim and tilt and leave the motor lock off always). An electrical problem however could very well kill it from the impact/shock or tilt.

I do not think the prop hit the sand and stalled the motor as I can not see any damage on it. Also if it only happened once it could have been the prop hitting the sand but twice in a row is unlikely.. I have hit sand a few times at low revs and it has never stalled the engine.

Will see if I can figure out the problem this afternoon and report back.
 
C

chilliboy

New member
Another Question. Is it better to lock your engine down or leave the lock off? I always leave the lock off in case I hit something and for beaching. But would it not be better to lock the motor once you are in deeper water but before you actually tackle the surf?

With the lock off you run the risk that as you go over swell and ease down on the throttle or if the engine lifts out of the water the engine slaps against the transom (which seems more and more plausible to me). With the lock on you damage motor and transom if you hit something...

Is there no midway? i.e lock it down with something that will break off easily before you can do damage to your motor or transom. Does an engine with trim and tilt and beach kit still have this problem, I suppose not?
 
I

IWyk

Sealiner
chilliboy wrote:
Another Question. Is it better to lock your engine down or leave the lock off? I always leave the lock off in case I hit something and for beaching. But would it not be better to lock the motor once you are in deeper water but before you actually tackle the surf?

With the lock off you run the risk that as you go over swell and ease down on the throttle or if the engine lifts out of the water the engine slaps against the transom (which seems more and more plausible to me). With the lock on you damage motor and transom if you hit something...

Is there no midway? i.e lock it down with something that will break off easily before you can do damage to your motor or transom. Does an engine with trim and tilt and beach kit still have this problem, I suppose not?
Click to expand...
Always locks off, never attempt launching or beaching with locks on!

Big problems if you have locks on and hit a sand bank or anything else for that matter(logs, floating debri) This could cause serious damage to the lower portion of the motors(gearboxes) and will also cause serious damage to the transom as something has to give. I saw a guy in Moz coming back in, (with a brand new boat), first time at the venue, take both his gearboxes off when he had locks on and came in too close to the rocks hitting a submerged one.

If your timing is right and you ease off the right amount at the right time you should not have any issues with the engine slapping the transom often. If it happens occasionally the transom can handle that.
 
I

IWyk

Sealiner
I would start with bypassing the kill switch on the motor.(probably the original) one as the engine may have originally been a tiller. Use only the best marine lugs/connectors and replace all the wiring related to the kill switch. As mentioned check all the wires that are earthed on the motor(take off clean, lubricate with non silicone based anti corrosive spray and put together properly)

The last thing you need is to lose confidence in your motor when launching.

Good luck.
 
L

Limpopoking

Sealiner
IWyk wrote:
lubricate with non silicone based anti corrosive spray
Click to expand...

I'm curious as to why non silicone?... I was under the impression that silicone grease is one of the best anti-corrosives for electrics. I've been using dow corning silicone grease for years... What's the reasoning IW?
 
I

IWyk

Sealiner
It does little. It is a poor lube, a poor rust preventive, and a poor water sealant. It is good for lubing rubber items. It forms a dry film on everything and can actually also trap moisture underneath itself.

Silicon has the nasty habit of creeping into everything. If it ends up in electrical contacts it can create serious problems.
Sometimes a poor connection is actually caused by a well meaning person trying to help the problem by using cleaning sprays that contain silicones to make the connections water-repellent. Why is this harmful? This is because silicone when certain conditions exist, can combine with metal ions to form high resistive films such as sodium silicate."
and this then acts as an insulator and the contacts will no longer carry electrical current and it is very difficult to get rid of the coating.
Rather use a electrical grease or even "copper slip" grease on and over all these connections.

I bought two bicycles for me and the wife(cruiser type) and even the salesman said to use spray on the spokes etc.(but not silicone based).
 
L

Limpopoking

Sealiner
Ok... I have only used the silicone grease that's designed for electrical contact protection in hostile (satlty?) environments. I need to research the subject a little more. Thanks
 
I

IWyk

Sealiner
basically you want to prevent corrosion between the two metal parts connected to each other(before they are connected).

Some of the silicone greases, as you mention(dielectric is one of them) is designed to cover the connection after it is made and not in between the connection to basically seal the outside. Not sure what brand you are using.

Much like the green and red sprays you can buy to spray on battery connections.
 
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