Outboard won't start!

jonathankent

jonathankent

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Outboard won\'t start!

Hi guys,

My Evinrude recently seized after leaving it for 8 months and somehow getting damp... result I stripped it down completely and sorted the seized problem. I have since put it all back together again and it is turning without problem - better than ever in fact.

So here is the problem... it won't start. I am thinking fuel supply problem. I have checked through the fuel system from tank outlet right through to the carburetor and there is fuel flowing all the way right into the main head, yet it won't start. Now this will show my lack of engine know-how... how does the fuel mixture get from the front of the engine to the rear in order for the spark plugs to work? I have also checked the spark plugs are working and are producing a spark. I am not 100% certain on the spark plug electrode gap though - anyone have reference to this?

I have tried to find a manual of some description on the internet, but have so far failed.

Can anyone shed any light on the possible problem and things I can look at.

BTW, it is an Evinrude 1988 4hp model BE4RCCS.

Cheers guys.
 
Re: Outboard won\'t start!

Have you checked to see the spark plug is getting wet?
If it is very wet, the choke may well be stuck open and flooding the engine with fuel.
If the plug is black and damp, then mixture may be too rich, or choke issue as above.
Have you changed the fuel for new? The fuel loses its octane by eveporation over a few months.
The again the fuel needle or the flaot valve seat may be blocked if there is nothing on the plug and its all dry.

Its also a worry that its turning over 'better than ever'. Are you sure that you are not suffering a lack of compression? The system needs to be airtight to work, as a two stroke depends on passing the fuel/air mixture to the crankcase and back through the transfer ports into the firing chamber to work, and pressure is built up to push the fuel/air charge through the system in time for the plug to spark.

Are you getting a nice fat spark with the plug out resting on the cylinder head?
Try 28-30 thou/inch for the plug, shouldnt be too far out.

Has this system got points/condenser?
 
Re: Outboard won\'t start!

At times the spark plug is damp to say the most, and when removing the plug, the piston head is also only slightly damp/moist. This is what has lead me to thinking it is a fuel supply problem. I haven't changed the fuel for new... so many posts on this subject /forums/images/graemlins/smile.gif. I haven't got a lot of mechanical knowledge on this... is the fuel needle in the front with the carburettor, and the float valve in the fuel line connected on to the side of the engine? I have tested the spark on a set of ladders and am getting a spark. The spark plug gap currently is set at 1mm - rather more than what you are indicating /forums/images/graemlins/frown.gif.
 
Re: Outboard won\'t start!

To sort out the seized problem I just took it all apart and lightly cleaned the internals. There was very minimal that would stop it from turning.. it just needed a bit of a shove /forums/images/graemlins/smile.gif. I don't believe to have made anything larger than before, i.e. cylinders, just cleaned off the crap that had prevented it from moving. It didn't move particularly easy until reassembling it fully and using the pull cord to start... I thought this was due to the lubrication that would now exist.
 
Re: Outboard won\'t start!

Yes removed the pistons and cleaned/checked the rings. They will rotate easily enough, until the piston goes back into the cylinder and then they are rather stiff to fit in, but the piston will still move readily when trying to start. All this went without dilemma and didn't take long at all.
 
Re: Outboard won\'t start!

Anything I can check to see if this is the problem? Would this mean that the position of the pistons would have been critical when putting it all back together again?
 
Re: Outboard won\'t start!

As Fullcircle has explained with a two stroke the fuel air mixture firstly enters the crankcase and is then transferred to the cylinder via transfer port. There were some links to some explations posted a while back but they were not particularly good. It might be worth looking in an encyclopedia, especially a children's one for a simple explation!

I can't access the engine diagrams on the BRP website this evening. But is this a two cylider engine. If so have you swapped the HT units around as I think with my 1984 6hp it is possible to do so and end up with it trying to fire on no1 cylinder when it should be firing on no 2 and vice versa. You have not done anything to disturbe the ignition timing under the flywheel have you?

It could be that the carb needs cleaning but if you dismantle it be sure to note where all the bits go and to preserve the mixture adjustment. And do it where you'll find any bits you drop.

If you are having problems always use fresh fuel. I know it keeps if stored correctly but it is daft to sod about with fuel that may be duff when you are having difficulties. It can lose the more volatile components which will make starting difficult

If it has electronic ignition, which I would have thought most likely, I think you will find that the plug gap should be 1mm (40 Thou)

You can get a "Seloc" manual from Amazon
 
Re: Outboard won\'t start!

Yep... its a 2 cylinder one.

I have taken the float etc off the carb this afternoon and removed from the main head unit. The fuel is deffinitely entering the crankcase, but doesn't seem to be reaching the spark plugs. What could be preventing this?

Ignition timing and flywheel... don't know 100%. I don't know enough to start fiddling, so just took it apart piece by piece and put back as it came off.

As a couple have said, I will try the new fuel anyway... thats an easy one to do /forums/images/graemlins/smile.gif.

HT leads are on the right plugs... one above the other with the lead to the side of each.
 
Re: Outboard won\'t start!

Did you disturb the crankcase oil seals?? If they were hard and got disturbed they will leak. There has to be a good seal for the petroil mix to get into the cylinder?

Try swapping the plug leads over first.... Keep it simple
 
Re: Outboard won\'t start!

From what I can remember, I don't think there were any seals, at least nothing rubber. At each end was a metal cover with a spring-like circle inside. All this went back as it came out and was greased to allow things to rotate. How much fuel should there be in the crankcase?
 
Re: Outboard won\'t start!

Jonathan,

there should be no liquid fuel. The carb atomises the fuel and makes the correct fuel/air mixture which goes first into the crankcase . The descending piston compresses the crankcase volume, forcing the air/fuel/oil mix into the cylinder.
If the crank seals are dicky then the mixture goes all to hell.
On a twin there will be three sets of seals. One at each end and one in the middle.
 
Re: Outboard won\'t start!

Just to throw in some random suggestions /forums/images/graemlins/confused.gif

Kill cord /forums/images/graemlins/frown.gif

Have you had the flywheel off? If so, was it keyed to the crankshaft? is it now?

Is the engine "trying", or is it just dead when you turn it over ?

I presume you're familiar with the practice of turning the engine over with choke off / full throttle to clear out a flooded engine?

Can you smell petrol from the exhaust?

Is there petrol dripping from the carb at all? ( = stuck float valve = flooded engine)

Dead certain about the spark?

Try a teaspoon full of petrol direct into the air intake. Any different?

Sorry, random thoughts.

Andy
 
Re: Outboard won\'t start!

I've looked at the engine diagram now. The HT coils are combined in one unit(unlike mine) so there should be no problem there.

The "metal cover with a spring-like circle inside" is the seal. If the bits the springs are round does not feel rubbery then they have gone hard and disturbing them may have been the final straw. As already said there is one at the top and one at the bottom with the springs on the inside ie facing the bearings. There is also a sealing ring in the centre below the centre bearing but I am not sure if that is a spring seal or not. The grease you applied will probably seal them initially so even if they have had it this may be a bit of a red herring.

I am mostly worried that you have disturbed the ignition timing but I have never taken the flywheel off mine so I dont really know what the pitfalls might be. You are sure all the wiring is reconnected as it was. I'm thinking about the leads between the powerpack and the ignition coil assembly, could they be swapped over or are they on a nonreversible connector
Failing that then blocked carb jets are something to consider. There may not be as much fuel getting through as you think. Did you look at the leaf valves in the intake manifold or did you not remove that.

The spark plugs are OK I suppose.

It is something I hesitate to use but it might be worth trying some Easy start If you can get it to fire and run briefly it eliminates most ignition system problems.

As said elsewhere there should normally be no liquid fuel in the crankcase but after you have been trying to start it with the choke pulled out you would expect the plugs to become wet.. Then you have to pull it over a number of times with no choke and the plugs out to expell all the surplus fuel from the the cylinders.

All the time you are trying to start this engine are you doing something to keep the water pump impellor wet. If not you will wreck that especially if the engine suddenly starts.
 
Re: Outboard won\'t start!

A very basic check for compression is to take out the plugs and place your thumb over the plug hole and pull the cord. If there is sufficient compression you should feel it trying to push past your thumb, and then noticeably suck it as the engine goes onto the inlet stroke.

Being a twostroke, the rings shouldnt rotate, there should be a pin in each ring groove to prevent rotation, because if they rotate the end of a ring could snag one of the ports in the cylinder wall.

I dont quite understand what you mean by testing the plug on a set of ladders. You have to test the plug on the engine by putting the threaded part of it on a metal part of the motor (with the plug cap connected) and pulling the cord. Testing the plug off the motor may prove the plug itself is ok but doesnt indicate the condition of the high tension circuit.

Good on you for having a go at it. Keep posting, and when you finally succeed you will have learnt a lot.
 
Re: Outboard won\'t start!

Seems to me you'tried most of the the other stuff, one of the later replies talks of leaf valves - I know them as reed valves, located fbteween the inlet manifold and the crankcase.

If they have dirt under them (could have some residue from the immersion), they will not seal and the transfer of fuel mixture from the manifold will not make it to the crankcase for transfer into the cylinder.

I maust say this would be reasonably unusual but possible.

Hope this helps.
 
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