Outboard help please.

Carmel2

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We have a 8HP Yamaha (4 years old) outboard which has never really started that well despite being professionally serviced each year (last service a month ago). It starts fine but when you come back to it after you have been ashore it is very hard to start and sometimes doesn't, I flush it regularly and run the fuel off to keep the carburettor clean, but the problems persist.

Any thoughts?
 

LONG_KEELER

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Normally the problem is either fuel related or electrical.

A small amount of fuel straight into the spark plug hole could help identify the problem.

Otherwise electrical.

Does the outboard run rough at all ?
 

Poignard

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I have a Yamaha (2B) and it's starting problems were caused by dirt in the carburettor float chamber from contaminated fuel that somebody gave me. The only solution to that is to clean out the carburettor, fuel lines and the tank.

Drain the old fuel into a tin and give it to some unsuspecting mug, who will one day end up posting : "I have a Yamaha (2B) and it's starting problems were caused by dirt in the carburettor float chamber from contaminated fuel that somebody gave me." :(
 

Seajet

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If it's that new it must be a 4 - stroke; are you laying it down in the way recommended by Yamaha ?

If not there's the chance of the lubrication oil filling the combustion chamber, in which case failing to start will be the least expensive of your problems !

I hope it's something simple a squirt of WD40 will fix...
 

Carmel2

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No it runs smooth once started, though you do get a nice white smoke cloud for a second or two. As for the fuel, the outboard was bought in Barcelona and has been to Turkey and back to Greece, so it's had many different sources of fuel. It's a pull cord start. So if it's an electrical fault, where do I start looking?
 

Carmel2

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If it's that new it must be a 4 - stroke; are you laying it down in the way recommended by Yamaha ?

If not there's the chance of the lubrication oil filling the combustion chamber, in which case failing to start will be the least expensive of your problems !

I hope it's something simple a squirt of WD40 will fix...

I keep it upright all the time, and yes it's a 4 - stroke..........
 

Seajet

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I presume you've tried new plugs ?

My Yamaha 4hp 2 stroke tends to go through the electronics ignition boxes, but as they're a tad expensive try everything else first !
 

AngusMcDoon

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My 9.9 had an automatic choke. Does yours? It's another possible cause for poor starting. If it's stuck off then cold starting is poor. If it's stuck on then you get soot on your plugs.
 

VicS

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No it runs smooth once started, though you do get a nice white smoke cloud for a second or two. As for the fuel, the outboard was bought in Barcelona and has been to Turkey and back to Greece, so it's had many different sources of fuel. It's a pull cord start. So if it's an electrical fault, where do I start looking?

Check for good sparks at each plug. Should jump best part of a cm

My 9.9 had an automatic choke. Does yours? It's another possible cause for poor starting. If it's stuck off then cold starting is poor. If it's stuck on then you get soot on your plugs.

I never use the choke, I did try on one of the non restarts but it made no difference.

If it starts from cold without any choke it suggest to me that the mixture setting is too rich or that it is tending to flood. Whichever, a situation which will make warm starting difficult.
 
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Binman

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I would take it back to whoever serviced it, any guarantee left on it. Ask them to start it, go for a walk have a cup of tea,then ask them to restart it in front of them. I find the company who do mine very helpful when it comes to little problems following a service if any. They will also collect. Good luck. I have my own ultra sonic tank, it's paid for itself over and over again, you can buy the correct chemical to clean aluminium, I got it to clean clock parts which are normally brass, that needs a different chemical.
 

tjbrace

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I have a Honda 6hp 4 stroke which also had starting problems despite being looked at by specialists. it works fine now since I cleaned a switch that detects if the engine is in neutral before allowing it to start. could be a similar situation.
 

GrahamD

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From my experience of having frustrating faults on 4 stroke outboards, the first thing to do would by to strip and clean the carb. We had a very similar fault caused by fuel residue which was cured by doing this.

If this does not work, (and this would be a long shot), we had a curious intermittent fault that frustrated us for ages, and which was eventually traced to a short circuit on the cable leading to the stop button on the end of the tiller. The outboard engineer said that this is not uncommon, and is caused by the frequent lifting of the tiller. The cure was to disconnect this button and rely on the kill cord to stop the engine
 
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