Dodgy Outboard

[OldDevonian]

I'm sure you have all seen this Q before, but:

I have a nasty little Merc 2.2 Pushing a Laser Sb3 keelboat. At full throttle it runs, then the revs drop and it sounds like it's going konk out, then recovers for a bit, then the process repeats. If I back off to 2/3 power it seems happy enough. Do you think this is a fouled plug, carb jet or cooling issue? The motor tends to spend most of its time at full power, and is stored in a dry place.

PS, is the rumour that 2 strokes are going to be phased out true?

Thanks for any and all answers.

 

[BarryH]

Sounds like A Fuel prob. Usual checks for blocked jets, float level. If it has an external tank, or internal for that matter, check fuel hose and that its able to breathe, let air in.

 

[aitchw]

Sounds like the float in the chamber or valve it presses against is sticking so there is a shortage of fuel at full revs but enough for lower revs.

Yes, they are being discontinued and some manufacturers have already stopped producing them.

 

[steve28]

mine does this when there is water in the fuel, to sort it out i drained the tank and the carb then refilled.

 

[Thistle]

I agree with other posters that this is probably a fuel problem ... but it could be almost anywhere in the system from a blocked tank breather to a dirty jet. I suggest that you drain and clean out the whole system and then refill it with fresh, newly mixed fuel. If you do come across some dirt which could be the cause, don't stop there: there may be more further along just waiting to cause a problem.

 

[Sans Bateau]

Just remember with all outboards, modern unleaded fuel has a VERY short 'shelf' life. Dont try to store more than you can use in a couple of months. Smell the fuel, is it still sharp, with lots of fumes or does it smell 'dead' with little vapour?

If the latter is true, replace it.

 

[TrueBlue]

OR could be constipated inline fuel filter. They're quite small and easy get blocked with bits and indeterminate gunge??

 

[ShipsWoofy]

Since 5 lts lasts me a full season, would it be beneficial to stump up and buy the 4 star replacement petrol instead.

For what it costs it is not a big problem, or will it make little or no difference?