Yamaha Malta o/b problem

[neil1967]

I acquired a Yamaha Malta outboard ( for the dinghy) with my yacht. The engine runs ok, albeit it's quite smokey. However, when put into gear, the engine drives, but won't rev - opening the throttle just results in the engine stalling (the engine will rev when in neutral). I am using the fuel that came with the outboard, so it is at least a couple of years old, and I don't know if the mix is correct (it is definitely 2 stroke though).

Given that the engine runs, but stalls under load, I assume it is being starved of fuel. Will old fuel give these symptoms, or do I need to look deeper - and if so, any ideas for what?

Thanks

Neil

 

[Ric]

Probably the fuel filter is blocked. The filter is a simple mesh at the bottom of the tank. To clean it, just swill some petrol around in the tank and empty it overboard (just joking!).

 

[Lakesailor]

Main jet blocked. Mucho cleano and new fuel.

It would be handy to have a sticky on this subject rather than a PBO special offer.

 

[VicS]

What Hp (3 or 4 )) and year? If we know those we know what detail to talk about

Fresh fuel is the first requirement. 50:1 mixture ( even if you later discover it will run on 100:1)


Check/clean filter as suggested ( may be in tank outlet on an in line filter before the carb.)

Carb may well require cleaning esp if left or run with old fuel.

Always check/clean/reset or preferably replace the plug.



Year is ID'd from a year letter on the ID plate on transom bracket. See http://www.boats.net/parts/search/Yamaha/Outboard/parts.html


Before using check cooling/replace pump impeller

Also check or drain and renew gearcase oil . If milky looking new seals are required

 

[rob2]

Just thought someone should add that the Malta is generally considered the top-of-the-range small outboard - well worth the effort to get it going properly. They're heavy but beautifully built. It does sound like fuel starvation and the most likely is a jet blockage through old fuel gumming it up. A thorough carb clean should fix it, but worth checking the filter as well.

Rob.

 

[davidej]

Probably the fuel filter is blocked. The filter is a simple mesh at the bottom of the tank. To clean it, just swill some petrol around in the tank and empty it overboard (just joking!).

Not all Maltas have a filter there. My one had a filter built into the petrol on/off tap. Caused me months of problems and numerous visits to so-called professionals until someone told me about this.Take the tap off and the pipe to the tank - it might be nestling in there. if you have one, chuck it away and fit a proper filter in the line.

Agree about fresh fuel

 

[neil1967]

thanks

thanks all - plenty of ideas there. outboard is on the boat, which is, sadly, a couple of hours away on a mooring, so i think this will be a winter job.

Neil

 

[Lakesailor]

Put it in the cockpit and do the cleaning etc there. Bung up any cockpit drain holes.
The only thing you'll be lacking is an air line to blow through the jets and passages.

 

[Boathook]

Not all Maltas have a filter there. My one had a filter built into the petrol on/off tap. Caused me months of problems and numerous visits to so-called professionals until someone told me about this.Take the tap off and the pipe to the tank - it might be nestling in there. if you have one, chuck it away and fit a proper filter in the line.

Agree about fresh fuel

That filter caused me loads of problems and the same proplems as the OP. Another area to be wary of is blocked cooling channels in the cylinder head and block. A quick way of checking is to take the thermosat housing off. Overall a very good engine.