yamaha 2.5 carb problems

[causeway]

Does anyone know how to clean the carb on a f2.5 yamaha engine? The workshop manuals all seem to cost money online.

We removed the air filter and the carb(?) which had the throttle thingy inside.

We think water got into the fuel when the breather was left open, hoping thats the only problem anyway.

Its a 2.5hp fourstroke if that makes any difference.

 

[VicS]

Diagram here http://www.boats.net/parts/search/Y... Later 4-stroke/F2.5MSH/CARBURETOR/parts.html

More complex that I expected/ hoped but:

working where you cannot lose any tiny bits ( dont ask why I say that)

Remove take apart very carefully without damaging any gaskets, noting the settings of the adjustment screws.
Note the position of any little clip there may be between the needle valve and the float

Carefully identify and note the positions of all the bits esp little joint washers and O rings.

Carefully clean the float chamber and all jets and passage ways.

Reassemble. Return all settings to their original positions

Refit and away you go.

There is a repair kit... at aprice http://www.boats.net/parts/search/Y...ater 4-stroke/F2.5MSH/REPAIR KIT 2/parts.html

 

[rustybarge]

Does anyone know how to clean the carb on a f2.5 yamaha engine? The workshop manuals all seem to cost money online.

We removed the air filter and the carb(?) which had the throttle thingy inside.

We think water got into the fuel when the breather was left open, hoping thats the only problem anyway.

Its a 2.5hp fourstroke if that makes any difference.

Had the same problem with mine. Water gets in though the breather on top of the tank unless you close it in wet weather.......bad design or what!

Things are about to get even worse.....two bolts hold on the the carb air box,and the carb itself, and the gaskets, and the spacer gasket...can you believe it!

You will have to blow out the jets, use your own puff, and reassemble.
There's a little filter in the tank line, make sure you clean that too.

The solution: there is a water drain in the bottom of the carb bowl. You are supposed to open a tiny hidden recessed screw to open the bleed valve ....good luck with that.
I leave the screw permanently open, and block the end of the plastic drain pipe with a golf tee. I can drain the bowl by taking out the golf tee, and blow out the jets by blowing down the tube....sorted.

My son actually left the air vent open today, and I had to drain out the water and blow out the jets......only took a couple of minutes.

Yamaha engineering, very very disappointing!

 

[RIBW]

Does anyone know how to clean the carb on a f2.5 yamaha engine? The workshop manuals all seem to cost money online.
We removed the air filter and the carb(?) which had the throttle thingy inside.
We think water got into the fuel when the breather was left open, hoping thats the only problem anyway.
Its a 2.5hp fourstroke if that makes any difference.

Not of direct help but, on a charter earlier this year, I went through 3 of these outboards in a week because of 'carb problems' i.e. water or dirt. One of the machines was delivered to me mid-charter as 'pristine' and that also failed. The explanation I had was that the jets are very fine for fuel efficiency and emission control - great! - don't worry about safety. I would suggest that you get tooled up and as aware as possible of how to clear the carb just in case the motor stops, as it did for me, in a strong spring tide.
I solved my problem by shipping on board my own outboard - a 35 year old Mariner/Yamaha air-cooled (no impeller) 2 stroke that I bought unused in its box in 2011 - magic Yamaha engineering!
Best wishes Bob