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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28106
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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Are you up on portable Yamaha gen sets ...fuel consumption

Customer Question

are you up on portable Yamaha gen sets ...fuel consumption issue.....Yamaha ef6600de partable gen set consumes way too much gasoline and have problems with auto choke that I thought I remedied ....down in jungles
of costa rica parts here... but hoping it is an adjustment problem
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.

Locate the choke flap in the carburetor and see if it is staying wide open when engine is running, if not, see if spring is missing or broke,that keeps it open when not being used for start. You can always use a spring or wire to hold the choke flap open.

Customer: replied 1 year ago.
curtis sorry dont have contiueous internet down here in costa rica .....I believe choke flap is open as I have secured it open after starting ... any thing else influences gas consumption? there is a screw on the right side that looks like some kind of mixng screw ... but dont know ... fuel consumption is high ... a gal an hour under moderate load....others of similar size last several days on a tank .. this emptys out in 6 hrs???????? rpm dont seem excessive as they rise and fall with load by govenor....can yo give me a list of things that to check influence gas consumption to this degree...
Expert:  Curtis B. replied 1 year ago.

only other thing would be the needle valve and float in the carburetor, not controlling the fuel flow into the float bowl, where the gas is sucked into the engine. Needle valve may not be seating, or the float may be stuck or is filled with gas!

Customer: replied 1 year ago.
bought this used and it ran ok but had a auto choke issue a while back ..... never knew who might have adjusted what .... carb has been cleaned ... i do remember checking needle seat and float .... but i guess i could do it again.... when i had choke issue... auto type with bi metal that was not closing the choke flap and it ran rough and rich and spk plug was fouled ... after getting that to work it ran smooth but just consumes horrendous amounts of fuel... do you know what that screw down low on the right side of the carb does ////
Customer: replied 1 year ago.
on your suggestion on float needle seat issue ... wouldn't it run rough with not seatins proper ?
Expert:  Curtis B. replied 1 year ago.

I may have been a bit hasty, I thought you had said it was black smoking, showing to be flooding.. That was another question I was dealing with. Is the load close to the max. or not. The higher the wattage usage, the more fulel it will require.

Customer: replied 1 year ago.
Not sure if you can. Call me here...011(###) you have whats app...we can talk for free
Customer: replied 1 year ago.
In previous responce...load is moderste and other like size gen set i have been using goes for 3 dsys on a 6gal tank...this goes 1/2 day. ...runs fairly smooth but when load is increased there us noticable bogg down in rpm as gov responds
Customer: replied 1 year ago.
But out tools sèem to function
Expert:  Curtis B. replied 1 year ago.

All you can do is check he choke, and the needle valve and float. You may have carburetor with wrong jet for your altitude it has high altitude jet and you are close to sea level, the fuel consumed would be more because of the air to fuel mixture.

Customer: replied 1 year ago.
Is there no air to fuel mix sscrew adjustment on these carbs????.again do you have any idea what that screw on the right side of carb does????... its the onky adjustment on carb that i saw.....if i remember its a tapered end i would think it adjust you have access to real service manual for this ef6600de yamaha model????
Expert:  Curtis B. replied 1 year ago.

It is for idle mix adjustment, nothing else on the carb is adjustable, other than the external throttle adjustment. There is no service manual on the generator that I have ever seen.