Any ideas?

[creedsduckman]

Yes. I think you were right. Honestly when you typed that it was a foreign language to me. I should have looked it up. In the shop now. Hoping to get it back for the last few days of the season.

I didn't know what it was either until mine started to act up.

 

[stevena198301]

Had an old Merc that would act like that when it developed an air leak in the fuel system. Fell on its face at about half throttle but idle all day. Leak was a crack in the filter housing.

 

[mudder]

where is your gas line located and how old is it? I had the exact issue. lining in the gas line deteriorated. replaced the line and problem fixed.

 

[Pelican34]

Had an old Merc that would act like that when it developed an air leak in the fuel system. Fell on its face at about half throttle but idle all day. Leak was a crack in the filter housing.

When your mechanic services your VST have him clean your injectors and clean or replace the fuel line running to the injector rail. Also if you don't run a external fuel water separator add one.

 

[stevena198301]

When your mechanic services your VST have him clean your injectors and clean or replace the fuel line running to the injector rail. Also if you don't run a external fuel water separator add one.

It was an old carb'd 9.9. The housing got busted when someone replaced the fuel filter and overtightened the bowl that the filter goes in. Easy swap. But only a few things will make a motor (any motor) do that. Not enough fuel getting delivered (clog or leak) is the usual suspect.

 

[Pelican34]

It was an old carb'd 9.9. The housing got busted when someone replaced the fuel filter and overtightened the bowl that the filter goes in. Easy swap. But only a few things will make a motor (any motor) do that. Not enough fuel getting delivered (clog or leak) is the usual suspect.

stevena198301 sorry about that. I hit the wrong reply button. It was meant for Sweatlinner.

 

[Bruce White]

I have a 60/40 Evinrude jet. I carry a spare fuel filter. the filter sits on the port side under the housing cover. 2 minute fix and cheap. Seems the most likely to me. I had the same problem with a motorcycle and saw the crud suck up against the filter when I throttled up and lay back down when idling.

 

[Meathead2]

Was heading back in last week and at WOT it started to cut out. I opened the gas tank cap a little thinking it needed to vent. Vent on this tank is temperamental. Nope. Runs great at idle up to 1/4 throttle then it cuts out. Doesn’t die just bucks all over. Sure seems fuel related to me. Replaced the tank, new fuel line and primer bulb from tank to outboard connection. New gas. Fuel filter looks good. Briefly took it out and same. Starts right up, idles perfect, slowly throttle up to 1/4 it’s fine. Anything past that and starts cutting out. Tried squeezing the primer bulb while accelerating and same cutting out. Fuel lines look good, although they sure are wedged in there with seemingly tight turns. Unbent the lines while running and same deal.

2019 Yamaha F25 EFI

It’s been flawless until now

Thanks for any help

What type of gas are you using? Are you using fuel stabilizer to prevent phase separation? I have a 2019 70hp 4 stroke and I have to run only premium fuel. Might check fuel filter there are two if I remember correctly. Possible a calaspsing fuel bulb. Yamaha has a trouble site on line for your questions. Sorry I can't think of anything else. Oh, the dealer advised me to only run premium to prevent trouble over time. I don't know if this would affect your 25hp EFI.

 

[Tuleman]

Mine started coughing yesterday. Pretty sure it was weeds wrapping the prop and causing cavitation in the shallow water. Still, I'd greatly appreciate hearing what you find out. Thanks

Does your outboard have an electronic rev-limiter?

 

[stevena198301]

I have a 60/40 Evinrude jet. I carry a spare fuel filter. the filter sits on the port side under the housing cover. 2 minute fix and cheap. Seems the most likely to me. I had the same problem with a motorcycle and saw the crud suck up against the filter when I throttled up and lay back down when idling.

Junk in the tank will do the same thing.