Engine trouble

[Ctlangford]

Hi. I have a mariner 115ho 2017. Starts first time every time, but when getting in the plane about 4000rpm the engine seems to bog down, loses power and the revs jump around. Only happens at high revs. Any suggestions much appreciated

Cheers

 

[Mr Googler]

Fuel supply issue would be my first guess.

 

[Ctlangford]

Fuel supply issue would be my first guess.

Would this not be an issue at all speeds though?

 

[scottie]

Check your fuel filters

 

[Mr Googler]

Would this not be an issue at all speeds though?

Not necessarily

 

[Dino]

Check/replace fuel line, priming bulb and fuel filter from tank to engine. I had a similar issue on a Honda 75hp and it turned out my priming bulb was perished. It was loosing power at high revs. The filter/separator was fine so ran new fuel line and bulb back to engine and running 100% since.

 

[Ctlangford]

Not necessarily

OK thanks. Il get the filter changed then hopefully it will be sorted. How much do you think an engine guy would charge for this?

 

[Mr Googler]

DIY job. You probably have a pre filter/water separator filter somewhere and a fine inline filter under the outboard engine cover. Primer bulb is a good shout too for the cost of one.

pre filter might look something like this



inline filter (Check it’s the correct one for your model)
Genuine Mercury 115hp EFI 4-Stroke Outboard Fuel Filter 35-879885Q 1B366823 & Up | eBay

 

[Ctlangford]

DIY job. You probably have a pre filter/water separator filter somewhere and a fine inline filter under the outboard engine cover. Primer bulb is a good shout too for the cost of one.

pre filter might look something like this

View attachment 94619

inline filter (Check it’s the correct one for your model)
Genuine Mercury 115hp EFI 4-Stroke Outboard Fuel Filter 35-879885Q 1B366823 & Up | eBay

 

[Ctlangford]

I darent touch this stuff do more damage knowing me. A couple of hundred for a professional I guess?

 

[Mr Googler]

probably max!

where are you based?

you should carry a spare pre filter and know how to change it. Could get you home if it blocks at sea.

perhaps get the engineer to show you.

 

[Ctlangford]

Based in Plymouth. I think I will if that's the problem, which hopefully it is.

 

[AndieMac]

probably max!

where are you based?

you should carry a spare pre filter and know how to change it. Could get you home if it blocks at sea.

perhaps get the engineer to show you.

Hi C, as Farsco has implied, it is a really good idea to get to know the basics of your engine/boat systems functionality for your own and your crews safety and confidence into the future.
With outboards it will mostly be fuel or battery/electrical issues, cheers

 

[Ctlangford]

Hi C, as Farsco has implied, it is a really good idea to get to know the basics of your engine/boat systems functionality for your own and your crews safety and confidence into the future.
With outboards it will mostly be fuel or battery/electrical issues, cheers

Many thanks. I will sort it this week and keep you posted