mercury 30hp power issue

[mickey247]

Good afternoon, first time user of the site as i am in need of technical help. I have recently inherited a mercury 30hp outboard motor and a small RIB. Last week it was running fine, manged to get it to plane and keep it there, yesterday however it seems to have forgotten how to achieve full speed. When moving the throttle lever ahead from idle the revs increase fine. from about half throttle until full throttle there is no increase in speed, revs or engine noise. Being not a very technically minded individual i am looking for help for a probable cause and solution. Much obliged

 

[Bondo]

Re: mercury 30hp power issue

Good afternoon, first time user of the site as i am in need of technical help. I have recently inherited a mercury 30hp outboard motor and a small RIB. Last week it was running fine, manged to get it to plane and keep it there, yesterday however it seems to have forgotten how to achieve full speed. When moving the throttle lever ahead from idle the revs increase fine. from about half throttle until full throttle there is no increase in speed, revs or engine noise. Being not a very technically minded individual i am looking for help for a probable cause and solution. Much obliged

Ayuh,.... Welcome Aboard,... My 1st thought is ya got water, or crud in yer fuel,...

That could lead to crud, 'n water in the fuel filter, 'n carbs,...

 

[mickey247]

Re: mercury 30hp power issue

Ayuh,.... Welcome Aboard,... My 1st thought is ya got water, or crud in yer fuel,...

That could lead to crud, 'n water in the fuel filter, 'n carbs,...

Maybe, investigating the issue further, i can achieve full revs on fast idle, just not when in gear.

 

[racerone]

Re: mercury 30hp power issue

Motors will run fast in nuetral becauae there is nio work to do !!------Not a good test at all.-------It will do that running on 1 cylinder.--------------So your trouble shooting must start with a compression test.---Then check for spark on all cylinders.