4 Stroke Motor

[fishing24]

Boat rpms move up fine out of the water, however once in the water the boat just seems to idle.

 

[Bondo]

Re: 4 Stroke Motor

Ayuh,.... Welcome Aboard,.... What motor,..??

 

[fishing24]

Re: 4 Stroke Motor

Mercury 115 4 stroke - It runs fine, but it won't get up on plane. Changed plugs, changed water pump last year.

 

[Silvertip]

Re: 4 Stroke Motor

If it performed ok prior to this but doesn't perform now -- then it is not "running fine" as you stated. An engine with no load on it will appear to have no issues even if it is running on half its cylinders. What's the history here. Did this problem just pop up? Has the boat been stored or inoperative for an extended period? How old is the fuel? Details - details - details!!

 

[zopperman]

Re: 4 Stroke Motor

what boat... what load... (passengers, fuel, etc) I'd start with a compression check. Confirm all cyl are within 10% of each other

 

[fishing24]

Re: 4 Stroke Motor

i used it lot year before ,not as much this year ,started doing it about a year ago some time it will be fine ,went camping in june got it on plane, then
pulled kids on tube now can not get it to go ,it did it some last year too, put new fuel in it in June, new plugs month ago,rpm dont go past 2700 when
in water, out of water with hose it goes all way up,

 

[fishing24]

Re: 4 Stroke Motor

Could it be the fuel pump? if so where is it?