Rpm's

[anthonyk85]

What would cause my 2018 25hp mercury not to build rpms when under a load

 

[Scott Danforth]

Wrong prop, bad fuel, too long of a motor, bad plug, low compression.....

Is this a new problem on an existing motor, or a new to you motor?

 

[anthonyk85]

Wrong prop, bad fuel, too long of a motor, bad plug, low compression.....

Is this a new problem on an existing motor, or a new to you motor?

Boat has a 20 inch transom running a long shank with a 9.5 pitch prop. Compression is setting on 115 on all 3 cylinders. Have not changed plugs yet. But got fresh fuel. But in the spring of last year I put a breakaway plate on it

 

[Scott Danforth]

I put a breakaway plate on it

Try it without the plate

 

[anthonyk85]

Try it without the plate

Ok ill try taking it back off but put it on cause I have tilt and trim on the motor and the river I run has alot of logs in it

 

[Faztbullet]

Leave the plate on and set cavitation plate about 1" below pad. Is it a EFI ? Could be a injector or ignition problem. If a carb model 4S could have a carb problem

 

[anthonyk85]

Leave the plate on and set cavitation plate about 1" below pad. Is it a EFI ? Could be a injector or ignition problem. If a carb model 4S could have a carb problem

Yes sir it's an efi. Ok thanks I'll have to take it to the shop and have it checked out. I know nothing about the 4 stroke engines