noisy 4 stroke

[cecilp]

have a 2001 EVINRUDE 70 hp 4 stroke that you cannot hear run on engine with cowl off but definately know it's running on the boat. no visible vibrations/loose bolts etc seen. what could problem be

 

[tblshur]

your best friend traded his 2 stroke with you and put your cowl on it just kidding .i would put a piece of rubber between the mount and transom also may have a pulley bearing loose or flywheel pull some covers and look at every thing while running

 

[racerone]

Can not hear it run on an engine stand ?-----But you can hear it rattle on a boat ?----What kind of boat ?

 

[Scott Danforth]

remember, your boat is essentially a bowl or a "speaker cone" the vibrations within the boat are amplified and broadcast upward.

sort of like owning a truck and cutting the exhaust off under the cab which makes the exhaust noises amplify within the cab.

 

[FreeBeeTony]

Evinrude made a 4 stroke?

 

[ahicks]

They relabeled one. A Suzuki I think?

 

[racerone]

Correct , those bigger Evinrudes 1999 / 2001 or so and later Johnsons big (eg 2005 model 225 hp ) and small were built by SUZUKI 1998 to 2005.-----Now the smaller 9.9 / 15 HP from 1996 to 2000 were their own design and not SUZUKI.-----Ok my years might be off by a bit.------I do not believe they sold many of the big ones though.-----I own 3 of the 40 HP EVIZUKIS for parts.----Owned a 2003 model JOHNZUKI for parts at one time too.