1998 Mercury 25 Chirp

[MotorlessCSJ16]

My motor runs great but has a chirp/squeak noise after I run WOT/full throttle. I can cruise around all day and it's fine, no noise. But If I run at high RPM or WOT, it does it.

Any thoughts?

 

[andymach23]

Re: 1998 Mercury 25 Chirp

My 5hp Mariner 2-stroke kicker was making a chirping sound last year. The motor is warmed up in salt water and never flushed during the season. The chirping was evident as soon as motor was started. The chirp also followed the speed of the motor as it was rev'd.

I took the cylinder head off and found the the water channel that goes around the head was blocked by salt. I cleaned this out and started the motor and the chirp disappeared.

Just recently though, I went to start the motor after it had been sitting all winter, and it was seized solid. I have just stripped it down and found the oil seal housing under the powerhead to be seized soild with salt. I have cleared the salt out and will shortly put the engine back together.

I'm no expert at all but from my limited experience a chirp could be the early sign of problems and would be worth investigating.

I'll be flushing my motor from now on.

Cheers, Andy

 

[MotorlessCSJ16]

Re: 1998 Mercury 25 Chirp

The motor is flushed even after freshwater use...and the previous owner only used it in salt twice. So I doubt it's that. And it only does it after running wide open throttle (WOT).

 

[dsutherland1]

Re: 1998 Mercury 25 Chirp

My motor runs great but has a chirp/squeak noise after I run WOT/full throttle. I can cruise around all day and it's fine, no noise. But If I run at high RPM or WOT, it does it.

Any thoughts?

Did you find a solution to your problem? I am having a similar issue with a 40 HP outboard mercury mariner. Runs great at all rpm levels, but the noise you describe occurs at 4,000 and higher rpms.